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Geo Metro Engine Questions



  • zaken1zaken1 Posts: 556
    The high idle speed when cold is caused by the thermostat being out. I replaced my stock 195 degree thermostat with a 180 degree unit of the same physical size. That was 250,000 miles ago; and I've never regretted it.

    Your car might be overheating because the electric radiator fan is not coming on when the temperature goes up. Mine did that; and I bypassed the stock fan control, and installed a toggle switch under the dash; so I can turn the fan on manually. I'm alert and aware enough that I can succeed with this; but some people do not watch the temp gauge. I also loaned the car to a friend; and forgot to warn him about the need to watch the gauge and manually turn the fan on; and he almost blew the engine when driving in San Francisco.
  • Hi.I have a 2ooo chev metro.4cyl.It has 105.000. when starting it puts out a fair size white cloud of white smoke.The cloud smells strongly of toxic emissions. once in drive it seems to disappear,the smell as well.When restarting with the motor warm,it does it to a less degree, then a cold start.It dosn't
    appear to be going through excess oil.a few months ago transmission fluid level was dropping rapidly,although now has slowed its intake.Thank's for any ideas You may have concerning this issue.Willie
  • zaken1zaken1 Posts: 556
    This sounds like either a leaking cylinder head gasket or a cracked head; and/or a leak in the transmission fluid cooler in the radiator. In these situations; it is important to monitor the coolant level; by directly removing the radiator cap (only while the motor is cool) and making sure the radiator is filled to overflowing. If there is an internal leak in the cooling system; it can enable the coolant level in the radiator to drop, while the reservoir level remains normal. And that can lead to sudden and unexpected destruction of the engine. It is also important to inspect the engine oil for signs of contamination by coolant. Sometimes coolant can be pumped into the engine oil through a bad head gasket or cracked head; which will keep the oil level up; but there will gradually become more and more coolant and less and less oil in the crankcase.

    If there is a vacuum operated transmission shifting modulator on this vehicle (which would have a vacuum hose from the engine to the transmission) it sometimes happens that a leak develops in the modulator or the vacuum hose connection inside the transmission; which enables transmission fluid to be pulled into the engine's intake manifold and burned. This would create the clouds of smoke you observed, and would draw the transmission fluid level down.

    If there is no sign of oil in the radiator coolant, and the coolant level is staying full; it is probably a modulator leak. If there is oil in the radiator coolant; it probably is either a head gasket or a transmission cooler leak.

    If there is no significant oil leakage from the transmsission anymore; worn intake valve stem oil seals will also pull engine oil into the cylinders and create smoke at start-up. This problem is sometimes more cosmetic than serious; but in more serious cases, it can involve worn valve guides as well as seals. So sometimes just replacing the valve stem seals will not be a complete fix.

    A radiator shop can run a pressure test on the cooling system to identify the source of coolant loss. This often will reveal leakage which is not apparent form a visual inspection.

    If there is a coolant leak; I have often successfully sealed such leaks without tearing the engine down; by using one particular product called Irontite Ceramic Motor seal. This is the ONLY product I would recommend for this purpose; despite any claims you may hear elsewhere. Please read and follow the instructions on the bottle. This product cannot be used in anti freeze; so the cooling system must be drained, flushed, and filed with tap water before use; and then drained and refilled with coolant again after the system is sealed. Irontite also makes another product called All Weather Seal; which is NOT suitable for this purpose. Irontite Ceramic Motor seal is sometimes available in some good auto parts stores; or can be ordered directly from
  • I have a 97 Metro that had been running great. Out of the blue it starting acting like the electrical was being shut off, or the fuel pump was shorting out. You would be going down the road and the engine would stop firing for 5-10 seconds and then pick right back up. It did this in all kinds of situations for sitting steal to driving at highway speeds. After a couple of weeks I took it to the shop and the mechanic replaced the computer. He reports the car will start and run longer but has the same kind of problem. He believes something is drawing too many amps from the computer causing it to overheat and then shut down.

