trans87

I decided to take my TA yesterday to work instead of the GSX. Big mistake. I was driving on the freeway and then the car starting to blip. I thought it was odd. Minute later the car stalled then shot back to life. It was like I was letting off the gas then flooring it continously. I decided to get off the freeway and try to limp home. The car kept stalling then surge back to life. Finally the stalling got really bad where the car was complelely dead then came back then died. About 5 miles from house it just died. It would start with some effort and idle but as soon as gas was given it died. The whole time I could hear the fuel pump running so it was ok. The check engine light did come on while the car was still on but no codes were stored. I finally ended up getting the car towed back home. Anyone have any ideas on what's going on? I just put the Well's MAF in awhile back b/c the Bosch one was causing the car to buck. Do you think the Well's could be causing problems? Any help will be appreciated.

400Z28Racer

iTrader: (4)

never mind

sellmanb

by your description it sounds fuel related. I cant remember if you said that your car was TPI or Carb, but you should check the fuel pressure before the fuel filter, and after the fuel filter. If you have a carb then there's a in-carb filter that you may want to change out just incase, they're about 3 dollars, or atleast mine was.

By the decription it sounds like the fuel pump is shooting out fuel, but is clogged somewhere down the line... maybe a rubber fuel line got burnt through, or cracked or something and then you only got little blips of gas.

mrichar8

Mine did the same thing. The ignition module in the distributor cap went out. They can test it at Autozone or Advance Auto. Cheap fix if that is it.

Air_Adam

Sig says he has TPI. I'd check the fuel filter and the fuel pressure. Last summer, the same thing happened to my uncle's truck. He changed the fuel filter, and all was rosey again.

trans87

Thanks for the replies. The car is getting fuel it seems to be something in the ignition gone sour. The car will fire right up and idle but as soon as you start driving it begins its violent shaking which progresses into dying flat on its face. I'm going to change the fuel filter anyway just b/c it needs to be done but I think it's time for an overhaul on the ignition.

Bristol

iTrader: (1)

I had very similar problems. At idle or slow speeds no problems. Aggresive driving or higher sppeds it felt like I was turning the car on then off etc. FUEL pump is my guess. Slap a fuel pressure gauge and drive it

trans87

Yea the fuel pump is normal. When the car acts up it actually does shut down then start back up. Sometimes the dead power can last 10 secs or more before the car kicks back on. Eventually it will just keep permanently shutting off. No codes are thrown. Fuel delivery appears to be normal. I have a feeling it's something with the ignition. Either a bad pick-up coil or control module. I think is just time to go with a whole new distributor. The car still has the original distributor in it. Only thing ignition related that has been changed is plugs, wires, cap, and rotor. Everything else is what came on the car out the factory. Time for an overhaul.

sellmanb

if you crossed two wires, or ar arcing wires you could be experiencing this.

Go back through your firing order, and push the boots in all the way and make sure they "click" in. Could be a ignition module like stated above.

Air_Adam

Could be a very weak spark too. Maybe your cap or coil went south?

trans87

I checked yesterday to see if maybe a wire came loose off one of the plugs. It's happened before. Everything was snapped on tight and the ends of the spark plugs were screwed in all the way. I didn't notice any arcing. I've got my money on something in the distributor that's failing. The way the car falls flat on it's face it is completely different from the times a wire came loose or the time I put the wires in the wrong order. It's not bogging or low performance its flat out no performance and completely dying. Hopefully it will stop raining tom so I can crack open the cap and see how it's doing. I have had one of the tabs came off a cap one time causing a dead cylinder. The cap and rotor are a few months old but as stated before I have seen problems come up. I will also pull the module and get it tested at autozone. It checked out ok a few months back but being it's age I wouldn't be suprised if it went south. Hopefully I can get this solved soon. Even though I don't drive my TA everyday I still miss it I don't like when she's sick. Even though that seems to be half the time

har0xz

check the battery connection. there is a small wire that also connects to one of the terminals. i left this wire disconnected on my iroc and my car did the same thing.

rezinn

Sounds to me like a distributor problem as well. I've had an ignition module act that way before. Might want to consider that depending on how old your dist is or if it is a reman.

My car died on the 91 last week, narrowed it down about 90% to my fuel pump, which I can't change here myself. So I am looking at towing to Dons ($$$ for long tow) or having some unknown mechanic in the inland empire replace the pump.

If I were you I'd pick up an extra ignition module and swap yours out to see. Would be a good idea to check the coil as well. Just remember, new doesn't always mean that it works. I've learned that a few unfortunate times myself.

