i have 95 lt1 a4 mods: ls1 lid LT headers tune 1.7 rockers
so the car starts and does idle but has a misfire at any time and does become more noticeable and happens more often once it gets warm. sometimes it does get so bad when I press the gas it wants to die
everything replaced:
icm, coil, plugs also see no arching of the wires at night
opti is pretty new (Delphi)
on the laptop the o2 fluctuates from 50 to 1000 so they are working and the coolant sensor is reading correctly and picking up no knock
now I did pick up a fuel pressure tester and when priming it only goes up to 38lb and even if I prime it a couple of times it barely raises, at idle it stays at 32lb and fpr is good
and I have tried adjusting rockers but that made no difference either
i think it's either fuel pump or opti on their way out any suggestions or similar experiences
and yes I have done research of other people's problems but looking for some new input

 

Are there any indications of leaking coming from the Optispark? Any oil or coolant spots underneath the car? I have gone through too many optisparks due to the shop's improper installation or improper water pump installation.

Have you double checked that the spark plug wiring is correct and made sure there are no burned wires on any exhaust components? You may not see any arcing but I had one wire that was melted on my newly installed shorty headers, thanks to the morons at the shop who put in my remanufactured LT1.

The ceramic cover on a spark plug may have cracked and you are arcing although you don't see it.

Is your crank sensor functioning properly? Maybe it's the reluctor ring?

These are just some of the ignition problems my car has had over the years that you may be suffering from as well. I hope this helps.

 

What I'm afraid of is I had the annoying intake manifold leak and I had it fixed once by a mechanic but either the surface wasn't cleaned or wasn't torqued down properly because it leaked on the front and back of the intake afterwards so that oil could of drained down and then I had a strange event where my power steering pump or lines shot fluid out and got all over so that could of soaked it also.
For burnt wires do they have a consistent miss or is it more random because my car will idle fine for 5 to 10 sec miss then may miss in 4 seconds or 20 it's very random and then sometimes will miss like crazy and act like it wants to die

 

I have had mechanics shops with terrific reputations and which came well recommended, screw up simple things on my LT1. I had a Jasper remanufactured motor put in over a year ago and these "professionals" gave me my car in a random misfiring state. I had to take her back and I received the car with a major exhaust leak. I had to take her back and these guys argued it was just my shorty headers I had them put on, but it was an exhaust leak none-the-less. I got her back and the car computer died on me. I sent her back and eventually, after all their "professional" screw ups to fix my header exhaust leaks, the repeat improper installation of my water pump or distributor which lead to premature failure from oil or coolant pooling in the unit, and other bizarre electrical crap going on with my car, I finally found a shop that did me right and fixed the other issues that I would not allow that other shop to correct on my car, again! After I am done getting my degrees in college for computer science, I am really considering going back for an associates in automotive technology, just to be able to do more on my car than what I am already able to do. I don't screw anything up when I work on her! I even fixed a secondary exhaust leak at the bottom of my driver header flange which those morons never even bothered to slap on a new gasket, five bucks at the auto store!

For burned wires, the results can be sporadic. My wire was grounding out on the header and the misfiring just started happening when the cover was totally melted and my car was misfiring and bucking like a bull! It scared the hell out of me and I damn near thought I broke my motor! On the contrary, when I discovered a shorting out spark plug due to a broken ceramic cover, the car had random misfiring and it would hesitate under high load, but low load you wouldn't notice anything was really wrong. It had slight sputtering at idle but it got worse with higher RPM. Oh yeah! I had similar problems with bad optisparks, it could be just a bad unit or it could be improper installation and there is some coolant or oil collecting in the unit. It is not so easy to diagnose misfiring on our cars. However, this is what I have experienced thus far!

 

Alright if anyone now has any new suggestions new opti and new racetronix fuel pump. The car doesn't misfire as soon as you start it anymore but wasn't its warmed up, also my car is idling high after first initial start up it idles normal but once I drive it and through it in park it stays at 1200 and won't go lower. Injectors compression? Anyone?

 

Could it be something as simple as a cracked spark plug? I spent money on new spark plug wires, a new ignition control module, a new ignition coil, replaced a good working MAF, replaced my MAP sensor, and I even swapped out my crank sensor trying to track down a minor misfire with my car, and that whole time it was ONE arcing spark plug with a cracked ceramic cover! Have you checked the spark plugs to make sure there are no cracks with their coatings?

Also, is this misfiring really bad or is it mild? You can throw new parts at it all day and it might be the most basic and cheapest part that is throwing off your ignition system.