'88 350 TPI IROC. Used hard in a previous life, and slowly coming back to life.

The problem I've had (and thank you to those of you who have been kind enough to help previously) is that I'll be driving along, and it will suddenly stall. No error codes, just stops running. There's no bucking or hesitating, like when you run out of gas, it just stops running, and I have to pull over. Usually will restart after a couple of seconds, but sometimes takes several minutes. I've replaced the fuel pump (what fun!) and fuel filter, and have previously swapped the distrib cap and wires.

What do you all think - Ignition or gas?

I'm leaning toward ignition, because of the way it stalls (no hesitation, or hiccups - just spins down!). Ignition module? Distributor? Computer? A relay somewhere?

I like the car, but this is MOST frustarting...

 

Sounds like an ignition module problem to me. I see that pretty often at work. Have you pulled a wire and checked for spark? Do that the next time the problem occurs.

 

I'll second the ignition module. Although they normally die all at once rather than making you suffer through it. Maybe you got a quality one somehow. See if your plugs are black, that may be a good indicator.

 

(Struggling to find one freaking hour to get under the hood!!)

Finally got to do some work today, and found a couple of things. One REALLY corroded plug wire at the distributor cap (no idea why...). Ignition module is the original GM part - 15 years old. The silicone grease had long since worn/cooked away, and I'm SURE this is the major culprit. Got it all off (and it's a bear to get back there with the hood still in place!) and went to clean up the base with a little WD-40 - well, the magnetic pick-up coil plug just plain disintigrated in my hand. This is 6 pm on Sunday evening - I just KNOW I'm not going to find a plug, much less an open parts store. BUT, thank *** for Autozone - they're open till 8 pm!! Not only that, but the parts guy behind the counter goes WAY out of his way to help me look for a new plug. We even broke out the Wells catalog to see if we could find it there. Well, we're finding nothing (surprise) when he gets this one LAST idea - "Hey - let's see if it comes on the magnetic pick-up coil (I cna be SO lame sometimes)!" So we look - looks good in the catalog - and he's actually got one in stock! $8 - I'dve paid that 10 times over just to get this car running again.

Now I'll have to pull the distributor to change the magnetic pick-up coil, but I can do that (got called back to work tonight - couldn't do it tonight - had the wrench in hand, and had to can it. But tomorrow's another day...)

Will post results...

 

good luck man... I hope that fixes it. It should come up as an ignition modual.

 

kuejo, if that turns out to not be the problem you might have a similar problem as me. My car will just cut right off when driving and will usually start up after a minute. Sometimes it keeps doing it though, it will start up and immediately shut off. Anyway, when it does this, if i unplug the mass air flow sensor it will start and run fine. So if it still happens u might want to try that and see if it stops the problem. I have not yet figured out if it is the sensor itself or the relays, but i should find out this week.

tim

 

I hope to find out today. What you're describing sounds VERY similar to mine, however, and I did replace the MAF sensor when I first got the car. You're not getting any computer codes when this happens?

Definitely keep me posted on what happens...

Jonathan

 

kuejo, i have a custom dash in my car so i do not know if it is flashing any codes when iit does this. I have also replaced my MAF sensor that is why I hope it is just the relays. When my car does this, it just cuts right off like the ignition was turned off, it does not bog down. It just cuts off immediately, is that what urs does?

Tim

 

What your discribing id say its 99% MAF sensor related. By unpluging the MAF, the Computer goes into "limp home mode" and goes to a set numers for air flow. Thats why the car ran better. Other then testing your relays, id say it sounds like you have a MAF sensor problem.

 

It's like someone turned the key off. No hesitation, no chugging, no bucking like you're running out of gas - just plain quits running. Under accelration, under deceleration, under coast - it's all the same.

I'm going to be quite bummed if it's the MAF - that's a whole new set of problems.

JK

 

I thought I would give my 2 cents.my 89 tbi car would die while driving down the road and start right backup most of the time.most of the time it was when I was letting of the gas and slowing down tryed everything .then someone told me to check the speed sensor.mine is on the back of dash.I just disconnected it and the car hasnt died on me since and that was 3 months ago.I get an engine light saying the sensor is bad now but i didnt when it was hooked up.going to replace it but they want $75 for it.so im just dealing with poor gas mileage and an engine light right know.hope this helps

 

Had to remove the distributor to replace the magnetic pick-up coil. Why do they have to position that retention bolt in such an awkward way? Finally had to go buy some of those swivelling sockets just to find something short enogh to reach under the shelf with.

Then the joy of driving out the retaining pin in the bottom of the shaft. You'll want to use a punch just a little smaller than the hole. Wasn't so bad after that - everything came apart as it was supposed to. The only problem was, that the retaining ring (cast into the aluminum body of the distributor) that holds the magnetic pick-up coil in place was broken in two places, with about 2/3 of the circumference of the lip missing. I debated trying to put the distrib back together without the retaining ring, but I HATE southern engineering, and figured that was just asking for more trouble. Could've waited for the Pick-a-Part yards, but then you have the hassle of finding one, pulling it, ensuring that it's decent, and you still have no guarantee as to the longevity of the parts (pick-up coil, ignition module, shaft, gear, etc.) So I called Autozone, and found a brand new one for $109 (plus a $40 dollar core, refundable when I take the old one back in). Now I know I could go to SUmmit and get a Mallory or MSD for $60 to $100 more, but that's still more, and I'm not racing this car right now - I just need it to RUN. So what the hell. I'll get a better one in the future if I find that's holding me back. I think the distributor will be the least of my worries as far as bottlenecks are concerned.