Hopefully we're both again soon

trans87

Well the cap and rotor look fine. I took the module down to Autozone and it checked out ok as well. However under the rotor the distributor looks pretty knarly. Lot of green corrosion around the connectors going to the module. I think it's time to just toss a whole new distributor in the car. Even if it doesn't fix the problem it needs to be done. Any recommendations on complete distributors?

BTW Rezinn I have been the same boat as you with a dead fuel pump before. I had Don swap mine out as well and just had him put a new LT1 fuel pump in. I had neither the know how, space, or tools to do the job properly so I had him do it.

black89ws6

I had the exact same problem with my car today.


I was out of gas.

Seriously, though, I would put a fuel pressure gauge on and see what you have. Just because you can hear the fuel pump, doesn't mean it's pumping, and it doesn't mean your fuel filter isn't plugged, especially since it will start and idle ok.

camzcruizer

i have a similar problem .....my car while at any speed will sometimes Check engine light pops on and car starts acting like its out of fuel so i pull over and shut it off or it will just die out
then ill wait a minute or two and she will usually start back up sometimes working fine or others stalling out again. it smells really bad when this happens like bad fuel any suggestions? fuel filter???????? i am thinking about changing it

86IROCTHD

i have had this same problem but i have replace the coil, pick up coil, ignition module and the knock sensor and retimed it many many times.... and i cant get it to go away... and i was messing with it today and it just died.... and now it will not start back up.... the check engine light doesnt even come on.... so i am lost now....

StaticVertigo

iTrader: (-1)

Not sure if anyone suggested this, Throttle position sensor.

if fuel if getting to the injectors under the proper prssure....and your ignition is fine....then something is telling your injectors not not deliver the fuel into the cylinders.

i HATE electronic problems that only happen under certain circumstances ..or every once in awhile......

MAF, MAP, TPS all could cause the car to suddenly surge without warning. there are ways to test these sensors with ease but this is a come and go problem, and what you, along with every other mechanic, will just be left to therorize and just replace parts that SEEM as though they may cause the problem.

trust me, i have a 4x4 foot box full of various sensors and such from my TBI days before i said screw it and went carb.

OR there could be a loose connection somwhere...and it only happens when constant vibration is present ... i.e. highway

trans87

I just got paid so I am going to be ordering the new distributor. While the car is down I am also replacing the fuel filter. After that we will see how the car acts. I am pretty sure it is something ignition related but we will see. I will also check on the TPS. I am keeping my fingers crossed that once the new distributor is in the problem goes away.

StaticVertigo

iTrader: (-1)

id try replacing the ignition module before replacing the whole distributor...start simple...coil....ignition module....make sure that your batt is good and its actually giving you enough juice to run the car corectly....same goes for the alt....both can be checked in the car at atutozone

rezinn

Hope that fixes it for you. An old distributor can cause some weird phantom problems sometimes. I swapped mine out for an MSD a few years ago and it fixed some problems I didn't even expect it to. Actually, someone stole my stock one when it was out, so I just had to go with msd :P

Going to have Don replace my fuel pump as soon as he is available. Going to be $$$ to tow it to him, but he's the only one I trust to touch my car.

trans87

All have been tested, all check out ok. Worst case scenario I have an updated ignition system. Hopefully the problem will get sorted out. If not then the hunt will continue. Thanks for all the help so far. I really appreciate it.

86IROCTHD

hey trans87 i just fixed my car that had a sim... problem... it was the ecm fuseable link by the battery... but my light was flashing and it would stumble alot.... with the light flashing... well there was a broken wire in the link and it was losing connection causing power loss to the ecm there fore no codes and the light was actually turn on when it got back power... so try to jiggle the wires with the car running and see if it dies... if it does replace the harnes with a fused link from like oreillys and install a 20 amp fuse... the replacement harness has yellow wires and its like a 14-12 gauge wire... its in the fuses section....this might not help u but its what fixed my problem.... so good luck... another help post up and i will see if i can help.... i have chaced this problem for like 6 months and just now fixed it so its a PITA .... but good luck

black89ws6

I doubt your distributor is the problem. Ignition problems are almost always an all-or-nothing problem.

You have said in several posts that "fuel delivery is normal" and "fuel pump runs fine", but how have you checked? Have you put a fuel pressure gauge on the car? What is it's pressure reading? Just guessing the fuel system is fine is a little like trying to fix it with your eyes closed.

I had similar symptoms in a v6 car a few years back, and it turned out to be the fuel pump. It still ran, but it only produced bout 15-16 psi, and wouldn't run with the throttle open much at all, so you see, it's possible for the fuel pump to fail, while still making running sounds.

