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GMC Safari/Chevy Astro Starting/Stalling/Idling Problems

124

Comments

  • wkmyastrooffwkmyastrooff Member Posts: 2
    Reply for the 1996 Safari with the spuuter and misfire. When I was originally troublshooting my no start problem I suspected the engine control computer... I think it's call the ECM on the wire diagram. Anyway I was referred to an experienced mechanic that did exactly what you did. (We're talking about the module below the brake master cylinder with 4 cannon plugs coming off towards the front of the vehicle...just making sure) The mechanic took a ball peen hammer and hit the ECM while I had the van running. Since the van didn't skip a beat we ruled out the ECM as my problem. He did however tell me that this was a problem for vehicles with your year model and what you did was the test for that defect. I guess what happens is that a crack develops in the circuit board inside the unit and then when it gets hot/cold, hot/cold etc etc it starts to cause issues like what you describe. You should be able to pick up an unprogrammed ECM at your local parts place. You'll have to take the little panel off the side of your old ECM so you can retrieve the knock sensor for your new computer. Of course you'll have to have the new one programmed which should cost around $80. Unless you know someone personally at the dealership to help you I wouldn't even go near there with this problem. Good luck. By the way, I'm told the van won't run without it being programmed.
  • bwgmcvanbwgmcvan Member Posts: 10
    started again today- this only is happening when it snows outside and the the streets become slushy - never when it rains and never when it's just cold outside- without snow--- this is driving me insane, I drove over to my GF's last night and started misfiring again , then I backed it into her driveway and it really got worse and then died- I was able to restart it after it died, let it run for a few minuits and then when I steped on the gas pedal it went to full throttle , but before this I would give it gas and start to misfire and buck off and on- I really need some help on this one - do any of you have or had the same problem- writing while i am trying to start the van,,,I stuch a hair dryer in the cavity near the coil--? guess what it started,could the moisture in the air from wet heavy snow be causing problems with the coil????need some help
    thank you
  • pinky6pinky6 Member Posts: 3
    We have a 1999 Astro Van and it stalls out/then won't start in wet weather. The distributor cap coilwire plug wires fuel pump and relay have all been replaced still stalling out, any ideas?
  • 94astroext94astroext Member Posts: 3
    Hello, my 94 astro will just shut off as im driving or even stopped at a light. I replaced the ignition mod,coil,cap,rotor, plugs and wires but its still stalling. any help with this issue would help me greatly. thank you :sick:
  • Steve_01Steve_01 Member Posts: 42
    Any codes? OEM or aftermarket cap and wires? This engine uses a very high voltage coil/spark/ignition. Low quality ignition components will allow the spark to 'leak' or short out easily.

    You might also want to check the fuel pressure. Don't know about the 94, but on my 97 the fuel connector is just left of the distributor cap. Look up the spec's for 94. 97 fuel pressure is around 58-63 psi. You can probably rent a pressure gauge for little to no cost.

    I've seen posts in this forum indicating that the bulkhead connector (behind the battery) has 'melted' and/or folks have found corroded connections causing the symptom you described.
  • 94astroext94astroext Member Posts: 3
    No codes, Im not sure about the cap and wires I've had the van for a month now. it will start right up aprox 2 min after stalling . Im thinking of replaceing the fuel pump assembly as my next step but I will check the fuel pressure before I dive in. thanx
  • alberta4alberta4 Member Posts: 4
    I have a 97 Safari RWD with 200K kilometers on it. I am having real problems with hesitation. It has been going on for about 3 years. At first it only happened in the spring but it has been getting consistently worse. The hesitation happens when I step on the accelerator the van seems to die and then lurch forward in a stuttering kind of jerky way. Once I get to higher speeds it is ok. If I do not drive the van for a few days it gets worse. After I drive around for 20 minutes or more the problem seems to resolve itself. If I drive everyday, it is not as bad. It is the at its worst in the spring (I do not have a heated garage and it gets really cold in Edmonton). It is not throwing any codes and I have brought the car in a number of times and my mechanic can't find anything wrong. I specifically asked him to check the distributor, coil and spark plug wires (because moisture seems to make it act up). I am starting to have doubts about my mechanic. I am thinking it may be a dirty throttle body or a bad TPS. I have doubts about an O2 sensor causing this type of problem with no codes (but I am not a mechanic). I would really appreciate any advice that anyone might have regarding this problem.
  • bwgmcvanbwgmcvan Member Posts: 10
    bulk head connector,, that sounds like that could be the problem- 2 months ago it was snowing out, slushy,, started sputtering and jerking then died- I pulled over , banged that area and it started up, also when I was driving home it started again, pulled over, sat for 5 minutes , pulled off and started on my way home- I had to pull off the road 5 times until it ironed itself out and ran smooth. This only happens when it's snowing?? any thoughts- also my service engine light goes on for a few days then shuts off- constantly- any thoughts
    Brian
  • Steve_01Steve_01 Member Posts: 42
    edited March 2010
    Don't forget about the fuel filter, could be clogged.
    In case you don't have a repair manual here's some quick specs for you. According to my manual, the CMFI (Central Multiport Fuel Injection) system is used on all 4.3L V6 VIN W engines manufactured from 92 to 95. In 96 they switched over to the CSFI system. The CMFI system uses a single central fuel injector which feeds each cylinder through six separate tubes and poppit nozzles. The fuel pressure regulator is mounted directly on the fuel injection unit.