    Is anyone familiar with this kind of problem? I sure don't want to go through another computer.
  • zendenzenden Posts: 62
    edited January 2013
    It would help to know the explicit reason why your mechanic believes the ECM is pulling to many amps. It is possible that he is just guessing. If the ECM is not grounded properly to the body it will pull to many amps and make it overheat; failure sometimes without killing it permanently. Check for continuity between ECM housing and the body ground. Ohms specs are good at .5 or below. If the car is definitely better with this new ECM; then your mechanic is heading in the right direction; But only to the degree that it would be ECM related witch rules out many other possibility’s; as in fuel pump, the pump relay and pump wiring. ect… The check eng light may not be on but there could be stored pending codes. You must first check for this! If there are pending codes, record them and look them up, they very well could help to guide you to the circuit of the primary problem. Ask your self, before the replacement of the ECM; where there any codes or pending codes? If this new ECM defiantly helps the situation some; then it could get worst like the last one. Check all connections coming out of ECM harness to the engine and engine compartment, also make sure all ground wires on this harness are in good condition and attached to eng and or body while making good continuity ( .5 ohms or less is great) Check very carefully for chaffed or burned wires that could touch moving parts like the axels, wires near the exhaust pipe or exhaust manifold can short circuit the ECM. Happy New Year! Zinden
    PS: I love these cars, mine averages 63.4 MPG at 58 MPH on a flat road every day. They are old tin cans on wheels, with moisture under the carpets the floor eventually rust with jagged edges, wires and connections fail under the carpets and rear seat always keep this in mind. If nothing has changed with new ECM, look in to fuel pump electrical. Connections and grounds. Under rear seat of all older GEOs (not sure about yours) Start there to track it down! For an interment problem like this, you could take the back seat out; attach a test light to fuel pump wire 12v wire and ground then drive to work. When the eng dies, look over your shoulder to see if the light is out then figure out why.
  • Guys If I can chime in on this topic. I am the 2nd owner of a 95 metro 4 door hatch back. 89k miles. I purchased it from my father in 2002 with 60K on it. My car had been pretty much trouble free except for a clutch replacement I did around 80K and a front alternator bearing at 83K. About two years ago I was experiencing similar problems as you have described. Then one day I left the house and about 3 miles down the road it just quit. I had a friend come out and tow me home.
    I am in my mid 50's and my hobby has been working on muscle cars and restoring them since I was a teenager. Professional I do maintaince and repairs on Cranes, heavy equipment and commercial trucks .
    I thought I would just check a few circuits find a short , repair that and be back on the road. I initially thought it might be a ignition switch but not that. After getting under the hood, I found the main 60 amp fuse that powers the fuse panel blown and a 15 amp fuse in the fuel injection circuit also blown as well. After and spending several nights last winter tracing wires I found where the alternator charge wire in the main loom between the fire wall and the engine had a wear spot most likely from vibration had shorted against the exhaust manifold and repaired that. I could understand why the 60 amp fuse that feeds from the alternator charging wire blew but not why the 15 amp FI circuit was shorting out. I replaced the main 60 amp fuse and the dash powers up and it cranks over fine but the entire ignition side of the system seems to be dead. I physically went thru every wire in the harness under the hood and can find no abrasions any where else in the system.
    I replace the 15 amp fuse in the FI circuit and turn the key on it blows As soon as the ignition key is turned to the on postion.
    I have a tester made for checking for shorts (Can't remember the brand right now) It has a signal generator you tap into the fuse holder or on to a wire in the circuit and a receiver that you run down the wiring harness to find the short. I has a indicator arrow that shows which direction to trace the affected circuit to locate the short. This procedure while tracing the FI circuit takes me to the fire wall where the main loom passes thru and then plugs into the ECM (as per wire schematic).
    I have not pulled the ECM yet because its way up in one hell of a hard part of the dash to get to. At this point I am pretty sure the FI circuit in the ECM is shorted. So I need to find another ECM for a 95 1.0 liter manual trans car is my next step. I have no Idea why the 15 amp FI circuit was not protected when it had the 60 amp main fuse between it and the short I found and it blew like it should have????
