Chevy Blazer Starting and Stalling Problems

cuman3242cuman3242 Member Posts: 1
I have a 1974 Blazer with a 305 in it, I just replaced spark plugs, cap, rotor, wires, fuel filter, some hoses and PCV valve. It starts up strong, runs fine for a bit - drive it around the neighborhood - then once I come to a stop it basically dies on me, sometimes it will start right back up again - sometimes it will just crank and crank.

What other things should I be looking at, fuel pump? Can a bad coil cause this??

I would appreciate any help, thank you.


  • tidestertidester Member Posts: 10,059
    I changed the title of this discussion to make it more general.

    tidester, host
  • repairdogrepairdog Member Posts: 948
    This is reaching back, but no computer and manual fuel pump with a carb. Float level and needle/seat would be one to look at - does this have an air idle solenoid on the carb? Isn't there a small brass filter in the carb base where the line screws in too. Fuel pressure should be checked (believe 9-11 lbs but check online to be sure). Coil could heat up and die as well as wiring to the key switch could be loose.
  • bigjoe85bigjoe85 Member Posts: 5
    I have an 01 blazer 4.3 vortec and Im having trouble I think with the fuel system. When I would pull up to a stop light and sit there longer than 5 min. it will cut off on me and and now its shutting off while im driving down the road. I have no problem starting it backup though. Fuel pump or possibly injectors?
  • repairdogrepairdog Member Posts: 948
    That or coil, sensor, MAF, vac leak, cap/rotor/wires/plugs etc - mileage? First when was the fuel filter changed - first place to look and its $15 ($75 with labor). Air filter not too dirty? Fuel system has a test port on the metal line that requires a special valve to connect and then ckeck the pressure. 60psi min with key on engine off (start pressure) and 54psi running. If those check out then on to electrical/sensors/etc. Any SES light on and codes?
  • bigjoe85bigjoe85 Member Posts: 5
    well the milage is about 83,000 havent checked the fuel filter yet(where is that located by the way) air filter looks good and also can i go to a local parts store to have the lines checked?
  • repairdogrepairdog Member Posts: 948
    Fuel filter should be changed every 25-30k miles and is under the drivers seat area under the frame on the inside. Its always a pain to change up there - $10-15 part and about $50 labor. One end is quick connect squeeze tabs to release (after pressure released) and the other end requires 2 open end wrenches. Have to take the bolt out of the plastic holder also to get the filter out.
    Pressure test NOT normally done by auto stores but they may have a free reantal tester to use at home or take to a shop and they will do that and the filter plus analyze the problem so you don't throw too many parts at it.
  • jmojardinjmojardin Member Posts: 3
  • repairdogrepairdog Member Posts: 948
    First change the fuel filter a $15 part, then if problem still happens test the fuel pressure at the test port on the metal line at the top rear of the engine. Its a special tester and once you have it or get a shop to do it the pressure should be 54psi when running or alittle higher (but not lower than 53) and if there is a starting problem its 60psi with the key on engine off. Also check all connectinons at the top of the tank and there is a fuel pump relay in the fuse box under hood.
  • bigjoe85bigjoe85 Member Posts: 5
    Ijust got a fuel filter for my 01 blazer and i need help on switching the old one w/ the new one. How hard is it, should I let a mechanic do it, and what tools do I need if I replace it?
  • bigjoe85bigjoe85 Member Posts: 5
    P.S. very limited funds.
  • repairdogrepairdog Member Posts: 948
    One end is a snap or quick disconnect that you squeeze the 2 tabs and it pulls off (after pressure released). The other end requires 2 open end wrenches. The bracket it is in is held on by one 13mm bolt to the frame that has to be taken off to get the filter out of the bracket and the lines are simply snapped in to the top of that bracket. You will get gas on you and its kind of a pain but shops charge about $35-50 to change so up to you.
  • niteman18091niteman18091 Member Posts: 8