    Fuel pressure:
    Key ON, engine OFF - 58-64 psi
    Engine running at idle - Pressure should DECREASE by 3 to 10 psi

    Remember that low fuel pressure, does not necessarily indicate a bad fuel pump. It could indicate a bad fuel pressure regulator. In the 96 and up (CSFI) systems, it's not uncommon for the regulator to leak inside the intake manifold. A leaky regulator could lower your fuel pressure and make the engine run crappy, not to mention fuel could leak down the inside of the engine into the oil pan. Not good.
  • Steve_01Steve_01 Member Posts: 42
    The only way to know for sure is to pull the battery out and disassemble the bulkhead connector. I haven't had to do that on mine but I did pop the cover off while I was replacing a dead battery a few months ago. It looks like there's a bolt (maybe 10mm?) in the middle of the connector holding it tightly in place. It's worth a look.

    If you go to your local large chain auto parts store, they will usually check the codes for you for no charge. The check engine light doesn't necessarily have to be on. The computer will store the code(s) for a while but it would probably be better to have it checked while the light is on just in case.

    My Astro has had the light come on once or twice and go away on its own. I know for a fact that it has intermittently low compression in cylinder #1. Probably a sticky valve. The only time the light has come on is when it's sat for a week or so without driving.

    If you have a P0300 code, that's a random misfire. P0301 = cylinder 1 misfire, P0302 = cylinder 2 misfire. And so on, you get the idea.

    Hope that helps.
  • cascade159cascade159 Member Posts: 2
    I had a similar problem with a 94 Bravada. Turned out the CMFI connector on the plentum had a slightly bent pin. I had to replace the harness inside the plentum. If you touched the connecter with the car running, it would cause it to stop.
  • cascade159cascade159 Member Posts: 2
    I have been chasing this problem for a while now and thought I had it solved. The van has a rough idle and wants to hunt for the correct idle speed. The main symptom is on accelerating from a stop where if feels like half the cylinders cut out. Today, sitting in the driveway with the van in park, I accelerated to about half throttle when it started cutting out. With my scan tool hooked up, I see the S-T fuel trim drop to the mid 80s. I can also see IPW fluctuate from 7 to 0. At times it is steady at 2 with the van running smoothly. Since there are so many input that can control the IPW, I am at a loss as to where to look.