    The reason I posted this much was two fold. Maybe you have a intermittent short on the main power feed from the alternator around the exhaust manifold causing your igniation causing it to cut out intermittently but has not become a dead short yet! And second maybe some one out their has a ECM for my car they would make me a fare deal on???
    I posted my problem here last year but could never get any help. If you'll can bounce your Ideas off me so I would know if I am headed in the right direction, I would really appreciate it! Thanks Guys, I hope my input has helped you also. P.S. I have seen these cars in North Central Texas wrecking yards with 250k on the!!! One good thing is we do not a have rust problem in this part of the country!!! Best Wishes
  • zendenzenden Posts: 62
    edited January 2013
    I will look in to this more and answer tonight. for now this is the interchange for the ECM if needed.
    For Federal emissions standards
    FIREFLY 95 (ECM); 1.0L (3 cyl) METRO 95 (ECM); 1.0L (3 cyl),
    Controller (ECM) Part Numbers are:
    30013137, 30016396, 30017506, 3392050G20, 3392050G21, 3392050G22,
    For California emissions standards
    METRO 95 (ECM); 1.0L (3 cyl)
    Controller (ECM) Part Numbers are:
    30015669, 30016395, 3392050G10, 3392050G11
  • zendenzenden Posts: 62
    edited January 2013
    I am not sure why you blew 2 fusses at once; normally it’s not the ECM! Sounds to me like the power cable that shorted out on you has melted in to some wires around the junction block; you may need to unbolt it, turn it over and inspect. My time is limited to help but will; if time will allow me. I think the power supply to this cars fuel pump and injectors go through the fuel pump relay independent of the ECM! So then the FI fuse that is blowing out when the key is on is then also the fuel pump fuse. This may sound puzzling some; but it is a negative output signals from the ECM to injectors. Try this, pull the pump relay out of that block; put a new 15 AMP fuse in; turn the key back on; dose the fuse still blow out? If not; you know where to start looking for the short. Hope I am on the right track for you. I will look at this closer n get back with you tonight. Any extra input from you will help. I have all info at my finger tips here.
    ------ ----- ----
    Message update: I’m going over the schematics now.
  • zendenzenden Posts: 62
    You said, 15 AMP( FI ) fuse? If you are speaking about fuse #7, 15 Amp under Hood, Power distribution box, #7, 15 amp is your Main. Did you know this? I thought you where speaking of FI; As in Fuel Injection! Sorry
  • Thank you Zenden for the very thoughtful feed back. I was aware of the negative or (ground) signals that the ECM sends out to active on monitor various sub-systems. Its been over a year since I worked on my Metro and I will have to get it back in my shop to check out the items you refer to. I'll post back with more info as soon as I can come up with it.
    Also my 95 is a 4 door hatchback and the body style has what I call square edges. Their is a newer 2 door hatchback in my area that has the more round sleek body style. From the research I've done in the past a lot of the interior and mechanical parts are interchangeable? The reason I ask is this 2 door has been parked in the same spot for about 9 months or so. It still has a paper tag for a license plate. So I figure the car broke down right after it was acquired. I was thinking it would make a good parts car to have around. I can tell from the road the clear coat is pretty much gone. I was thinking of offering $300-$350 for it. What do you think?
  • zendenzenden Posts: 62
    Without farther research drive trains should all be the same, if they are both 3 cyl. Four cyl, verses 3 cyl drive lines are like apples and oranges. The chances of this being a good parts car may be slim, because many where 4 cyl automatics with air! It would be a shame to buy a parts car and come to find out the only thing that you could use off of it where; dash parts, front seats, half the carpet, window crank handles, hood, fenders, headlights, front bumper and grill. Two door and 4 door GEO’s have a different exhaust systems. Also all glass is all together different.
  • Wow, I would never thought their would be that much difference in the two. I will check to see if its a 3 cyl like mine and consider everything you indicated before making a offer if any.
