Wish it was a TII

Recently I've been having a problem with my 1988 non-turbo where after it has been warmed up, when the clutch pedal is pressed (as when stopping at a traffic light), the RPMs drop below normal idle, the engine struggles a bit, and sometimes stalls. If it doesn't stall, the idle almost immediately returns to a normal 750rpm.

The car starts up fine after it stalls, and aside from the intermittent stalling itself, there are no problems. I checked/adjusted the TPS yesterday in an attempt to correct the problem (it wasn't far from where it was supposed to be), and it stalled when I took the car out for a ride this morning. Keep in mind I stopped about 5 times at stop signs during the trip, and only once did the RPMs drop low enough to stall it.

Any ideas? Thanks in advance.

jetfire76

replace/upgrade the ECU ground. firewall(right next to the windshield wiper motor) to bellhousing.

edit: forgot to ask...when you slow to a stop w/ the clutch depressed, do all the idiot lights come on and then it just dies? if so, do the above.

-jet-

Wish it was a TII

Anyone else agree with that assessment? I will look into that ECU ground. Just curious though... would a bad ground there cause the problem I'm having, and no other problems whatsoever?

From searching the forum, I was getting concerned it was the BAC valve. I haven't tested it yet, though.

Anything else that could be causing it? I'm certain it isn't low compression, as I checked that recently with a tester, and the car runs strong aside from the occaisional stalling.

Wish it was a TII

Sorry, I didn't see the last part of your post... yes, when the car does stall, all the idiot lights come on. A few times, when it came very close to stalling but didn't, I saw the idiot lights flash briefly then go off as the idle returned to normal.

Edit: It should be noted that more often than not, when the engine struggles when coming to a stop, the idiot lights DO NOT come on. They only come on when the car stalls, and rarely when it comes close to stalling but doesn't.

SureShot

Also test & clean the BAC.
Then go through the idle speed set procedure.

Wish it was a TII

By the "idle speed set procedure", you mean hooking up a tachometer and adjusting the air adjust screw on top of the motor? If the car usually idles solid at 750rpm as mine does, would that really need to be adjusted?

Sorry for the dumb questions, I only have a basic knowledge of how everything works on the car.

Also, how does one go about cleaning the BAC? I'll do a search for it, but if someone could provide a link I'd appreciate it.

SureShot

The short version--

BAC cleaning: Take it off, spray with carb cleaner, blow it out, test if 12v on the pins pulls the plunger.

Idle set: Engine running, no extra loads, ground the initial set connector, adjust RPM with bleed screw.

The FSM (fuel & emissions section) has more details. There is a link in my sig.

jetfire76

quite a few peeps here have had your problem(do a search on "clutch stall"). most cases it was solved by replacing that simple ground. sounds kinda strange i know but it worked. but try the other stuff Sureshot suggested as well. it wont hurt.

Wish it was a TII

Thanks guys! I will try those things until the problem goes away!

Wish it was a TII

Oops, one last thing... Jet, that ground you are talking about... looking into the engine bay from the front of the car... is it a spade connector located just to the right of the windshield wiper motor? I see a black wire there. Is that what should be replaced?

jetfire76

yup, that's it. it just sorta clips on. follow it and it will lead right one of the bolts on the bellhousing.

Wish it was a TII

Okay, update... I reinforced the "ECU ground", the car still stalled on occaision. I adjusted the idle speed to where it is supposed to be (it was very close before), and it still stalls. Set the TPS... same.

I am now at the BAC valve stage. Ran the car at idle, unplugged the BAC valve... no change in the idle whatsoever. Did a resistance check on the two terminals on the BAC valve, and it was 13.8 ohms. Is this acceptable?

I am about to embark on the next stage, which is applying ground to one terminal, and 12 volts to the other terminal, and listening for a click. I'll have to do that tomorrow. Anyone think I'll hear one? Any comments at this point?

Thanks!

Ambrose Winslow

I have exactly the same problem on my '87 non-turbo, so I'm paying close attention to this thread. THe problem started to develop about six months ago when the dealer installed a new throttle position sensor. Its gotten worse since then. My dealer adjusted the idle multiple times but now says that the problem is low compression. I don't agree because the car runs fine otherwise.
I have two questions. What's the BAC valve and where do I find it (I have a shop manual)? Also, why would a ground wire cause the car to stall only at certain times?

Thanks for all your help.

jetfire76

so did you fix the problem?

OtakuRX

iTrader: (1)

My GTUs does the same only when the A/C is on though.

hugues

If the BAC is working, make sure your idle is set correctly. Make sure you have no vacuum leaks (otherwise the idle can not be set correctly) and make sure the charging system is up to snuff (otherwise you are putting too much strain on the engine at idle)

http://www.geocities.com/huguesdc1/idlecontrol.html

http://www.geocities.com/huguesdc1/faqidle.html

hugues -