    The van has new fuel filter, plugs, wires, cap, rotor, EGR valve (repeated DTC 32) and O2 Sensor. The van has 186k on the odometer with 150k on the engine. Fuel pressure also checks out, the spider is not that old and holds pressure well. There are no other codes.
  • 94astroext94astroext Member Posts: 3
    ok, so I took off the engine cover so that I might be able to diagnose the problem when it happens. it didn't shut off for two days so I thought that the cover might have something to do with it. I re routed the ignition wires so that they are away from the heat shield of the cover and put the cover back on. this was three days ago and still going strong without a problem.
  • Steve_01Steve_01 Member Posts: 42
    On that note, years ago I had a similar problem with my 97 Astro running rough and not starting. It turned out to be the coil wire shorting out against the transmission fluid dipstick tube. If I look closely at the tube, I can see where the high voltage arcing has slightly eaten away at the metal. I wrapped the tube with the same type of foam insulation used to insulate the hot water pipes in the basement. That took care of the problem.
  • irish_johnirish_john Member Posts: 2
    Hi all, I'm a new kid on the block, Just joined today............. What I would like to know is if any you guys out there be so kind as to give me some advice about my 1995 GMC Safari?
    I found her running very bad with regards power, she would take off ok but after she change into top gear she seems to lack in power, and also I have notice like a rattle or a kinda chain type noise when I go to excelerate with my foot right down on throttle ? As a result I am scared to push her to hard in case I cause more problems. I have just change the oil on her and put new oil filter on and also changed the trans fluid and put new air filter in, but till she is not running well at all, So at the weekend I got me mate to fit a new fuel filter on her hopeing that this will sort it out, but again she is just the same lacking in power???...............
    So do any you guys have any idea as to what could be my problem with her?
    I live in Belfast, Northern Ireland, and I get all my parts from a dealer in England, so I hope its not going to cost me the earth to fix :cry:
    Thanks so much for you time in reading this :cry: for help!
    John, Belfast, Ireland.
  • bwgmcvanbwgmcvan Member Posts: 10
    DId you check to see if your catalitic converter is clogged?
    Brian,NY
  • irish_johnirish_john Member Posts: 2
    Hi mate, thanks for ur reply, Ihave not checked the cat converter? how do i go about doing this???
    Please help!
    Johnny. :sick:
  • bwgmcvanbwgmcvan Member Posts: 10
    Check it night, see if it is glowing "red hot" this is an indication that you have a clogged Cat converter,, builds up with carbon, that is one way, look on the net and see if you can't come up with some way of deciphering how to check the cat converter

    keep us posted mate,
    Brian
  • russ75707russ75707 Member Posts: 7
    edited June 2010
    I have a 1995 Astro,4.3l z ,cmfi.I have had a problem with the van idling rough at stoplights,but when shifted into Park or Neutral the damn thing runs smooth as can be.In an ongoing attempt to find and fix this problem,(i have 250,000 +)I have never eliminated problem by cleaning egr,iac,etc,fuel pump went amid all this,of course,I caught this one b4 I got stranded yessss,replaced pump,filter,thorough carbon cleaning,tune up,ran sea foam through everything,nothing has made a difference.I wonder if the torque converter really is sticking?Thedistributor shaft feels sturdy,but whadda I know,how can I rule that out?Is the best way to rule out sensors is to unplug them one byone?I have yet to get a code other than 12 from pins on obdm-wan (whatever its called) connector.i'm starting to get pissed now,I broke knock sensor and temp sensor thing trying to reach through beside motor,had to rig those back after I identified them.Now what?Anyone.....anyone......anyone at all.....No,I will not burn it!!Shameful thoughts,does anyone have any ideas that might help me locate and stomp the s**t out of this meddlesome problem for good?Cat converter is cleaned out too
  • bwgmcvanbwgmcvan Member Posts: 10
    Russ,
    Check you wires/coil/plugs- there could be carbon build up in the cap,, or wires that are not shielding the spark and arcing.
    Brian
  • GuildmanGuildman Member Posts: 6
    I know this issue has been addressed but I don't know what to try next.94 Astro 162k starts to idle rough at stops and stalls with more frequency at stop lites,only after car is warmed up.Have removed and cleaned egr,Noticed egr valve was not moving freely,after cleaning problem still there.Valve did not stick when fully depressed to solinoid in egr.Is that a sign it needs to be replaced?Whats the most likely next problem to check? No check engine lite comes on.Mechanic checked dist cap, plugs,wires,and said they were all good.He didn't want to start throwing parts and money at it cause there are are to many possible causes.Saw someone had a fix with vacuum hose & elbow at pcv.Could it also be the IAC?Have new tires and so many new parts I hate to give up,everything else is running great.Any help is greatly appreciated
  • GuildmanGuildman Member Posts: 6
    Can't edit message so I'll add to it.As with Russ post previously,when I shift to neutral or park at a light problem problem dissipates or mostly gone.4.3 llter cmfi w engine.No hesitation or misfire when driving,only at idle after engine heats,and problem is intermittent.
  • graylinergrayliner Member Posts: 39
    Not sure, but since you're ok when out of gear I'm wondering about the mysterious Throttle Valve cable -maybe line pressure is off due to electrical/solenoid? It connects the throttle body to the tranny and is full of voodoo. Might want to track down an experienced/trained GM transmission shop to road test diagnose it. There's a science to it. Check the lockup torque converter clutch solenoid. They can stick when hot.

