kfrank

I have a 94 LT1 out of a Buick Roadmaster in my Jeep. Been running this setup since 1999 and have never had any problems. Water pump has been leaking for about a year (small Leak) with no problems. About 3 months ago, I fired the Jeep up, backed it out of the garage and after about 5 minutes it died. Tried starting it a few times but nothing just the smell of gas. About an hour later it fired right back up but with a check engine light. The code was for the VSS. Anyway, I obviously havent driven it since just start it every few days. Everytime I start the jeep , it runs like a scalded as ape, however, once it gets warm (2 or 3 miles) it dies as soon as you give it any gas. Yesterday and today i changed water pump and optispark wires etc. Fired her right up and the same ole thing is still happening.

Basically, when cold runs great, when it warms up idles weird and when throttle applied it chokes down and dies.

Anyone experienced or know of this problem? Any input would be very much appreciated.

The only DTC i have is 97, which is the Vehicle Speed Sensor.

kfrank

When I start it cold, it starts with a check engine light on. Once it gets warm, runs like **** the check engine light turns off. Seems backasswards to me.

kfrank

Anyone had this problem or have any advice?

GRIDERMAN87

get it scanned, see what the codes tell you

kfrank

The only code it has is 97. Vehicle Speed Sensor

RamAir95TA

Sounds like ICM heatsoak failure or coil failure. An electronic components worst enemy is heat, and prolonged exposure to heat can weaken electronic parts and ultimately cause them to freak out once they heat up. I would try replacing the ICM and see if that helps.

kfrank

I replaced the coil last night and it still runs the same. I am going to replace the ICM this evening. Hopefully this will help narrow it down further.

kfrank

Again, when cold it runs great. Once it warms up and goes into closed loop it spits and sputters and once you give it a little throttle it dies and wont start again for an hour or two.

I have changed the water pump optispark, rotor, coil, ICM and EGR valve. Nothing has changed at all other than it running better when cold from the new optispark. I am puzzled... Still no progress.

Any help would be appreciated.