I hope that helps some. When I get out to the garage today, I'll read through the troubleshooting charts in my helms manual. Those are usually good at pointing out possible problems.

trans87

****UPDATE***

Finally after accumulating parts everything has been installed. Put in a brand new complete GM distributor, new MSD Blaster Coil, new MSD 8.5mm Super Conductor wires, and a new fuel filter. Checked the fuel pressure and it stood at 45 PSI. The verdict:

Ok the non-starting was finally figured out and solved. The original distributor in the car was toast. The skins of the wires coming off the ignition module completely flaked away causing the wires to touch each other.

As far as the stumbling and dying part, the car still did it after everything was replaced. So we looked over everything and my buddy Rusty disconnected the IAC to see if that would do anything. Big difference. With the IAC disconnected the car no longer stumbled and died. There was still hesitation after starting off from idle but as far as what the car did before it didn't do it. I could drive around without the car violently stumbling then dying where before we disconnected I couldn't make it to the next street before the car would shut off. We plugged the IAC back in and the car was still acting fine but after driving for a bit you could start to feel it buck a little. Does this sound like an IAC problem? Anyone ever hear of this happening before? What is the IAC (if it is the problem) doing to cause this? I wasn't able to put an new one in because I just finished up tonight and its dark with the rain moving in. I am going to pick up a new IAC on my next day off. Do you guys think that might be my problem? Any other thoughts or ideas? After being able to drive my car today and having the little spark of it being back to normal I really miss it. I just want to find the problem so I can drive the car without being scared. Any help guys?

Red Devil

Still have the old MAF? Put it back in and swap out your relays. Send me the Wells.

trans87

LOL I have both the Bosch unit and the Well's unit. It acts up with either units.

trans87

What's the GM part number for my IAC? Is it
17112193 or is it 17111288? The 88 doesn't show up on gmpartsdirect but the 93 does and it looks like mine in the pic. Are those two part numbers the same unit or is there a difference?

camaronick91

focus your attention on the tps sensor. it altamitly controls the fuel and often because loose or broken. its a $60 part from napa and thats were i would go because all those other chains suck and i"ve gone to them all before and ended up getting the part at napa. you have to be careful with it because it can be broken easily. get a meter and adjust it to .60 volts.

oh yeah dont over tighten the bolts its just plastic and needs 18-20ft lbs

trans87

Thanks I will check into that. Probably pick up a new TPS with the IAC. Anyone have the GM part number for the IAC on my car? Any help will be appreciated.

1988 Massz

Hi just wanted to reply with extensive reading to your thread. Try just starting the car and let it idle and warm up and go into closed loop. I think you may want to replace the o2 sensor because it seams your problem is mostly at closed loop when the ecm is reading the o2 sensor and tps. Also in closed loop try disconnecting the maf sensor so it only reads the o2 and tps sensor and see if your stumbling is resolved. I have a question if you gutted the screens on your wells maf because this happened to me with the stumbling after a week or two the maf was showing way too much airflow and never through a code maf related. Yes if your iac is coked from the ccv then the pindle will seize and cause severe stumbling. Remove the Iac and clean the pintle with carb cleaner along with your TB. Then reset the iac with jumping your adl and leaving the ignition on for 30 seconds or more this will fully extend you iac. Also another point is look at the tps,iac,and maf terminals for corrosion and clean them if needed. Tim

trans87

The stumbling problem happens in both open and closed loop mode. I tried starting the car yesterday just to see how it would react one day later. It fires up but then starts surging and then dies. The day before it would idle smoothly but now it won't. It will smooth out if I give it some gas but if I just turn the key and let it be then it will surge then die. I didn't really get to mess with it much since it's pouring here right now. The Well's is unmodified but the car has the Bosch unit on right now. The car acts exactly the same with either the Bosch or Well's unit on it. This IAC is actually the 2nd one in a 6 month period. It's one of those crappy Well's one. The first Well's went out after 2 months or so and they replaced it with the one in the car now. The car has just never done what it's doing right now when an IAC went bad on it. That's why I was wondering if the symptoms on the car sound like they could be related to a malfunctioning IAC. I thought it was odd where it went from the car not being able to make it to the next street to being able to be driven around a city block as soon as the IAC was disconnected. I don't know if it did this b/c of a bad IAC or if by unplugging the IAC it cleared something else up as well:shrug: The O2 appears to be acting normal but I plan on taking a close look at the TPS so I will check the O2 at the same time. By the way thank you very much for the help. I really appreciate it, I really want to get this car back to normal.