    I had trouble with my distributor, timing on a '97. I replaced the timing chain, while in there checked to see that my crankshaft sprocket dot was lined up with my camshaft sprocket dot so my timing could be set. The #4 cyl will be at Top Dead Center now. And the rotor in the distributor will need to be facing the #4 terminal in the distributor cap.

    Put a new crank position sensor on (if yours has one) because this can cause issues. The timing chain is a good thing to do just as wise general maintenance anyway. Don't want mine to grenade on me anyway. But I don't really think it's a timing/distributor issue. I suspect a tranny-electrical issue.

    Hmmm... let us know what you find please.
  • russ75707russ75707 Member Posts: 7
    The clutch lockup solenoid idea sounds entirely plausible,anybody know where it's at on Astro's? I can test a solenoid,all they are is a contact that becomes magnetized when energized,and creates a circuit.I have a two wire connection @ the rear driver's side of tranny that I thought was speed sensor.The connection has been badly fouled w oil for a while and I cleaned it thoroughly several times ...it appears to be clean and dry at last look though
  • GuildmanGuildman Member Posts: 6
    With further checks on other forums,I think you're right about it being the TCC solenoid.Other symptoms-after exiting freeway to a stop I hear a clunk almost like I've been rear ended-maybe thats the lockup not releasing from overdrive.The engine misses intermittently at idle in park as well,but that could be another problem.Trouble is,all these things are inconsistent so I can't reproduce them at the shop.The solenoid fix looks like it might be beyond the average diyer.Is it? Thanks for the help
  • russ75707russ75707 Member Posts: 7
    Where is it?Anyone tell me where it is I'd like to take a look at it,maybe i'll check autozone repair manuals
  • GuildmanGuildman Member Posts: 6
    Unbelievably,all my rough idle, stalling at lights and after coming to stops at freeway exits,seems to be solved by one treatment of Techron fuel system cleaner!Hard to believe cause all symptoms were pointing towards Tcc solenoid.I'm reading ethanol mix in California gas,especially cheaper brands, will clog fuel injectors over time.If this fix holds its the best $9.00 I've ever spent.I'll throw in another bottle for good measure on the next fill up.
  • russ75707russ75707 Member Posts: 7
    edited August 2011
    I have read exhaustively night after night,scouring the automotive forums,picking up some pretty impressive viruses from some of them,cleaned egr 5 times,changed fuel pump #4 for me,broke knock sensor and cts sensor on drivers side btwn #3 and #2,tuned up,changed rear end,rear u-joint twice,changed oil a coupla eimes,fixed ac,then broke it ***** w it like a *******. All while trying to find out if spyder needs replacing or not,and why rough idle when stopped but clears immediatly when put in
    park or nuetral,damnit i even went to clean out cat converter and found out it had all blown back into my late model muffler and ruined it.UR NOT GETTING OFF THAT EASY!! LOL another cause I've investigated is possible loose/worn distributer shaft bearings
  • GuildmanGuildman Member Posts: 6
    Believe me,I know its to good to be true.I feel your pain,& I'm gonna assume you did the fuel additive (twice?) with no results.I also did a couple of small things for what its worth.Sprayed carb cleaner around all the vacuum lines,making sure they were all intact,especially at the ends and where they lie close to engine block& get to much heat.Also cleaned pcv and checked elbow at pcv valve.Let you know if my fix holds,or maybe I'll just park it so I can claim victory over this beast,ha,ha
  • russ75707russ75707 Member Posts: 7
    I hear u about parking it,wanna quit on a high note!I only know of maybe 4 vacumn lines all good,I visually inspected pcv elbow,half assed,maybe that warrents a second look,I try to schedule doghouse/engine cover removal when I have a whole day of work there,cause inevitably i get done and am too tired to put it back right,and @ 260,000 miles and 15 yrs of age,if u dont stay on top of the little things,it turns into a junky piece of crap pretty fast.I guess tcc solonoids are inside housing of tranny,so I will need to plan that in advance,A lot of cursing,tool throwing,and etc. goes on then...
  • GuildmanGuildman Member Posts: 6
    Stalled once yesterday after decelerating from about 45mph,but I will say my normal idle is much better than before fuel treatment.Here's a link & info on Gm tcc solenoid replacement.He talks about checking engine problems and the tcc linkage first,before doing the solenoid replace.I'm pretty sure mine needs the solenoid -there's GM tsb's on it apparently.
    http://autorepair.about.com/cs/doityourself/l/aa011703b.htm
    Let me know if you manage the repair-its past the mess level I want to deal with.">link title
  • spfldospfldo Member Posts: 1