    To the original problem I posted on. The main fuse/relay box had blown a main 60 amp fusible link and the FI 15 amp fuse. After looking at the wiring schematic, I figured the alternator charge output wire would be the most likely to be grounded to blow the main fusible link. Their is extremely limited access to the engine harness the way it wraps around between the firewall and engine. So I had unhooked the harness being careful to use an electricians labeling kit to mark where each connector went. I opened up 90% of the engine harness for inspection and the only thing I found was the starter solenoid wire was grounding against the intake manifold. I repaired that section and installed convoluted sleeves over the areas of the harness I had opened and reinstalled it around the engine in the original location.
    I checked closely as you suggested under the button side of the main fuse/relay box but found nothing notable.While using my Power Probe circuit tester with the ignition switch in the on position, The fuel injection and fuel pump relays are functioning properly. The one problem I have found is that the pink/white wire that comes from A-23 on the ECM to the fuel pump relay does not seem to be sending a ground signal for 2 seconds when the ignition switch is first turned to the on position. So I used my Power Probe tester to apply a negative signal to the pink/white wire at the relay with ignition in the on position and let the fuel pump run about 30 seconds, it seem fine. I have B+ at the coil and engine cranks over fine but never tries to start.

    I did find a 15 amp fuse blown in the interior fuse panel in I think the #4 location. Its the first 15 amp fuse location on the left side row down from the top. I used the power probe tester to apply B+ and it popped the breaker at once. I think my manual say it runs Fog lights,marker lights, license plate lite and some instrument panel items. I also placed a good fuse in the bottom empty slot of the fuse panel ,That is used to operate the MIL system but could not see any new light come on on the instrument panel lights. I am not sure what the MIL light should even look like on a Metro. I have used the lights :sick: before on a 86 Camero OBD1 where you counted the flashes to access the trouble codes.

    I have a subscription to AllData.Com for access to the Factory manual. The Diagnostic Circuit Test recommends unhooking and/ or back probing connectors/ terminals on the ECM. Can you give me any Ideas on how to gain access to the ECM. It is buried way up in the top left area of the dash. It almost looks like the drivers sider door or fender needs to be removed to get to it.
    ZENDEN I really appreciate any help on this . My metro has been down for 2-1/2 years now and I am about at my whits end with it !!
  • zendenzenden Posts: 62
    edited January 2013
    Don’t give up! We will figure it out, just not over night. This is all right up my ally, but have a lot on my plate also; going away this weekend. So don’t ever think that I have bailed out on you. Give me a summery of what happens when you turn the key on to start. As in FI fuse blows? Starter turns, lights on dash in run position? Pump running? Negative impulse to injectors? 12V to injectors as needed also? Ignition Spark? This car have a security system ? Oil level in engine full? After I get this data from you; I will take a closer look at the schematic to figure out how the 15 amp FI fuse links into what. To make sure that you and I are on the same page, Any info that you can give me on FI fuse will help also, AS In… The location of it; Under hood, right? Fuse #7 ? What dose Alldata say about it ( FI Main? ) I think what you have described is the fuse marked on the box cover as FI; and I think that it is really for the main relay. This is why I need this info, and then I will do my homework and should be able to help you diagnose it. (Time to tune in!)We will not go on a wild goose chase here, as long as we have good communications. Thank you Dennis
  • zendenzenden Posts: 62
    edited January 2013
    I checked deeper into the interchangeability of the two cars. 1995 and newer Metros with 1.0 L did not have A/T.
    All Brakes, Rotors, Pads, Struts, Calipers, are all the same on 2 door, and 4 door cars with 3 or 4 cyl engines. (Most likely all the same Wheel bearings). I believe the wheel base is longer on 4dr GEO also.
    I wasn’t ready to say cut open the harness yet :) I want to identify for sure what FI 15 fuse circuit is first. This way I can figure out where it may have shorted to ground when that wire got hot. I will look into it, and how hard it should be to pull the ECM.
