85 vette get hot and dies

[Dave Orr]

i have a 85 vette and the last 3 times i drove it i got towed home it runs and idles fine but when you drive it for about 20 min it starts running rich and then dies and will not start up till it cools off.any body got any ideas help!!!!!!

 

[c4c5specialist]

HI there,
Check your fuel injector resistance when this happens.
You probably have 1 or 2 that are shorting out.
16.5 ohms is your specification.
Allthebest, c4c5

 

[CAJUN C4]

Sounds like the Coil.

 

[onedef92]

Sounds like your ignition control module (ICM) to me. Mine died suddenly and took my coil out with it, resulting in an immediate crank, no-start condition.

You can have your ICM tested at NAPA, Auto Zone and other auto parts stores.

 

[bradfordsvettes]

all three items deserve a look at, all will give a similar senerio only problem is the tests will probably need to be done when it dies Steve

 

[flightdeck2]

I just had a simular problem with my 85 and turned out to be the fuel pump.Low pressure creates a lean condition and will overheat,The low pressue will create a vapor lock.Put a gauge on the fuel rail.Should be around 40 PSI and hold.

 

[tonylong]

Sounds like your ignition control module (ICM) to me. Mine died suddenly and took my coil out with it, resulting in an immediate crank, no-start condition.

You can have your ICM tested at NAPA, Auto Zone and other auto parts stores.

I've seen this issue reported before. I can't find an ICM on my 89. Is it just the circuit board in the harness connected to the dist cap?? MAD sells such part for $80.

 

[onedef92]

I've seen this issue reported before. I can't find an ICM on my 89. Is it just the circuit board in the harness connected to the dist cap?? MAD sells such part for $80.

I don't know the location on an L-98, but on an LT1, it's located near the coil. Check your FSM.

 

[tonylong]

re ICM My FSM only shows a "Distributor Module". It's found under the Cap, a small 5/8" x 1" held by two screws, all wiring seems to be beneath the module. Is this the ICM?

 

[c4c5specialist]

HI there,
L98 has an IGNITION MODULE, located beneath the distributor cap.
It fires the coil AND ALSO, sends the signal to the PCM to fire the injectors.
Allthebest, c4c5

 

[tonylong]

HI there,
L98 has an IGNITION MODULE, located beneath the distributor cap.
It fires the coil AND ALSO, sends the signal to the PCM to fire the injectors.
Allthebest, c4c5

Ahh yess that seems like the critter. I'm gonna try replacing that. It fits my symptoms of starting up OK then craps out after warmup.

 

[onedef92]

Ahh yess that seems like the critter. I'm gonna try replacing that. It fits my symptoms of starting up OK then craps out after warmup.

Don't forget to apply the small packet of thermal transfer grease that should come with the new module. If you don't, your new unit will stir-fry itself to death in short order! hnoes

Remember, you can remove your ICM first, then have it tested. No sense in throwing money at parts!