Most puzzling (and wastefully expensive) car problem ever.

[Haunz 10+ year member]

It's probably a bad spliff-coupler....

 

[thevic24 5,000+ posts]

Now that you mention it, that could be a good place to look for the stalling problem at idle, but I don't necessarily see it causing the acceleration problems. I think though that it may be a compounding issue. Can I check the IAC by unplugging it?

Not really.

IIRC, take the IAC out and measure the distance from the mounting flange to the tip of the pintle.

should be aroudn 1"

Let me ask, have you disconnected the battery recently?? If so, sometimes the ecu needs to relearn the idle.

The iac can be the problem tho.

Dam obd1 cars, they are a pain to diag.

Keep in mind that at any point, you can use a paper clip to jump a and b terminals on the data link connector to get your codes.

the check engine lt will flash them out to you.

the very first should be 12- one blink followed by 2 blinks, pause and it will repeat. just count the pairs of "blinks"

code 12 means that the ecu is communicating correctly.

 

[Big GeRm 10+ year member]

I forgot how...but google how to clean an IAC...and see if it helps any.

 

[cotjones 10+ year member]

Not really.IIRC, take the IAC out and measure the distance from the mounting flange to the tip of the pintle.

should be aroudn 1"

Let me ask, have you disconnected the battery recently?? If so, sometimes the ecu needs to relearn the idle.

The iac can be the problem tho.

Dam obd1 cars, they are a pain to diag.

Keep in mind that at any point, you can use a paper clip to jump a and b terminals on the data link connector to get your codes.

the check engine lt will flash them out to you.

the very first should be 12- one blink followed by 2 blinks, pause and it will repeat. just count the pairs of "blinks"

code 12 means that the ecu is communicating correctly.

Yea I actually have a little keyring tool made to retrieve the codes, works for break systems too.

pulled codes are

33/34: Map sensor vacuum supply high/low

and 44/45: Exhaust rich/lean.

 

[cotjones 10+ year member]

The idle issue is interesting. Say for example when i come to a stoplight, It will idle somewhat normally for about 10-20 seconds, then randomly rev up slightly, and then back down and stall. It's a pain having to restart the **** thing every time i have to come to a stop in wilmington "1000000000 stoplight and you hit them all" traffic.

 

[bhsdriller 10+ year member]

get an italian chip in it asap

 

[Imtjnotu 5,000+ posts]

get an italian chip in it asap

 

[cotjones 10+ year member]

HOLY SHIX i've never been defended on this site before. LOL thx, this must mean the world really is gunna end soon.

 

[Imtjnotu 5,000+ posts]

HOLY SHIX i've never been defended on this site before. LOL thx, this must mean the world really is gunna end soon.

haha i remember all the times people gave u **** and maybe i use to but ive grown the fuckk up since....plus his trolling attempt was terrible...and because im somewhat a gear head...but check into leaks and the fpr and report back

 

[cotjones 10+ year member]

haha i remember all the times people gave u **** and maybe i use to but ive grown the fuckk up since....plus his trolling attempt was terrible...and because im somewhat a gear head...but check into leaks and the fpr and report back

will do

 

[#45 10+ year member]

Catalytic converter? i've seen em go bad in trucks causing a couple of the symptoms mentioned. is there a way to check it just to rule it out?

 

[tommyk90 5,000+ posts]

I've been fighting similar issues with my 1990 s-10 4.3.

Gone through the replacement parts roulette game you are doing now with no changes. o2, IAC, MAP, TPS, I went through them all without changing anything.

I got an electrical issue somewhere. My alt does some crazy things so I'm going to switch that out and go from there.

I also have that same exhaust leak you are talking about. Mine has been there forever as well so I doubt it's the culprit on my truck either.

I've all but given up on trying to figure it out. It all started in feb. 2009 when I first started getting check engine lights and seems to have progressively gotten worse.

If you find anything out on yours I'd be interested to know.

 

[thevic24 5,000+ posts]

This may be a long shot but I had a 92 Lummina Z34 that after a while started to do the same things.

It was opd1 as well. Kept giving me the same codes over and over even after I had replaced the "bad" parts.

In the end, it was the actual ecu that was at fault. It was the actual ecu box, not the chip.

The only problem with that is once you buy an ecu and install it, its yours. So if it dose not fix the problem, you

are stuck with an extra ecu.

What happened with that was the circuit board in the ecu had some corrosion on some solder traces. I replaced just the ecu and re used the

original chip(just snaps in) and it cured everything.

 

[tommyk90 5,000+ posts]

This may be a long shot but I had a 92 Lummina Z34 that after a while started to do the same things.It was opd1 as well. Kept giving me the same codes over and over even after I had replaced the "bad" parts.

In the end, it was the actual ecu that was at fault. It was the actual ecu box, not the chip.

The only problem with that is once you buy an ecu and install it, its yours. So if it dose not fix the problem, you

are stuck with an extra ecu.

What happened with that was the circuit board in the ecu had some corrosion on some solder traces. I replaced just the ecu and re used the

original chip(just snaps in) and it cured everything.

Sadly enough, I have already tried that as well. I had the original ECU from my truck before I put the wiring/dash/etc. in from a wrecked blazer we bought for parts. Swapping that out didn't change anything.

I guess I'll have to go over all my connections again to make sure something isn't simply corroded or broken.

 

[audioatg 10+ year member]

Didnt read the whole thread. But have you checked for vacuum leaks. Betting its a simple vacuum leak. At the throttle body area. Gasket maybe.