  • the blown fuses so I replaced both. The Thanks Dennis,
    I can not express enough thanks for you taking the time to help me with my Metro's problem. Just to clarify its a 4 DR Hatchback 1.0 Lt engine with manual transmission and A/C. Its pretty much as basic a model you could get except with A/c. I am the second owner, I purchased it from my father (53K) about 10 years ago with 53K miles. It had been very reliable over the years except for a clutch I put in and a front alternator bearing freezing up at about 85k. I think I am @ 89K now. The car has been unmolested by any outside mechanics. I have kept up on all the maintenance including replacing the timing belt and tensioner bearing @ 60K.
    The current problem started after a 110 mile trip to my new home south of Dallas,Tx . It sat about two months, then I decide to take it to town and three miles later it just quit. Looking back it it sounded a little erratic while cranking up but seemed to be running fine other wise. Then it just quite like I had turned the key off. After towing it back home I found the 60 amp fusible link in the relay/junction box under the hood blown plus the 15 amp FI fuse in the same junction box blown.
    I could find no evident reason for60amp held but the 15 amp kept blowing each time it was replaced. After looking over the wiring systematic I decided to remove the wire harness from around the engine for inspection. I found a area in the starter solenoid wire that had been grounding out. I repaired it as needed, but that did not explain the other fuses blowing. I spent many hours searching for a cause and finally just put the repair on the back burner. Thats when after 2 years I replayed to one of your post last week.
    So I hooked back up the harness I had removed for repair. Now the FI fuse that had previous been blowing was now holding (go figure). But the GEO still will not fire up cranks over fine but will not try to fire. With the key on I have B+ voltage at the coil. I have checked the FI relay and F -pump relay. Both are activating normally except the fuel pump relay @ the pink wire is reading a grounded signal. If I apply B+ to pink wire in the fuel pump relay the pump seem to run fine? When I use my power probe tester to apply B+ voltage the fuel pump runs. It does not run when I first turn the ignition as it should. I have checked the under dash fuse panel and #3 labeled Tail 15 amp fuse is blown. I have rechecked it with my power probe tester and it blows the breaker at once.
    SO THE CURRENT SYMPTOMS ARE: #3 15amp tail fuse in the underdash fuse panel has a dead short. Cranks but no spark at plugs even though B+ voltage at coil. I have not been able to check the injector for voltage signal. I am not sure how I will do this. I have a Fluke multi meter that has a hold option. Should I hook my leads to the wiring connector in DC mode and try to capture the cranking voltage where the injector harness plugs into the injector and do it that way?
    After finding the #3 Tail fuse blown, I have started trying to trace the short in that fuse in the under the dash panel even though it doesn't seem to me it has anything to to with my no start situation. I started by unplugging each circuit connector and testing to see if the #3 was grounded after each was removed. I found that when I unplugged what I believe to be connector #1 the ground signal ceased @ the #3 fuse. I have not found the wiring for this connector yet but I found 4 wires that had a ground signal in that connector. 1st Green/red, 2nd green/yellow, 3rd red/yellow, 4th white wire.
    I believe the last thing you ask was on the dash lights. With the key in the on position both fasten seat belt lights are on, lock door light is in and the low oil pressure light is on.
    I know this is a lot to take in. I wiil indeed be patient, so take as much time as needed to think about this mess I have. I am by no means a expert but can do about any test you want me too, and have the equipment to preform them. Thanks Again!!!
