I have searched old threads for similar issues, with no satisfaction.
1990 camaro rs 305 tbi automatic lo3 heads
scanned with snap on mt2500
advice appreciated I'm stranded without my daily driver

Symptom,
stalls, no start when warm.

Scenario,
This morning I started my car to warm it up as usual, and was stalled when I came back to it. It then drove fine to tire shop for new shoes, and after leaving it drove fine for 3 miles, then stall, volts were strong when running, but sudden stall when idle or moving. Jumping is no help,
has fuel, getting fuel at throttle body.

No codes were set. not overheating
replaced battery and alternator after I got towed home
battery was old and alt was questionable
Fired right up for about 2 minutes then died again.

I have clean oil, and clean coolant
in last 2,000 miles it has had new: fuel pump, distributor cap and rotor and wires, water pump, hoses, t- stat, plugs have about 5,000 miles, i checked the fwd most drivers side plug, it was in good shape and dry

all vacuum lines seem attached, no loose connections i can find, internal voltage regulator.

the main and only catch... there is a small coolant leak coming from the front driver side of engine where intake manifold meets block/head. clean cylinder, clean oil, no smoke to indicate head gasket
could this be the Ignition coil?
fuel pressure regulator?

 

Any one? advice would be great, i dont know what to do besides take it into a shop, which i can no longer afford...

 

if its leaking from the manifold to the head it could be dumping antifreeze into places it shouldnt be also can make a good vaccume leak... i would start by replacing the manifold gasket and go from there. could also have a fuel pump problem... it may be priming the system but not workin after start up... could need a tune up .... these are just a few things it could be. if the manifold gasket leaks then it needs to be replaced anyway so you might as well start with that

 

That makes sense about replacing manifold seal, but it has been with this slow leak for about 1-2 months now, and ran fine with out stalling previously. When I can get it running, it runs strong and smooth at idle, pumping fuel until sudden stall, exactly as if the key were shut off. When it stalls there is still fuel on the throttle plates (butterfly?) from the injectors.
Im sure the bad seal would cause an issue, but would it just suddenly do this, or would it be a gradual build up?
car has not overheated that I can ever remember in 6 years. it gets hot, but I keep close watch on coolant temps, and every thing in coolant system is new except radiator, which does not leak.

Thanks for the response and help aremy10

 

I had issues with my ignition module going out when hot. Before it would stall out it would misfire a little and backfire while on the gas. After cooling off it would start and drive fine till getting hot again. After time the silicone grease under it will dry up and it will oveheat.

 

ya it could be that too.

if its been leeking for a while then its probebly pretty bad.

 

So today I will dis-assemble and rebuild the entire TBI system, and throw more parts at it to see what happens. plans include tbi rebuild kit, pcv valve and pcv filter.
I will update for and when I find the solution

 

Is the ignition module the same as the ignition coil? with 2 connectors and 1 lead for plug wire? In front of the distributor cap..?
Your car is not a coil in cap is it?

changing the pcv and pcv filter had no changing effect, or cleaning K&N air filter. It started, idled strong at 2100rpm for about 1 minute then died out/stalled.

Also, what component or specfic system is responsible for the fast idle at warm up(initial start up)?
What makes the idle decrease as engine heats up?

I got it running, shifted into drive and it stayed on @ around 800rpm in drive, lasted 5 min. Shifted into park, lasted only 1 more minute.
it seems like once the engine get warm a little, it stalls
tps, iac, map v, map kva, all with in normal operating range as per mt2500
suggestions?

 

No it is under the distributor cap on the back side. Held in place with 2 screws and there are 2 connectors (1 on each side with 2 wires each)

 

maybe the choke is stuck shut watch it to see if it opens when it warms up if not then disconnect it till you get if fixed

thats right throttle body oops

forget that last suggestion forgot you had throttle body. any way throttle position sensor? bad gasket under carb? maybe idle air control valve is bad....or pressure regulater or an injector

 

although no start when warm to me kind of indicates the ignition module is junk. i ve had the same things happen and thats what it ended up being

 

I replaced the IAC, and the tps reads with in limits on my mt2500 scanner as do all sensors with in range...
I found a few clear-ish yellow boogers in the pcv vent to filter/air cleaner tube. looked in valve covers, none there. or the oil breather on other valve cover drained all the oil, it was clean, no coolant or water what so ever in there.
when it was running I sprayed all around it with carb cleaner and wd 40, this had no effect on idle.
I will check out ignition module tomorrow, and post update.

BTW, 268,132miles on this gem.

