Stalling at stop

[Belsy]

My 90 recently started to stall at slow down to idle(as approaching stop) yet restarts and runs fine with no codes!! Seems to be worse with A/C on. Only recent change was 3" exhaust eliminating much back pressure, other items are Haibeck chip and open air box which seemed fine till recently. 30,000 mile car w/ new plugs and wires at 28,000 miles. Open for suggestions!
Any thoughts???
Gene in Fl.

[jonszr1]

ck your iac, could be dirty or bad. also ck tps to see if it is .54. 3rd ck to see if map sensor hose has come off.

[Belsy]

ck your iac, could be dirty or bad. also ck tps to see if it is .54. 3rd ck to see if map sensor hose has come off.
Stupid question, when you say iac do you mean air filter?

[Belsy]

Stupid question, when you say iac do you mean air filter?
Sorry, senior moment, iac may be the problem as I read the service manual and my idle fluctuates up & down. So is the iac driver they refer to a special tool and if so where can I get one ?
Thanks,
Gene :-({|=

[jonszr1]

Gene , no problem we all gotta learn , iremember all my ?s at first. but the guys were nice and still helped . the Iac is on the passenger side of the throttle body . there is a water tight connector on it . it has 2 small torx bolts that hold it in. there is also a o ring that dreates a seal . you could take it off and spray carb cleaner on it . just be carefull dot wipe it just spray.. a couple of thoughts . have you cked the pvc val;ves or the rubber hose where the pvc valves located for a leak these have a tendancy to go bad. DO YOU HAVE A HELMS MANUAL. if not get one they really help alot .just take your time looks scaryer that it really is. or see if there is another zr1 er in your area that might help ya out .

[Belsy]

Gene , no problem we all gotta learn , iremember all my ?s at first. but the guys were nice and still helped . the Iac is on the passenger side of the throttle body . there is a water tight connector on it . it has 2 small torx bolts that hold it in. there is also a o ring that dreates a seal . you could take it off and spray carb cleaner on it . just be carefull dot wipe it just spray.. a couple of thoughts . have you cked the pvc val;ves or the rubber hose where the pvc valves located for a leak these have a tendancy to go bad. DO YOU HAVE A HELMS MANUAL. if not get one they really help alot .just take your time looks scaryer that it really is. or see if there is another zr1 er in your area that might help ya out .
Thanks, I have done this on L98s so should be OK, are these a ZR-1 only part or can I find new one easy? I have factory ser. manuals and a Haynes which seems easier to muddle thru.
Gene

[jonszr1]

you got the big fat red manual with the electric and engine suplement.they can really bug ya on the order of things in the book. but once you learn that system its way more detailed than the other. ck the map sensor vac line .it at the back of the motor up against the wall

[UKZR1]

My Z has started doing the same thing. I've alreday checked the MAP sensor hose. I will try cleaning the IAC next

thanks

[jonszr1]

the best piece of equipment i got is the scann tool .i keep it hooked up even while driving . it really lets you know how your caris doing. help diagnostics too. jmho

[bobbyhi]

the best piece of equipment i got is the scann tool .i keep it hooked up even while driving . it really lets you know how your caris doing. help diagnostics too. jmho

What scan tool do you use? I don't have one yet and was thinking about looking for one. Any recommendations??

[Belsy]

Cleaning IAC worked for me , I use starting eyther to clean parts like this drys fast , sprays hard and won't destroy stuff!! Take toothbrush or
Q-tip to clean cavity on throttle body, mine was caked with goo.

Gene in Fl.

[jonszr1]

I have an auto xray 4000 . just make sure you dont a reader it wont give you real time readouts of the sensors

[QB93Z]

I have an auto xray 4000 . just make sure you dont a reader it wont give you real time readouts of the sensors

The AutoXray 4000 info says it works on OBD II. Will it work on a 1993 ZR-1?

Thanks, Jim

[jonszr1]

opps very sorry mine is a 3000. old guy with CRS:mrgreen:

[TommyL]

I had this exact problem with my 90, turned out to be the speed sensor on the drivers side of the trans. I'm not saying this is your issue but it was for me...worth a look.