  • zendenzenden Posts: 62
    edited January 2013
    You can test injector signal with a noid light; About $10 dollars I guess, from Autozone. Most likely you will have a negative signal ; I don’t think that your ECM is bad. But I also don’t think that the noid light will flash when you crank it. Because your Fuel pump relay is not activating! If it is not activating then no power will be supplied to the yellow wire at the injector. Do not connect 12 volts to that yellow wire to test it because you will be bypassing the needed inline resistor that sits between the relay and injector. First are you getting spark to any of the plugs? If so most likely you can start it up by adding power to the pump and the Wht/Blu wire that connects under the Fuel pump relay. That White and Blue wire is the power supply for the injector!!!! Figure out why the relay is not working; switch it with another known good one. On that relay are 4 terminals that are marked somewhere; ( look closely on the mail and female side of that connection.) (#1 connector is Black/White wire, 12 V With ignition in run or start position) (#2 connector is the Pink/White wire, The Trigger Negative - signal from ECM ) ( #3 is Pink wire 12V output to Pump ) (#4 White/Blue wire, 12V output supply to Injector. The Car may start up if you ground #2 to Bat negative and crank it. It won’t hurt anything to try. I hope this info helps, Dennis
  • Both the fuel injection relay and the fuel pump relay are activated with the key in the on position. So the relays them self are working. From my testing I believe on the fuel pump relay #2 connector the Pink/White wire, is not getting a signal from A-23 on the ECM. I can apply B+ to the #3 connector and the fuel pump runs.
    I forgot but I have a high end electronic test light that uses low power LED's to indicate signals, Red led for positive and green led for negative signals. I purchased it about 10 years ago to check injector signals on my 86 IROC.I will do those test with it.
    I fell like there are no signals coming from the ECM. The TAIL 15amp fuse on the interior panel is shorted. The diagrams I look at show the ECM is powered from this circuit. I unplugged the connectors to that fuse panel one by one and probing the TAIL fuse socket until I found the one that when unplugged removes the short/grounded signal from the Tail fuse socket. That connector is C1. I found 4 wires on that connector that had ground signals. One was a solid white wire that schematics show to be the wire that powers the ECM.
    My thoughts are that until I solve why the white wire is grounded I can never power up the ECM. I would like to be able to disconnect the connector that contains the white wire from the ECM and back probe it at the connector. Would that not indicate if the problem is in that area of the harness? Or could I probe the pin the white wire connects to on the ECM with the connector removed and if I find a ground signal would that indicate the ECM is shorted internally?
    I am not sure how I am going to gain access to the area the ECM and this wiring is installed in? Maybe remover the instrument cluster would provide some room to do what I described.
    One last Idea I have is because I found 4 wires grounded in connector C-1 in the back of the fuse panel. I can never remember any grounds ever running thru a fuse panel except one that grounds the fuse panel chassis to the cars chassis where bolts mounts it onto place. Could maybe all 4 of these grounded wires be melted or smashed together some how at some area where they also contact a area that is grounded? It is a very short distance physically between the ECM and the interior fuse panel. That should narrow down the area of the affected area!
    I have subscription to which provides access to OEM manuals and all OEM Technical Service Bulletins. It shows a to Use a ECM #300009394 manual trans and #30017413 for auto trans cars. Are all the ECM model,year and engine specific. That could make it really tough to find a replacement.
    Thanks Doug
  • zendenzenden Posts: 62
    edited January 2013
    What I would like to hear is what where your test results from the last message that I sent. Did you ground terminal 2 on the Fuel pump relay and did the car start up?

    ECM’s are on the right side of dash. Usually just take out glove box. I still don’t think you need ECM. It still sounds like that power supply has melted a wire some ware causing a permanent short circuit.

    Part numbers for your cars ECM are below.
    Fits your GEO Metro 1995 1.0 L 5spd Trans
    Call junk yard to verify this info; $50.00
    They should be all over the internet if you cant find one near you. I could get one and ship it if it was absolutely necessary. I don’t think that old ECM like that are worth much, price only depends on your location. I am between Baltimore and Washington. I will read your message again and do more research on that short that you just described. Sounds like you are on the right track, Good luck!

    For cars with Federal emissions standards
    FIREFLY 95 (ECM); 1.0L (3 cyl) METRO 95 (ECM); 1.0L (3 cyl),
    Controller (ECM) Part Numbers are:
    30013137, 30016396, 30017506, 3392050G20, 3392050G21, 3392050G22,

    For cars with California emissions standards
    METRO 95 (ECM); 1.0L (3 cyl)
    Controller (ECM) Part Numbers are:
    30015669, 30016395, 3392050G10, 3392050G11
  • zendenzenden Posts: 62
    edited January 2013
    Check all of these things and let me know if all is well; if not then I need to know what failed.