    When I drive down the road sometimes when I step on the gas the engine bogs and stalls, if I quickly put it into neutral and restart it will have all kinds of power for a few miles then do the same thing. I relaced the fuel filter, fuel pressure regulator EGR valve, spark plugs and cap, I put a fuel pressure gauge on the test port and it reads with KOEF 65lbs. and with the KOER it reads 58lbs. I also put a vaccuum gauge on engine and could find no leaks. Why does this do this and how do I correct the problem? Help this is a safety issue, my family uses this vehicle.!!
  • repairdogrepairdog Member Posts: 948
    What year and mileage? Aby codes (SES light on) and if so post them.
  • niteman18091niteman18091 Member Posts: 8
    No codes come up until after it happens then it comes up oxygen sensers port 1 and port 2. You can step on the gas and the engine just bogs it has absolutely no power . Put the car in neutral ( while still moving ) count to 3 and restart and have all the power you want. Tried Hi test gas , fuel additives, still happens! This has me totally confused. Need help, someone told me to replace the computer.
    The mileage is 124000 and the year is 1996
  • repairdogrepairdog Member Posts: 948
    Clean MAF sensor - tells computer mass airflow or rich/lean settings - could trigger the O2 sensor code if too rich. Check/clean EGR. This does have the newer style injection so could be fuel pump heats up and pressure drops - have to test at test port. Coil could be failing due to overheating due to ignition module never shutting off so always a low voltage to it. On from there.
  • ednedy07ednedy07 Member Posts: 2
    Last night on my way home from a friends house I stop'd to put gas. I parked did the usual routine and as I came back from paying for my gas I lined up my car. I turned it off and when I finished I got back in my car and tried to start it. The thing was that it wouldn't start. It cranked but no ignition. So I got a jump from some guy and still no luck. The Battery light and the Service Engine light is on. And another thing is my power windows still work when I take the key out of the ignition. Please Help...N-E-one! :mad:
  • niteman18091niteman18091 Member Posts: 8
    Replaced the Mass Air Flow sensor today. Very Costly and STILL does it. !!! Doesn't do it all the time, sporaticly, but it always happens when you really need to step on the gas in traffic, what now? How many sensors do I replace? This is baffling me as well as others. If the fuel pump is over heating, wouldn't that be dangerous being in the fuel tank? Plus, the fuel pump was replaced by the dealer 6 months ago. Please any help would be appreciated!!
  • repairdogrepairdog Member Posts: 948
    That was why I suggested clean it! Clean the EGR also. Most repair manuals list details on these and also coil testing. If the pump is 6 months old and a Delco doubt it could be that - fuel pressure test is required to be sure. Did you check all vac lines also for rot. If you keep getting O2 sensor codes there should be 3 of them - 1 in each exhaust in front of the cat and 1 behind it. There are many things that could be causing this . Have you looked at the injectors where they plug into the lower intake to see if they are not cracked or clogged - plastic squeeze connectors hold them in but this requires removing the upper black plastic intake to check which is not easy if never done before.
  • niteman18091niteman18091 Member Posts: 8
    I did have the injectors checked and even replaced the fuel pressure regulator . I checked the fuel pressure and it's KOEO 68lbs and with the engine idleing it'd 54lbs. which is within spec. I'm at wits end , the wife said if it's not fixed by weekend it's GONE, HELP, I LOVE THIS TRUCK!!! :cry:
  • 00blazer00blazer Member Posts: 2
    I have a 00 blazer with the 4.3L vortec. Driving home one night from work it just died on me. I got it towed to a local shop and the found it to be the ignition rotor spun off hte shaft and put a hole threw the cap. So once this was fixed I started noticing that the truck didn't want to start all to easily. I've tested power and vacum lines. I've found that its not holding fuel pressure when the car is off. Any ideas on how to fix and whats involved? Any help would be appriciated. Thank you in advance...
  • repairdogrepairdog Member Posts: 948
    Have you taken it to a Chevy dealer yet - once a local shop can't find it thats the next step - trying to find an intermittent problem is a pain - GM seen them all and Blazers have many.
