ok so im new to this forum and im desperately seeking help. I have a 95 z28 and its a beautiful car and i love it to death but lately its been nothing but a nightmare and headache. At random times the engine will stall and die on me. i have gone thru the ringer on this thing, generally it happens after the engine has heated up. but its happend a few time just after a few minutes of running. Ive also notice that if i push it to WOT ill get a what feels like a slight missfire at high rpms. (5500-6000 range). also it has a very rough idle immediately after i start it. however after driving and going into park, it will idle at around 1100 rpms and slowly climb. along with all this it has been getting horrible gas mileage.

since this problem has occured i have replaced the opti, tps, O2 sensors, pcm, plugs and wires, and i have cleaned the IAC, and MAF. non of this has resolved the issue. im wondering could the knock sensor be causing this? any help or suggestions as to what is going on with my big red money pit would be greatly appreciated.

also there are no codes being thrown

 

Check your ignition control module:

What's a bad ICM and/or coil feel like? - LS1TECH

That could be the problem.

Test it then let us know what's up. I'm sure other forum members will chime in as well.

Good luck and kill Rustanks!!!


x01660

 

Have you checked the Ignition Control Module and the ignition coil? These should be checked out before thinking about replacing the opti (much easier and cheaper). Make sure the fuel filter and air filter are clean. Also check fuel pressure with engine under full load to see if the fuel pump and regulator are up to the task. A weak pump may be able to check out good with no load, but fail to move enough fuel to maintain pressure at full load.

 

icm and ignition coil tested out fine, ive already gone through and cleaned the air filter and replaced the fuel filter. im going to test the fuel pressure when i get my next available chance and post what i come up with.

it did do somthing new today. it actually died on its own while just idling, and the engine was still cool. it sounded like it was straining for fuel and choked, so its looking more and more like fuel issues. especially since it has yet to throw a code since replacing the opti.

 

Run codes on the car.

If you are around the central coast of CA, I'll let you borrow my ALDL cable since you have a 95.

Good luck and kill Rustanks!!!


x01660

 

well i just got done testing fuel pressure. it sat around 41 psi, and even on a full load with it taped to the windshield it hardly moved, maybe around 5 psi differance. went ahead and tested the fuel pump relay just in case and that was fine as well.

BUT i did however find out after double checking everything with a noid light that im not getting spark! I do know that the icm, coils, plugs and plug wires are good and not corroded as i just replaced and tested those. i was checking the connector to the opti and while im tracing it i find a very small amount of coolent slowly seeping out of my water pump. so i now have a gut feeling that it has leaked into my distributor.
but is it possible for the opti to go bad and not present any codes?

 

Yessir it is.

It might throw other codes

See my thread here:

https://camaroforums.com/forum/lt1-l...p-61557/page2/

Post # 12. (Dramatic, I know, but I was on the side of the road...)

But that does not necessarily happen. But if you said that you had leakage, then you might be SOL. Also see here:

4th Gen LT1 F-body Tech Articles

Let us know how it goes.

Good luck and kill Rustanks!!!


x01660