    FI fuse hot all the time! Supplies constant 12V power to the Main Relay for when needed (MR) Main Relay terminal #4; MR also needs 12V at terminal #1 with key On! Terminal #2 is to be grounded by ECM signal when key is on! When key is turned on, power must come out of terminal#3 to power up the injectors and to send power to the Fuel pump relay terminal #4.
  • zendenzenden Posts: 62
    Schematics show me that there is no link at all between the ECM and the tail light circuit. There is an idol up diode linked between the brake signal and ECM that speeds the idol up. But that is not going to blow a fuse, so forget that! The only link would be a short circuit!
    Test this and get back with me please: When dose Tail fuse blow out, with switch on or off? Also key on or off? What ever you have to do to blow that fuse; do that same procedure again; but this time with the (Light 1 Relay removed!)
  • heavyhookheavyhook Posts: 12
    edited January 2013
    We had a storm come thru last Thursday that created some damage to my house, I had to spend the weekend repairing. So I have not been able to work on the Geo since last Wednesday the 9th. This morning we got up to 1/2" off ice on everything which pretty much melted away during the day. I will try to get out and do the test you requested tomorrow.
    One thing I discovered is my Geo is a 93 not a 95 like I told you. Also the wiring diagrams I using from AllData show they are for a 93 Suzuki Swift. It actually shows the white wire from the tail fuse connecting thru C6 or C8 (hard to read which) going to pin A26 for TBI systems to the ECM. Also white wire from tail fuse goes thru C4 to the clock, radio, data link connector. C6 to dome light and C2 to ignition switch (key warning).
    I will test to see if the tail fuse plug is grounded with the key off, I'm sure it is if IG switch on? On the fuel pump relay I will add B+ to fuel pump terminal #2 and try to start and check for ground signal @ injector if still no start situation. I was able to run the fuel pump before by adding B+ signal to Main Relay fuel pump terminal #4 with relay activated. But I will check the voltage at terminal#2 and I will make a note of that and include in my next post tomorrow! One last thing I can find no Light 1 relay on my drawings. I think I need to find the same ones your using somewhere! Thanks Dennis
  • zendenzenden Posts: 62
    edited January 2013
    No problem! I will check in to the 93 model and let you know if I see anything; the wiring is a little more simplified. If your car has the federal emissions standard, the ECM interchanges with:
    FIREFLY 92-93 (ECM); 1.0L (3 cyl), Hatchback, base and LSI, MT
    METRO 92-93 (ECM); 1.0L (3 cyl), Hatchback, base and LSI, MT, Canada
    METRO 92-93 (ECM); 1.0L (3 cyl), Hatchback, base and LSI, MT
    Part Numbers 30010098, 3392060E30, 3392060E31 and 3392060E32
  • ZenDen, I'm sorry about getting the year wrong on my Geo. I was able to see the bottom of the ECM today while looking for any wire damage above the interior fuse panel. It is located above the interior fuse on the farthest left close to where the left fender is but behind the dash cover. My ECM is # 3392060E32. While checking the condition of when the tail fuse grounds out as you requested I found it was no longer shorted out. I checked to make sure all the connectors on the back of the inside fuse panel were connected securely but could find nothing that looked suspicious. I am really troubled by this. You also requested I test the fuel Injection and fuel pump relays and here are those results.
    Fuel Injection Relay
    Key on #1,#2,#4 =B+ and #3 negative
    Key off #1,#3,#4 =negative and #2=B+
    Fuel Pump Relay
    Key On #1,#2,#3=B+ and #4negative
    Key Off#1,#2,#3,#4 negative
    Tail Fuse has B+ key on or Key off
    Fuel pump relay #4 does not get B+ when key is turned on for first 2 seconds or any other time that I have found. When I apply B+ to #4 fuel pump runs until B+ is removed. I have not tried to start with pump running continuously with B+ added to #4. Is this ok? No problem with fuel pump running all the time?
