I have a 93 LT1, 6 sp. 100K miles. A couple of nights ago I drove the car to visit my wife is in the hospital (she is OK and back at home). About 1/2 mile from the hospital, the LT1 start to idle very badly in heavy traffic. Then it dies a couple of times but I manage to restart and keep the revs high. I just made it in the hospital parking structure and found a spot. By this time it was dying even if the revs were high. Parked it in the structure and left it for 2 days. After I got my wife home, I went back the next day to put the vette on a trailer. At this point it turns over but will not start. Oddly when I tried to start it in the parking structure it would kind of backfire after the cranking stopped. Got it back home, no chance to pull codes yet. Any thoughts, the Opti is suspect. I have no history on the car before
90K miles. No leakage on the Opti. Any thoughts???? Thanks.


UPDATE: No codes, getting fuel but pressure not yet tested. SparK appears to be weak (yellowish) and intermitant when cranked. Any thoughts. Coil/module, OPTI, ECM, are the top choices.

Update 2: It was the coil and or the ignition control module (ICM). About $110 for both at AutoZone. It runs like new again. Thanks for all the opinions, that does help.

 

It is extremely rare for an opti to just stop working without any prior symptoms.

The backfiring suggests you have fuel but not spark.

No SES light?

 

No SES light.

 

Also no prior symptoms, I had just commented to my wife how good it had been running.

 

Given: no prior symptoms, no codes, no exploded rotor (because it ran again after the initial problem) I think it isn't the opti.

Beyond that, I'm thinking maybe ICM or coil.

If I've got the right Oak Hills - near Victorville - then that also suggests ICM - they go bad from heat even in cool climates.

My suggestion is to head over to the LTx forum at camaroz28.com - some of the best minds in LTx diagnosis hang out over there.

 

About a month ago I had a similar problem, doing some running around my car died on me, got it restarted, went about a mile and it died again, after the 3rd time I parked it and got my trailer. Got home and no codes replaced both the ICM and coil and it started right up and has ran fine since.

 

My first guess would be the coil, check for spark and good luck. Glad your wife is o.k. John

 

Thanks for all the responses. Will check it out this week.

 

UPDATE: No codes, getting fuel but pressure not yet tested. SparK appears to be weak (yellowish) and intermitant when cranked. Any thoughts. Coil/module, OPTI, ECM, are the top choices.

 

If it was an old car, I'd say timing chain jumping gear teeth - dead ringer.

But it ain't, so... ?

Codes is all ya' got to go by. ???

Backfire AFTER you let go of the trigger?

 

I just went thru the exact same problem 95LT1. It was the opti cap, 2 circuits burned out. I replaced cap and rotor and it runs perfect. I did also test coil and ICM in the process and they were OK.
Bob

 

Thanks Bob. My suspicion is the opti. Have some spark but it seem untimed or random. Will check the coil and ICM then go after the Opti. I am not getting any error codes but but I do get the "12" delimiter which, in my mind at least, indicates that the ECM is OK. We will see. Thanks again to all for your input.

 

Update 2: It was the coil or the Ignition control module (ICM). I replaced both and off it went. Because it went out in heavy traffic on a hot SoCal day. I kinda ruled out the Opti in my mind and I was correct. Again no codes.