  • repairdogrepairdog Member Posts: 948
    Standard fix is a new fuel pump assembly in the tank, or possible pressure regulator on the injection assembly under the upper intake. Have to test at port on fuel rail with a pressure tester and watch the pressure to see if its within specs then if it drops with the key off (key on engine off should be min of 60psi and running 54psi). As a test turn your key on, wait a few seconds and see if pressure builds then start - anything lower than 60psi (from the articles on this injection type) state that it will not be enough to fire all 6 injectors in a rich start state.
  • niteman18091niteman18091 Member Posts: 8
    The dealer put the new injectors and fuel pump in. I think I'm capable to change a SENSOR BUT THE DEALERS CODE READER SAYS THE SAME AS MINE. Maybe I should try another dealer???
    Changing the coil this morning.
  • samm00samm00 Member Posts: 6
    Did you solve this problem yet - our 01 is also stalling gen when the temp outside is hot - told the pressure in the fuel pump is good?? Any advice welcome???
  • niteman18091niteman18091 Member Posts: 8
    No it still does it. The other nite it did it and I again had to put it in Nuetral while moving and then restart and I had all the power I wanted. I can't figure it out and it's really frustrating!!! Any one with any help would be greatly appreciated
  • samm00samm00 Member Posts: 6
    We were told we have a Vapor lock - but they didnt know how to get rid of it?
  • niteman18091niteman18091 Member Posts: 8
    I was always under the understanding that fuel injection eliminated that problem. Now don't quote me on that but I'm 80% sure thats the case.
    Sounds like your emissions system isn't working properly or your fuel filter needs to be changed.
    Is your service engine lite on ? If so have your dealer or mechanic check your codes to see where the problem may lie
  • samm00samm00 Member Posts: 6
    This started after our 01 Blazer ran out of gas, now stalling happens on going down hill and seems to be in hot weather, the fuel guage is also inacurrate - any links - ideas - we also had intermittent O2 sensor codes in the winter?????? We had a new filter and the fuel pump has been checked!
  • ednedy07ednedy07 Member Posts: 2
    HOnda prelude cranks but wont start. Havent been driven for quite some time. Left parked in the summer heat.Worked for a while Drove for two days and shut off while driving.. Advice would be appreciated.
  • repairdogrepairdog Member Posts: 948
    If fuel pressure was 60psi key on engine off and then 53psi up running its OK. Possible crankshaft position sensor failing or back connection - under front of engine there is a plug in connector (under harmonic balancer /water pump area - you'll see if from underneath. They are magnetic and tell the computer when to fire the plugs - when they fully die no spark and no SES light so a pain - about $60 part held in by an 8mm bolt - easy to do. Cheap one to do and rules that out. Check coil wire also with ohm meter and make sure its OK and also no arcing to metal anywhere. Then the coil itslf should be tested if this continues.
  • repairdogrepairdog Member Posts: 948
    For your blazer model honda (ha ha): If you have spark then check the cold start injector with an ohm meter - if they are out of spec that baby will never fire up cold (additional one just for cold starts). Look resistance value up - no honda book here.
  • brian57brian57 Member Posts: 1
    :lemon: Got a 96 S10 Blazer 4.3 CPI. When stepping on the gas more than just a little bit the engine bogs and will die out and often pops threw the intake when it's doing this. It does this in park or under load. I bought a fuel pressure guage and at idle it's around 50. If I bring it up to a very fast idle it climbs to 55-60 PSI. Theres no engine light and no stored codes but the problem pursists. I can nurse it to highway speeds but at any steady speed it's surging. Filters been replaced but the old one was only a few months old. Also, it starts and idles perfectly. Truck has 176,000 miles on the original spark plugs. I wanted to pull the plugs but I can't even get my hand into where they are.... I'd love to meet the idiot that designed this thing...... Anyone have a cure to this sick truck ???? I can't afford dealer service rates ($100+) I also can't afford to throw parts at it until I hit the bad part...... :lemon:

  • repairdogrepairdog Member Posts: 948
    176k and you are complaining - that made me laugh!
    First things first is maintenance schedule and until that is up to date even the shop will insist on a few parts to eliminate reasons.
    1. Plugs, cap and rotor, plug wires, PCV (100k max miles) - most common reason for misfires, crossfires, bad running.
    2. Air and fuel filters (30k normal by conditions)

    After those there is the MAF sensor to spray clean, EGR possible carboned up, etc but do the above first. Plugs are easy to do thru the wheel well openings and only #3 has the steering shaft in the way and is a pain. Plug wires take awhile to snake around and don't pull hard on them and use dielectric grease in all ends and on drivers side watch order as its in cap 3-1-5 order (pass side is 2-4-6) and cap is marked - do not buy the cheapo stuff - if will fail - has on me and drives you crazy later. Cap has 2 torx screws holding on and you have to be careful and don't drop the screws in the dist! Rotor same thing.
    Hope that helps and good luck - 176k is great. How is the Coolant doing - 3 years should be changed and 4.3s are known to have leaking lower intake gaskets by 100k normally so watch the level - new thermostat and Stant cap with the flush change is recommended to keep it going - another forgotten thing till it has problems.
  • niteman18091niteman18091 Member Posts: 8
    I have the same vehicle and had exactly the same problem. After changing damn near every filter, sensor and believe me I wish I didn't, here it was the fuel pump. Even though it gave good pressure at idle and when you reved the motor in park, when it came to any movement it failed.
    This isn't to say new plugs and wires won't help, but trust me on this, it's the fuel pump!
  • 00blazer00blazer Member Posts: 2
    My guess is definately the plugs, wires and cap/rotor assembly. If you pull the front wheels off you should have no problem reaching the plugs except the #3. But it you jack up the engine a little with the floor jack it lifts it just enough to be able to get it over the stering column. Good luck.
  • preludeboy1preludeboy1 Member Posts: 3
    I would get a voltmeter or better still a scope on the O2 signal output. If it's an old/original sensor and not been replaced for 100K + miles then it will definitely be slow and likely causing havock with your computer trying to keep the emissions tight. I had an heated oxygen sensor go on me and just before the heater finally gave up the ghost it would bog down when accelerating. The ECU finally worked out the sensor was out of spec and pulled it open loop and the engine was driveable again. A new 02 sensor fixed the problem and cleared the "check Wallet Light". On a scope you should see a clean sine wave type waveform, going 800mv or more peak and 150mv or lower in the trough. The rise time should be 100msec or better. Without a scope, as a test you could disconnect your 02 sensor and see if the engine runs better in the situations you encounter the problem most. This might cause a little hunting at idle but the engine should run fine with the sensor out and effectively forcing an open loop feedback for the ECU. I'm guessing your ECU isn't quite seeing your O2 sensor so keeps in closed loop but it's just too slow. So in sudden changes of load or acceleration it's still reading the signal but it's just to slow and inaccurate to react, so it's throwing the mixture way too rich and then lean. Good luck!
  • kootzusakootzusa Member Posts: 1
    Hey Brian , I have the same problem you had .My 95 Blazer 4.3 W vin will start fine ,idles ok . When I try to drive it sputters and doesnt go over 2000rpm. Mine has 150k miles on it, the fuel pump is 4 months old ,the wires and plugs were done about 2 years did you fix yours?
  • delk1977delk1977 Member Posts: 1
    In October I bought a 2001 Chevy Blazer LS from a used car lot locally. Shortly after I purchased the vehicle I stopped at convenience store and turned the truck off. Upon returning the truck would not start. It would turn over fine but not start. I waited about 10 minutes and it started again. Then a couple weeks later I drove the vehicle from New York to Virginia. Once at my time share in VA I turned the truck off and a few minutes later the same thing, it wouldn’t start. I called the dealership and was told to disconnect the battery let it sit for a few moments and retry as it was a notorious problem with the anti-theft system. I did so, however, it did not immediately start. After about 20 minutes of sitting it did start.

    Since October I have had no problems with the vehicle until December 18th. I went outside in the morning and attempted to start the truck and like before, it wouldn’t start. It turned over ok but would not ignite. After waiting still no joy. I had the vehicle towed to the dealerships garage and was told it was the fuel pump and would cost $425.00 to repair.

    My issue is when I bought the truck it had the 60 day warrantee. I informed the dealer of this problem during the warrantee and was told it was a notorious problem with the anti-theft system and not to worry just to let it sit and it would start again. I told them this was the same problem as before and was told it wasn’t the fuel pump before because fuel pumps just don’t stop working then start working again.

    I called a reputable Chevy dealership and was told the anti-theft system would not allow the truck to turn over and that furthermore it was possible for the fuel pump to malfunction and then begin functioning again.

    My questions are...
    1. Do you think it was indeed the fuel pump that was prohibiting the truck from starting?
    2. Is it indeed possible for the pump to malfunction and then begin functioning again?