    I had a 94 astro, bought new. It had the central port fuel injector. First thing I noticed was that it had a misfire once in a while and took longer than normal to start. This went on for quite a while and I thought I'd get around to tuning it up. Then one day I about ran the battery down trying to get it started. I drove home, parked it and was going to do a tune up, but then it wouldn't start at all. The only thing I could find wrong was fuel pressure. If I remember the manual called for give or take 54lbs. pressure. My reading was 48-50. I thought surely that wouldn't keep it from starting - but it did. New fuel pump and drove it many thousands of miles more. My brother had a no start in his '99 and it was a dist. cap. I also had a 99 that Ibought new. At 24,000 miles it developed a mis-fire. I can't remember the code (p301 maybe) - random intermittant misfire and it acted just like a plug wire was bad. Took it to the dealer they did an injector clean -twice, a top engine clean and a new fuel pump but they never fixed it. I took it back again and they washed their hands of it - GM was no help and they wonder why I never bought another GM product? After driving it another 125,000 miles with this stupid problem I never did get it figured out exactly. Sometimes it was worse (terrible) than others and sometimes drove perfectly. In later years it would always show up on damp, rainy / cold mornings. I'm sure it was a secondary ignition problem but I'd replaced wires, plugs cap, rotor, module, coil and EGR valve. I'm sure it is something simple that is apparently common and it really pisses me off that GM wasn't interested in finding out what the problem was. I came to the conclusion that the "flat" dist. cap is poorly engineered and even a new one might not work. I tried original equipment, aftermarket and a JEGS cap with bronze contacts, but nothing worked. I was at the parts counter at the Chevy garage once and the guy in front of me was trying to buy a cap for his Astro. Parts guy says that's funny we're out of stock - we've already sold three this week. I also had a similar problem on my Suburban - one time a bad misfire (so bad I thought the timing belt had jumped a tooth) and the other a no start. It ran perfectly when it was pulled into the garage but wouldn't start next morning. I'd had a friend with the same problem in a half ton Chevy pickup so I knew to replace the cap and the problem dissapeared. Hope that gives some insight
  • papasmurfnogopapasmurfnogo Member Posts: 1
    My Papa Smurf (Astro Van) was backfiring, staling at start up & stops, and had a squeak up in the engine. Then he just lost power, went into limp mode, wont accelerate more than 15-20mph in drive, no more backfire, not much squeak, and now when he stales I smell gas; like its flooding while driving!...He leaks tranny fluid....hmmmm? Any suggestions on where to start on this project?
  • wildfire2wildfire2 Member Posts: 1
    One time ours did this - was a bad ignition coil.
  • rutrowreorgerutrowreorge Member Posts: 1
    My 2000 Astro has a wierd problem I have not seen here. It will start right up, even in sub freezing weather, but only if I start it every day. Let it sit for a day and it is difficult or won't start and then it chugs and spits for the first few miles. It doesn't seem to be a fuel delivery problem because it won't even start using ether starting fluid.
  • gzilla5gzilla5 Member Posts: 2
    I"ve wrestled with this problem for about a year now. I've replaced the plugs, wires, tps sensor,
    distributor cap, rotor, distributor gear, and fuel pump. I bought the fuel pump online and it turned out to be a piece of crap. Too bad I threw the old one out it turns out there was nothing wrong with it. I had the hesitation problem which the distributor gear fixed. When I removed the distributor to change the gear i marked it so as to not mess up the timing but when i went to put it back in I noticed the marks I made wouldn't line up. I suppose that worn gear threw the timing slightly off because now it runs fine when it starts. Now as for the not starting in humid or rainy weather problem the trick is to remove the distributor cap and cover the screws holding the rotor down with some silicone. After doing the latest round of troubleshooting i noticed spark from the coil wire but no spark out of the cap to the plugs. I removed the cap again and i noticed some arc marks on the screws holding the rotor down so i screwed it down tightly and topped off the screws with some silicone. It's been raining for a few days here in San Diego and i have not had that problem again. In short new distributor gear equals no hesitation, more power and better gas mileage. Silicone on rotor screws equals starts. Hope this helps you.
  • chevykid1chevykid1 Member Posts: 1
    what cap gas cap distriburator cap?
  • gzilla5gzilla5 Member Posts: 2
    I posted my fix for the no start problem on my van about ten days ago and even though it's been raining a bit down here i haven't had a problem since. i believe that in rainy/humid weather there is a build up of humidity in the distributor cap. This causes the spark to take the easier path to ground through the rotor screws. This is why the problem always seems to be fixed after replacing the cap and/or rotor only to return again. With the distributor cap removed locate the two screws holding the rotor down. Apply enough silicone to the screw heads to thoroughly cover them. Give it time to dry. It shouldn't take long. Now reinstall the distributor cap and wires. I hope this works for you. Please post if it does. Thanks.
  • bwgmcvanbwgmcvan Member Posts: 10
    it was the ignition coil, the van ran fine after the installation. I sold the van earlier this year , she didn't owe me a dime and served me well.