Will continue when I get it back in!

Jonathan

BTW - just diod the fuel pump here about 2 weeks ago - I guess I should be grateful. My brother is doing the pump on his girlfriend's 97 Chevy Pickup - $272 from Autozone, over $500 from the Chevy dealership. And that's just a stock pump (what a GOUGE!!!)

 

Got the new distributor, new magnetic pick-up coil, and new ignition module in, and the car retimed. Seems to be running well, now. No trace of that quitting problem, though will have to run it a few days to be sure problem is solved.

The problem definitely appears to have been the ignition module. Hope this saga helps some other poor schmuck some day - maybe it'll save him/her the aggravation of changing a fuel pump first... (Not that I'm really unhappy - now I've got that nice new Wallbro!!)

Jonathan

 

Wow. An exercise in frustration.

Exact same problem, no better with new ignition pieces. Well, I haven't tried the coil yet - guess that's next. Will let you all know...

Jonathan

 

DAM IT!! well... thats what you call narrowing it down eh? I hope thats the end for this runna round.

 

Finally found some SES codes that may give me some help. 42 and 51.

This car has a Hypertech chip - unfortunately I don't know what chip, or for what mods it was replaced - I suppose it's possible that it is simply for better top end performance and has NOTHING to do with any prior mods (the guy that had the car before me beat on it pretty hard, and I haven't found any substantial upgrades in the car with the exception of the Hypertech chip).

But I also have a stock GM chip which I'll go ahead and swap back in - at least that way I'll know that's not an issue.

Code 42 definitely gives me some meat to work with. WIll let you all know after I track down the rest of the problem.

Jonathan

 

Reset the codes (disconnected the battery) and now I'm only getting code 51. That's been an ongoing problem, so will try to swap the chip and see what happens (in the theme of "one fix at a time"!)

Just for the record - I did NOT install the new coil yet - and may not. Removing the codes seems to have been helpful (???).

Just out of curiosity - can someone explain the difference between a "soft" code and a "hard" code? I'm not sure I'm using those terms correctly, but the way I understand it a "soft" code refers to a code that does not trigger the SES light, but does come up if the ALDL is checked.

Also - while I'm at it - how long do you have to leave the battery disconnected to ensure that the codes are reset? 30 secs? A minute? 15 Minutes?

Car seems to be running well overall - no stalls, no codes, no obvious problems, but haven't taken it any distance yet...

Jonathan

 

You hit the nail on the head.

Give it 10 minutes, just to be sure.

 

Didn't swap the coil, but DID swap the computer. Lo and behold, all codes gone, car starts like a champ, and no stalls yet. Will get out tomorrow for some real driving, but after all that I think it will turn out to have been a faulty ECM.

Sigh. Oh well - could've been worse. I could've swapped EVERYTHING and still not found the problem...

 

'Grats

 

Those suckers have a $140 core charge on 'em at Autozone (and I would imagine that's about the same everywhere). At least the 350 one's do - I'll ask about the 305 ones when I take my core back in. That might just make them worth pulling in the Pick-a-Part yards!

The computer itself was only like $75, but the core is killer if you don't have a trade-in (apparently they're hard to find, which is why the core is so high!)

Jonathan

 

There is no 350 or 305 computer, they both use the same one. Its the calpack that denotes weather it is for 350 or 305.

 

That makes logical sense, (but then again, it IS GM we're talking about...)

Interesting that the computers are so hard to come up with - there's a TON of these 3rd gens hitting the wrecking yards in SoCal (have yet to find one in a Pick-a-Part yard with the TPI still in it - I think those get yanked before they ever hit the yard) but to the best I can recall the computers are usually there - maybe minus the calpac, but the box is the part that's so expensive (core-wise). You would think these remanufacturing companies would have some sort of arrangement with these wrecking yards or maybe they do and it's for pennies - so it's to the yards benefit to try and sell these things to guys like us first - the leftovers go to the reman guys.

I know that right before they crush a line they'll go down the line and pull all the left over calipers, rotors, alternators, starters, and that aluminum air conditioning bottle (condenser?) before the car gets crushed.

I'm also equally sure that the best engines get pulled before the car ever hits the yard - the 454's are ALWAYS pulled (they offer those up front for premium prices) and as I mentioned, the 350 TPI's are always gone as well. I'd be willing to bet a lot of that stuff gets sold before the car eer hits the yard. That's not to say some good deals can't be found - I've pulled my share of Pontiac 455's, 4 bolt 350's, and older (stock) performance heads. But the truly spectacular stuff is rarer than hen's teeth...

Jonathan