    I am paying for the repairs however; I intend to file a complaint with the NYS Attorney General regarding my warrantee not covering the repairs. Any insight anyone could give would be appreciated.
  • robertomusarobertomusa Member Posts: 1
    My starter went bad, when i was removing it i saw that it was only being held by one bolt instead of two. When i took it outi was able to see that the other bolt had been broken. I tried drilling out and jut made the whole thing worst. I piece from where the bolt is broke off, then i decided to drill a whole all the way to the other side to try holding it thighter, but now nothing works, what can i do!!!??? HELP PLEASE!!!
  • jtheifjtheif Member Posts: 4
    I having problems starting my truck in the cold it only happens when it gets cold. If I start it by crossing the starter it will start up (like touch the positive on the negitve nuts on the start it will start right up)other then that once i get it started and go some wherethen park shut off i have a problem restarting it it take several turns of the ignition before it starts back up. the starter i have is brand new maybe 2 months old the starter will click when the key is turned but the flywheel does not move till i cross the starter if anyone has any ideas it would be helpful
    Thanx Frustated Auto Guy
  • repairdogrepairdog Member Posts: 948
    When you turn the key to the spring loaded start position is 12v getting to the starter solenoid from the ign wire (samll one)? I've seen that nut get loose cause a pain to tighten up there.
  • jtheifjtheif Member Posts: 4
    i am going to try this when it get warm up here it is snowintoday so i will post the results in about 3 days thanks for the suggestion
    Thanks Frustrated Car Guy :shades:
  • captain67captain67 Member Posts: 3
    This 01 Blazer has a 4.3 ltr V-6, 150000 miles.
    It had been running just fine when one day I tried to start the vehicle and all it did was
    turn over and over. I put some fuel down the throttle body and it started and ran momentarily.
    I waited about a half hour and just for the hell of it I tried to start and vehicle again and it
    started and ran for two months without another incident.

    Once again 2 months later the same problem occurred and this time I took it to a dealer
    and they replaced the mass air flow sensor, fuel filter and fuel pump. Vehicle ran fine
    for 1 month but Friday, every time I stopped at a stop sign or tried to slow down to make
    a turn, the engine would stall. I would crank it over and over and it would start again
    but as I tried to get it back to the dealer the engine was starting harder each time
    ( meaning it would turn over and over more before it would start).

    About 6 miles from the dealer, the engine stalled and would not start again. After about
    20 minutes went by for some reason it fired up and has been running fine ever since.

    The dealer put their Tech 2 code reader on it and there was a code shown something about
    a loss of communication from the BCM but it had rechecked and passed sometime during the
    last 20 miles of driving. I have no service engine light on at the present time.
    Is my computer going bad?
    Does anyone have any ideas?
  • repairdogrepairdog Member Posts: 948
    Perhaps its the security system called Passlock that cuts fuel thinking someone is stealing it. BCM controlled and GM has the bulletin on the failure modes - usually a bad connector from the main wiring in the column. Does the security light come on when this happens - if so thats it. When it will not start does the security light stay on (should go out after apprx 5 sec when you turn to run).
  • captain67captain67 Member Posts: 3
    Ever since we purchased this vehicle, the security light has been intermitent. It comes
    on and goes off at will, usually when we are
    driving down the road. Would this connector cause the vehicle to stall when slowing down or stopping?
  • captain67captain67 Member Posts: 3
    If so what connecter am I looking for?
    Is this a part I can purchase somewhere
    or do I need to pull one from a junker?
  • crummydocrummydo Member Posts: 1
    Hello. I have an '01 Chevy Blazer and recently it has started having trouble firing up. It will crank over and take probably 10-20 tries before it starts up. ONce started, it runs fine. Put in the guage, and just sitting, fuel pressure dropped from 48 to 10 within two hours, so.. We did a tune up, replaced the fuel filter before deciding on the fuel pump. We put a brand new fuel pump in yesterday and now it is still having the exact same problem. Battery is brand new, too. Any suggestions?
  • sands53042sands53042 Member Posts: 3
    I have a 2000 Blazer that will not start. A couple of weeks ago on our way home, it just quit on us. It spit and sputtered once or twice and then just quit, like it was out of gas. We got it home, replaced the coil, had the module checked that is on the same bracket as the coil (it's fine), and checked the fuel pressure, which tested at 60psi with the key on, engine off. Can anyone tell me what I should check next? It turns over, but will not start. Any help would be greatly appreciated. Thanks in advance!
  • repairdogrepairdog Member Posts: 948
    Cap and rotor first to rule it out and get a Delco - had a few problems with aftermarket ones lately. That module is the ignition module (older blazers its in the distributor). Then next piece would be the crank sensor under the front of the engine right behind the harmonic balancer that tells the PCM where to fire the plugs (timing) and also get a Delco or Standard motor part. All fuses were checked of course.
  • repairdogrepairdog Member Posts: 948
    Any codes or SES light on? Fuel pressure should be min 60psi key on engine off - is it now? All fuses OK like ECM bat and ECM ign? Then cap and rotor if pressure OK cause maybe electrical. Then test the coil, and then the crank sensor.
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