    thanks for the helpful information, I really appreciated the input,

    B,
  • kingoftkokingoftko Member Posts: 1
    I bough an 89 astro van from a friend back in august. Its a 6 cylinder and it was sitting in his yard for about 2 years. I replaced the battery and altenator and off i went. In october the van wouldnt start for like 20 mins, would turn over with the starter but that was it. Then the problem got worse. Instead of just not starting now it will cut off mid drive suddenly with no warning whether im accelerating or not. I get no sputtering or anything. The only reason i know its off is when i push the gas pedal and get nothing hahaha. This is really scary when your doing 40 miles per hour!!!! And then i cant get it to start again for a while and even if i do get it started it can do it all over again right away or wait a month to happen again.
    Ive replaced the plugs, wires, altenator, battery, entire distributor spindle (cap, module, rotor)
    I know he replaced the fuel pump and egr valve before he parked in his yard 2 years ago, and he also had a bunch of other work done. A buddy of mine is trying to trouble shoot and said that maybe the TCC sensor or something can be making this happen.

    Any ideas are greatly appreciated :D
  • needhelpinpaneedhelpinpa Member Posts: 9
    OK, This may be a long shot but my 94 would die suddenly or not even start. Upon investigating I also had no headlights and heard no fuel pump start up noise when I turned the key. Turns out part of my fuse panel was not getting juice. Why? Because on the astro behind the battery is a main wire plug connector that goes bad and can send juice through 1,2,or3 of the 4 wires. I found which one, hot wired it and I'm good to go. Just a possibility for you maybe.
    Ted
  • needhelpinpaneedhelpinpa Member Posts: 9
    94 awd astro. Makes a noise in tranny like something rubbing on flywheel. Nothing, all seems clear. Tranny dies a year later and the noise is right there from the beginning even with a different tranny. Mechanic baffled. Any suggestions? Thank you.
  • ccherdrem43701ccherdrem43701 Member Posts: 1
    OK I have a 2000 GMC Safari Van and I am having problems, Recently had problems with starting so we changed the fuel pump but it only ran for about 14 days, now it won't start again, Any suggestions? Desperate to get this fixed.
  • edonaldsonedonaldson Member Posts: 1
    This has been a problem for me now for over 4 years. I have been told that it is a problem with distributor placement and overheating causes small cracks in the cap and that it means replacing every year?Mechanic Friend just told me that it is probably the wrong distributor and he will check the model in my van (he is a GMC mechanic) -In the meantime I will try your fix-thanks
  • swiftone559swiftone559 Member Posts: 1
    MY ASTRO WONT START CRANKS OVER ,REPLACED IGNITION COIL,DIST CAP AND ROTOR,WIRES AND PLUGS I HAVE A VIDEO ON YOUTUBE SWIFTONE559 IS MY CHANNEL ANYONE PLZ HELP
  • sephknightsephknight Member Posts: 2
  • sephknightsephknight Member Posts: 2
    Hi I need your help experts of Gmc's. I have a *94 gmc safari sl 4.3 v6 mini van. Only 71k + miles by the way ill sell it for 1,500 as is. It's having acceleration problems. Basically it all started when someone changed my water pump. I know it has nothing to do with it but recently someone told me there is a sensor behind it that regulates all sensors and if dirty can lag acceleration. Anyhow here's the issue when the car accelerates from 0 to 40 or more it lags and is no accelerating properly. I have to keep pushing the pedal tapping it faster and faster to accelerate it. This comes and goes meaning sometimes it is normal but more often than not its lagging. When i turn off the car quick and turn it on it goes away but the acceleration is hardly the same as it used to be anyways and accelerates slower than normal. Once in a blue moon it goes back to normal the way it used to be. Someone told me