 

I just pulled the #7 plug and discovered MASSIVE ASH DEPOSITS on the electrode! I am a faithful user of marvel mystery oil with every fill up.
As per Haynes manual photos (looks exactly the same) oil and fuel additives can cause this, or leaky valve stem, would marvel cause this too? on my way to get plugs. will update later
EDIT.replaced plugs and ignition module(greased too), no difference, still stalls as it reaches operating temperature
does any one know exactly where the fuel pump relay is? there are 2 relays behind/ next to the brake booster
this is a 1990 rs camaro TBI 305ci

ANY input on the clearish yellow boogers in pcv tube? ANYONE?

 

Problem solved...
Stalling issue is apparently gone, the biggest difference was cleaning out the Air Management Valve breather vent(clogged with carbon; located near passenger side valve cover) in conjunction with starter fluid on cranking.(perhaps throttle was sticking under its own power?)

To reiterate, in the third phase of work I pulled the ignition module(grease was white and dry, flaky) I put in another ig mod, well greased, from a 70s full size pick up, replaced all plugs (#7,8 were covered with massive ash deposits).

Before this,the following parts replacements had no effect on my problem: IAC and gasket, alternator, battery, ignition module, oil and filter change, cleaning of K&N air filter.
THANK YOU EVERYONE, for input and advice, it has been greatly appreciated.

The only issue now is intermittent engine vibration after slowing down and stopping, not every time. (It sounds like bass/bumping stereo system from engine) this goes up and down

 

LET ME START BY SAYING
So I bought throttle body cleaner, removed IAC, cleaned iac port, throttle valves, springs on sides of TBI unit, removed and blasted out all vacuum ports and pvc(chunks in bottom of pvc port) and generally sprayed all pertinent points repeatedly,
High/ climbing idle is GONE!!!!!!
Thanks to all who replied for you support, assistance and advice.

 

been running rough last 2 weeks, It happened again! stalled several times, once at light, twice under heavy acceleration, and again under normal acceleration. Wondering if it was used ignition control module failure... Currently on side of road broke down. planning on replacing with new ign cont mod, and new ignition coil...
any other ideas?

what would cause deposits in the air management valve breather? the basket thing at the end of the down tube, bolted in around the air pump tube...

 

When it wont start, check spark. Bet it wont have any. When you replace the ign mod with a new one from GM, test the pick up coil. Its just above the mod in the dist. Green wire and white wire. It should test at 500 to 1500 ohms. It may only fail when hot. Try tapping the dist with a soft mallet while watching ohmmeter. If you see any change replace coil. Fact is, I replace this coil any time I replace ign. mod. Too many comebacks.

 

are you talking about a coil in cap dist.? i dont have coil in cap, its next to it, as a seperate unit. what is best grease for the ig cont module?

 

.die electric grease. I spelled that wrong didnt I?

 

The proper grease for the ignition module is di-electric grease. Make sure there is plenty of this slathered on the underside of the module or it will burn up. Use nothing but this type of grease on it. You mentioned that it stalls when hot, maybe a vapor lock problem? Does this occur more frequently on hot humid days or is it when the engine is hot in general? Now the no start. Is it that the engine will crank but not fire or that it will not crank at all?

 

It turns out it was the ig module, or the grease, the new mod came with WHITE SILICONE GREASE. the spark plug clear grease is not the right thing to use, it what i used before, it gets hot and melts away.
thanks folks!

 

nobody said sparkplug goop..... I use the di-electric grease on spark plug boots tooo..... does not melt....welll for a long long time..

 

nobody said sparkplug goop..... I use the di-electric grease on spark plug boots tooo..... does not melt....welll for a long long time..[/quote]

I posted last month how i used the plug grease on the module, earlier in this thread, but this was only a temporary fix, and it melted off after about 40 days or so.
Amazing difference with new module and proper grease

 

I know that your small body hei is external coil. You need to look more closely under the dist cap. The pick up coil is above the ignition module. It is a small circular coil wrapped in what looks like masking tape. It connects to the module via a two wire connector (green wire and white wire). This coil produces the primary ignition pulse which the ecm uses for injector control and which the ign mod uses to control ignition events. It is a common failure item and I replace it anytime I replace the module.

 

I know this thread is closed but I wish to clear up any confusion I might have caused for anyone reading it. The pick up coil, in most cases, is in a metal housing above the ign module. Some early units were encased in a fiber wrap which looks somewhat like masking tape. Two wires, one green, one white come from the bottom of the coil and connect to the back of the ign module. Replacement of this coil requires removal of the distributor shaft.

 

ive got a 1989 firebird with a 3.1 out of a camaro, the car stalls sometimes in park and also in drive i was wondering if it had something to do with the distributor or?
also sometimes when i turn on the brights the car stalls, would that have something to do with distributor, alt ? service engine light comes on after about 10-15 mins of driveing, any help would be apreciated

 

Stalling when turning on the brights is usually an indication of battery cable deterioration. Assuming alternator is working properly. This is just a general statement .