94adam89

I bought a 95 and have started driving it recently. Sometimes while im driving the motor will start to cut out. It feels like someone keeps turning the key on and off while im driving. A few. Times even cometely shutting off. When i try to restart it wont even try. But if i wait maybe 30 seconds and try while holding the throttle wide open it fires again . Bad opti or fuel pump?


Doing what I like and not what I should!

shoebox

Need more details. Does it crank and not start or what? If it cranks, have you checked for lack of spark or fuel pressure when it won't start?

94adam89

Yes it does crank. Checked fuel pressure today and it 40 psi key on. And 36 psi while running under load. As of right now im sitting on the side of the road.


Doing what I like and not what I should!

shoebox

Still good fuel pressure when it won't run? Then check for spark.

94adam89

Its got spark too. Im going to get a coil and try it. And a fuel filter too. It will start if i hold the throttle wide open but shut off almost immediately. How do i check my regulator. Seems as tho i have plenty of fuel pressure, because it smokes black when it does finally start


Doing what I like and not what I should!

Injuneer

Pull the vacuum compensation line off the fuel pressure regulator, and look for wet fuel in the line. Put a fuel pressure gauge on the Schrader valve and check for incorrect fuel pressure.

94adam89

Ok so... I put a new coil on tonight. The car started but still has a bad dead misfire in all cylinders at random times while driving.

Checking fuel pressure again. I have 35-36 at idle and about 40 wide open throttle. When unhooking vacuum to the regulator i get a steady 40 psi idling and wot.

What is the electronic piece that is bolted together with coil? I suppose it is some ignition component? Can it fail?


Doing what I like and not what I should!

Injuneer

You really need to familiarize yourself with Shoebox's website - it is the best source on the Internet for LT1 information.

http://shbox.com/1/4th_gen_tech1.html



The coil is attached to the ignition control module. The ICM is bolted to the driver's side head. It has a tendency to heat soak, and can cause misfire problems. Rob/Shoebox has a suggestion on spacing the ICM away from the head to mimimize the heat soak.

94adam89

Well i replaced the ICM tonight and it seems to have cured what ails it. I sure hop this is a permanent fix!


Doing what I like and not what I should!