because when i turn it off and turn it on and it accelerates almost normal to normal sometimes that it has to do with the oxygen. Now im not a car expert but here's what ive tried and figured it could be been trying for months now. Had the fuel filter changed not it, had the fuel pressure checked not it, Fuel pump not it, catalytic not it. The mechanic who changed the pump said it was something oxygen related now how would he know that? I think he sabotaged it to get more money from me i haven't spoken to him since he disappeared. I think its either the throttle body part or whole thing spiders ect. Or its a bad wire somewhere its a pain to find i hope not. Or its the o2 sensor let me explain. I had a diagnostic with an obd1 sensor. The corporate office from GMC after many calls and hit a wall with an evil woman who thinks i wont find the upper vp's numbers i will eventually or if someone has it they are located in Detroit michigan has impeeded my progress for answers but according to them and others it doesn't have many sensors. Doesn't have a map sensor but im not sure about that. The obd1 test from someone who had the old red machine obd1 where years before 96 car parts compatible from 91 to 94 only i believe that's what corporate said not anything after 95. Anyhow the obd1 test said it was either the catalytic, fuel filter, or o2 sensor. So far the only thing i haven't changed or checked is the o2 sensor will do that this week finally been busy doing other things. someone told me on rare occasions the o2 sensor rd cause acceleration problems. several mechanics said no but we will see. At this point any suggestions would help. Oh yes an my other theory is that its the computer. I had it changed a year prior after a questionable mechanic shop told me i needed it after battery died. Found out later after battery died how cheap and easy it is to change only 100 bucks or less and its plug and play. Was charged 400 bucks. Went back for warranty the guy said he lost my records. Will consult lawyer i think that's illegal he must pay but anways don't worry ill rate him badly on Angies list and every other mechanic who hasn't found the problem! Anyhelp would be greatly appreciated. Im going to try to post this in as many sites as possible. Ill keep you guys updated on my o2 sensor change. Don't want to spend too much money on this otherwise i would have changed all my theories already. wb asap and please logical helpful replies and if you don't really know don't answer its already confusing enough.
  • thermsdavethermsdave Member Posts: 2
    I had severe driveability problems with my '95 Safari (245,000 mi.) and replaced the intake air temp sensor, a split elbow at PCV valve, the EGR valve due to a completely open feedback loop coil, and a canister purge solenoid that leaked vacuum. I had a big improvement with the first, small improvements with the other three. The nagging problem that wouldn't go away was the lack of power at high speeds, slight roughness at all speeds, and exhaust manifolds that glowed orange hot when driven at night w/engine cover off.

    Replacing the distributor with a $100 rebuilt unit from Advance Auto Parts has it running like it has never run for me. Other symptoms: Slight side to side movement of the distributor shaft, a corresponding wear mark in the cap that is 2-1/2 times the diameter of the contact on the rotor. A vibrating oil pressue needle.

    This thing now performs well under all conditions and has never before been this smooth.
  • thermsdavethermsdave Member Posts: 2
    I should add that the giveaway that it was a timing issue was hooking up a timing light (even though the computer sets the timing automatically) and noticing that the timing jumped around constantly.
  • lmmaralmmara Member Posts: 6
    Hi,

    I have been having the exact same problem with my '00 Safari. Have you ever resolved this issue? If so how?

    Thank you,
    Leo
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