LqMth

I know everyones gonna jump all over the opti right away but I dont want to go broke trying to diagnose this. Yes I did extensivly search the subject. Anyway here goes. It started out as a slight stumble once in awhile almost like it was running out of gas. The problem got worse over the timeframe of a week or two. I did the simple things like fuel filter, plugs, wires. It had no effect. Then last thursday I was sitting in traffic in town and it just died. It would crank until I have it full throttle then it would fire-up. It ran long enough to get to the side of the road. Had it towed...thought it was the fuel pump. Put a new one in saturday. Went for a ride and everything seemed fine. As soon as the car warmed all the way up it started stumbling like it was out of gas again and finally died while I was just driving along. I hit neutral and it fired back up. Ran until I got to my friends were I let it cool a little. Started up and SES lite came on. It ran horrible for awhile and then the light went off and it seemed better. I babied it home with-out much trouble and its been sitting since. It seems to only do it when fully warm although I dont think it has anything to do with closed loop. I also notice when it wants to die it seems to stay running longer if I give it more gas. I have no idea anymore. I can only think ICM, coil, or opti . Sorry its so long but I wanted all the details. Any help would be appreciated.

Nathan

slopokrodrigez

If you suspect that heat is the cause then use a blow dryer to determine the defective component. Be sure the engine is bone cold and heat one device at a time then try to start it. Don't run it long enough to warm anything up. Then warm the next thing up and try again. Be sure to try it a couple of times before you go replacing anything.

LqMth

Thanks for the info I'll try that. Just ordered an ICM today. I know the coil was just replaced about a year ago...doesnt rule that out but I'll start with older components. I just hope its not the opti because I'm already sick of cruisin the bronco and its been less than a week.

1993BlackZ28

how warm does it get ? like up to the red almost? or just half way?

if you dont already i would suggest running w/ your defrost on but dont turn the blower on. it turns the fan on and keeps my car cool. just turn the right **** all the way to the right and see if it keeps it cool.

LqMth

Sorry for the confusion.....it doesnt overheat. The temp is normal.... goes no higher than halfway ever. The car only acts up when it begins warming up. It gradually stumbles more as the temp gets closer to normal. When it does the car begins to die. I am going to scan the car today to see if it stored a code when the SES light went on. Last time I cleared the codes was when it began acting up. There was a code of Coolant temp ckt to high or open. The car never overheated though so maybe it has something to do with the sensor? Anyone know anything about this? THanks

Nathan

spiritguitar

Nathan...if you find out what it is please post it. My '97 does the same thing - runs great when cold, but as soon as it gets to normal temp it acts like it's getting no fuel and will barely crawl to the side of the road. Once it cools off, it's back to normal.

I tried to scan it using a friend's scanner but the computer would not make contact with my engine, although it made contact with his Boxster. The scanner is listed as compatible with GM vehicles. I'm about to surrender and give it to the local Chevy dealer. If I get an answer first, I'll post it and let you know.

Good luck...RD

LqMth

*Update* Installed my ICM today. Still have the same problem except now the check engine light was on as soon as I started it up. It ran like it was running out of fuel while it was cold...didnt wait until it heated up this time. I threw the scanner on it and got the coolant temp code again. This time I also got a MAF code so I unplugged it. Still didnt help. Car bucks and stumbles all through the rpm range. Will do further expermintation later but I have to go to my graduation tonite . It was close but I pulled it off. Spiritguitar---thats how mine was originally...hope we can figure this out. Since now I dont think its heat related anymore it opens up a broader list of possible culprits. Maybe it will help with your ideas?? Thanks for reading. Nathan

Camaro97USAF

My car does the exact same thing, throwing a code p0125, for coolant not heating up sufficiently to go into closed loop. I might try changing the sensor in the water pump again. Other than that I'm stumped.

Lt1t56

Having same problem here, runs great until it reaches operating temp 200 degrees. Took ICM to 2 different O'reilleys stores for testing, both said it was bad, so purchased one also bought coil since only $25.00, installed new ICM and coil and used washers between head and coil bracket to help keep it cool, still dyes, tryed PCM out of my other LT1 car, still dies. Doing OPTI now.

Robert_K

My car has almost the same problem. It runns fine when cold but when it gets warmed up it sounds and feels like the engine is misfiring or sputtering, kinda like its fanning the throttle. I am also have trouble starting the car, it seems like it cranks forever when the car is warm. If the car is in the shade and has not been touched for the last 8 housrs or so, it starts up great with no problems. Will changingthe coil help? I heard one of the reasons for my starting problem is the coil not producing enough voltage. Can this be true? I also changed my IAC valve and noticed the when the car started it didnt bog at a log RPM anymore, or even die like it sometimes did.

roadtrip120

A friend of mine had his opti go out. It just back fired a couple of times and then it was out. We tested the injectors and sure enough it was gone. So we went the cheap route and put an old opti back in, the new/old opti had 120XXX mile on it. The previous owner said that he thought it was going out. After the hour install it fired right up but it seamed not to have the power that a cammed car should have, or at least it didn't feel like it old self. It had a weard stumble and seamed liked it messed threwout the power band. So my friend forked out the 200 some odd cash for a new one threw Jason Cromer. After another hours work the halled, like a raped ape agian. I'm not sure if this is any of your problems but consider the mileage of your car. I pulled mine apart at 125,000 and the opti showed major signs of age and wear. But no money , no new opti. So still runin strong.

Hope this helps

Robert_K

My car stubles and shakes off idle and practically runns like crap. Do you suggest I buy a new opti? My car has 132,000 miles on it and I dont think the previos owner changed it. What can be the symptoms of hard starting (the engine cranks fast, it just takes forever).

greatwhitez

I had the same problem. The car would stumble and die out when hot, and it was very intermitent. I traced it back to the coil and icm on the cylinder head. What i did was cut a piece of square plastic out of a big oil drum i had laying around my work and use is as a barrier to go between the head and the coil/icm bracket. This fixed my problem, so maybe i'd give it a shot.

LqMth

Thanks for all of your replies. I think i'm going to invest in an opti as soon as monday rolls around. I guess I'm not to disappointed since the car got 130k out of the original one. At least I got all of those new parts trying to figure out the problem. I'll keep you updated. Nathan

Camaro97USAF

please do, I'm dying to get rid of this crap