    I tried to start the engine after no blown fuses existed by using a starter jumper button attached to starter solenoid and placed about 20 cc's gas in throttle body but engine still did not try to fire up. I used the starter button so could be under hood to observe things while cranking.
    I did not get any signal at TBI injector wires! Also I installed a fuse in the MIL fuse socket after no blown fuses but no extra light showed up on instrument panel.
    What do you think about the short in Tail fuse going away? Could it possible have something to do with left side combination switch that operates headlights, parking lights and turn signals?
    Thanks for your input!!!
  • zendenzenden Posts: 62
    edited January 2013
    Time to put my thinking cap on and its late at night. I just got your message Thursday 11:45PM Eastern time. I will look this over and get back with you ASAP; Good work!
  • zendenzenden Posts: 62
    Turn Key on and ground terminal #3 on the fuel pump relay; ( when grounding this terminal leave the relay in place) The car will most likely start because of bad pump relay, or bad ECM, or a bad connection between ECM and pump relay. It sounds like it could be a bad ECM but the car may still run fine when you trigger that pump relay to ground. If the pump runs but the engine still won’t start when you jump the pump relay by grounding its terminal #3; then check for injector signal again. If you have no injector signal or fuel pump signal or FI signal from ECM then it’s a good chance it will be bad ECM. I could understand 1 bad trigger wire coming out of it but not 3. If necessary, I can identify the trigger wires for you to test after your finished this test. Dennis
    PS:I’m not sure about that tail light short circuit at this time with out looking deeper into the schematics.
  • Grounded terminal #3 on the fuel pump relay as requested. The fuel pump was running but no sign of it trying to fire up. I even primed the throttle body body with 20cc's of gas but not even a burp. I rechecked The signals at the injector with the key on and off. I'm not really sure if I am checking the right wires . The plug in connector that appears to power the TBI injector connects on the side of the throttle body that faces the passenger side front tire. This connector has two wires one Yellow and one Yellow/black. Key off both are grounded ,with key on yellow/black wire grounded and Yellow is B+. I fell like I am dropping the ball here some where. I cannot find the right wiring diagram in what I have for TBI system only FPI system. Coils hot, I verified fuel is reaching the throttle body. But were getting no spark and It doesn't seem like the injector is opening during cranking to allow the fuel thats needed.
  • zendenzenden Posts: 62
    You are checking the right wires; the yellow one is power from relay; the yellow black from ECM. I made my email address public for this forum, but for some reason it can not be viewed by other members. I would like you to contact me at I will send to you the schematic that you need. Dennis
    PS: I’m leaving town very soon, and may not come home till spring! Email me ASAP
  • zendenzenden Posts: 62
    Alldata has that info, it is sometimes hard to find. This is the way in to find it!!!! Under Diagnosis and Repair/ (on the right, click) Power train Management/ (then on the left, click) Electrical diagrams then/ Electric Power train control module.
  • chicorybreathchicorybreath Posts: 1
    edited January 2013
    hi - i recently came into the possession of my friend's treasured, well-maintained '92 Geo Metro. i am the third owner and not terribly familiar with its behavior previously. i know he drove it from New Orleans to Seattle and back, but recently it was being used as a daily driver just around town.
    it started overheating and my friend discovered the fan was not always turning on when the engine heated up. he would stop and fiddle with the connection to get it going again. we also assumed that there might be something wrong with the coolant intake/circulation. turns out the head gasket needs to be replaced.
    my query to those of you who may be in the know is, can you recommend a mechanic who wouldn't laugh at the prospect of fixing this little car? i found a play by play instructions, but it seems like a solid amount of time is needed to devote to resolving this issue. i don't have said time, but really enjoy the car and want to see it moving again.
    i took it to a mechanic locally who told me i should just donate it b/c the cost to repair it would be over $1800.
    i would love to know if anyone in this forum has any suggestions or knows of a mechanic in New Orleans/South Louisiana who wouldn't see working on this little guy as a lost cause.
    thank you!
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