***IMPORTANT***
I really need the correct part number for the IAC ASAP so I can get it. Does anyone know the GM part number for the IAC? I read 17111288 but it doesn't show up on any of the GM parts sites including cross referencing on AC Delco. Anyone know the difference between the 17111288 and the 17112193? Are they one in the same or are they different? I was thinking maybe a SD/MAF issue but I don't know. Someone please help me with this ASAP. Thanks and keep the suggestions on things to be checked on my car. I will keep responding to this post with progress until it is fixed so people that research later can get answers.

camaronick91

the reason for car running after u unplug iac, o2,or any other imporant senors to your computer. it will notice that and dump tons of fuel in because it has no idea if their unpluggedor boken. and it is designed to get u home to fix. when u talk about the surging it either the tps or maf . if i were putting an iac on my camaro i would go to nappa tell them the car and u will get the right quality part.GM. i belive all the iac for 305 or 350 are the same but not sure. if u messed with the maf screens and are to lean u can adjust the tps to dump for fuel in or out. good luck.

camaronick91

does the service engine light come on when it dies. Napa sells a computer for $20. it is best to check it right after the car dies. The iac regulates the amount of air bypassing the trottle body. It has over 250 different pintle postions. when you go 45 mph or above it resets it self. when the car is warmed up and u are idleing at a stop the iac should be closed but theres no way to check. it is an imporant part but have seen ones that were cracked and leaking air and all it did was a high idle in park. on the worse case the iac to be stuck and not moving it would possibly cause surging. if your engine light does come on it might be a transmission problem.(7oor4)

camaronick91

just thought if the cats are clogged u will have no performance and the car will die

1988 Massz

Another possibility to your dilemna and can mask many problems is the mat sensor itself. You can check the mat sensor though a little awkward via a voltmeter, just a possibility hope this helps

anondude13

How old are your fuel injectors? My car stopped having a surging idle and stalling after I got rid of the 95 LT1 injectors in it. Other than that I would say it's IAC/TPS or timing.

Red Devil

The relays were the important part of that post, not the MAFs.

Why are you going with the IAC and TPS? Adjust per the faq/tech articles. If you are that unsure, have someone datalog the thing. It will probably cost you less in the end.

trans87

I'm waiting on the datalog right now. Conflicting schedules and this never ending rain is making it hard to meet up and have the car run with the laptop connected. Only reason why I am really looking at the IAC is on how much of an affect disconnecting the IAC had on the car. It went back to normal other than a rough idle. Would pull hard on WOT and act like it's usual self. Although I have never heard of the IAC causing symptoms that I originally posted. Fuel injectors are stock L98 injectors and the car doesn't have a cat so no problems there. Hopefully this rain will let up some so I can go back outside and test the voltage on the TPS. I wil pull the IAC as well and see how the pintle is looking. These damn Well's ones are POS. The last one just completely froze so the car wouldn't idle at all. I will try starting the car again and see how it's doing. Timing was just reset due to the distributor swap. This rain is killing me because it's stopping me from doing any work on the car at all.

trans87

Well the car was datalogged today. TPS, IAC, 02, etc are all working normally. The chip in the car did crap out at the end but that wasn't the problem since the car still had the hiccuping with a stock 88 350 chip in the car. We did notice however the car was running extremely lean when above idle. At idle the car was optimal but as soon as it started warming up and was moving it became increasingly lean. With the stock 88 chip the car ran rich. The knock count was low as well. So right now we are sending the data to someone that might be able to shed some light because I am stumped right now. Running out of things to look at right now that can be causing this sudden stumbling and stalling when driving. This is very confusing and disheartening. Hopefully the problem can be resolved soon.

razor

Have you ever checked the relays?? If you haven't just unplug the MAF and then start the car. If the car has the same stumble then you know it has nothing to do with the MAF system. One less headache you have to worry about. Then go check the resistance on each injector with a multimeter. They all should be in the 16ohm range. If you find one way out to lunch down below 12 then post those results. A reading below 12 when the injector is hot will signify that the injector is internally shorting out and is fubar

trans87

I think I might have found the problem. I finally got a chance to ohm test the injectors and here are the results:

Driver's side bank;

Cylinder #1 - 17.5
Cylinder #3 - 3.5 <----- Check out that
Cylinder #5 - 16.9
Cylinder #7 - 17.0

Passenger's side bank;

Cylinder #2 - 17.1
Cylinder #4 - 17.3
Cylinder #6 - 16.9
Cylinder #8 - 5.9 <----- Not one but two bad ones

Looks like two of the damn multecs crapped out. Most likely are shorting out when they get hot which is causing the car to stall out. Looks like it's time for the some nice Bosch injectors off 5.0 motorsports. So what do you think guys, think I found the problem? Let me know your thoughts and thank you very much for the help so far. I think I am getting closer to getting my car back.