well it's an idea I reckon. I'm headed to my friend who has a shop and offered to diagnose it for free...but it just really chaps me because I like working/diagnosing my own stuff. I'll post any results and see if he has the logging ability with his computer setup.

 

Where in texas are you? see if you can hook up with someone with and OBD! conversion and swap PCMs to see if that works

 

I love beating dead horses!!! It's brutally fun!! Nah, j/k, lil late-night humor. I believe your list of suspected culprit parts did not include the ESC...(electronic spark control module)...That little booger set 3 different codes on me back last summer including the infamous Opti codes. In case you're wondering where that is...it's the little black box on the aluminum heat dissipator that your stock coil is connected too. Now, the wiring and mounting varies from year to year but after many-a headache I found that spacing my coil away from the head and relocating the ESC (also replaced it) along with the cooling fins over to the driver's side inner fender made all sorts of problems go away for me and at least a half-dozen other people. It seems that as that little piece gets older it becomes more and more susceptable to heat...In fact, when it's @ temperatures too hot for you to hold (it reaches these in normal driving) it tests completely different on the multimeter that it does @ lower temperatures...especially under 120 degrees farenheit. Above these temperatures the signal it provides becomes "grainy" and does not send as clear a message to the PCM about firing parameters. That last part is a guess @ what's going on but I know the signal becomes distorted. Aside from that, I'd look into some good dielectric grease, checking EVERY plug gap, the continuity of the wires (40-60ohms PER FOOT) for a performance wire, space the wires, make sure they aren't near the ABS wires (yep, had that problem) and then come back here...let us know if you need anymore suggestions....we'll run you rampid

 

having same problems...TTT

 

Well... let me pipe in here by saying that I've not chansed this demon like others. Simply, because I've never "really" felt it.

I feel, that the ICM spacer trick is indeed brilliant, and something to consider.

However, I run my wires over the valve cover (dramatic reduction in heat the wires now see), with MAC headers. This doesn't necessarily help the stock manifold guys.

Might I suggest running the TR6 plug, and trying out what a lower heat range plug does. You can try at the .035 gap it comes with, or gap it at 0.050. My thinking was that the heat of the engine was simply, causing the stock plugs to turn into glowing embers.

Something to consider.

 

I posted this before in the general discussion and I am still having problems, so here it goes for the last time. Please help! I am replacing parts and getting nowhere! I have a 1994 z28 that is missing and hesitating after I drive it for about 20 minutes and it gets hot between 2-5 grand. I am not getting any codes at all! When it is hot and we put it on the scanner, the sensors all come back normal. We removed the first two injectors and it made no difference in the running of the car. We put a node light, and it did show current to the injectors. So one mechanic now says to replace all of the injectors. I have stumped three mechanics. I have replaced the following:

coolant temp sensor
opti spark
fuel pump and filter
plugs and plug wires

Any help would be appreciated. I have know stumped three mechanics, and they are still guessing. Thanks guys

 

A log would be good ie datamaster.

 

did u ever replace the bad injectors?

 

I had the exact same problem a couple of weeks ago and I replaced all kinds of stuff, In the end it was my #5 plug wire. I would double check to see that none are near your headers. I didn't think it was wires cause it would only miss after warming up. I was getting no codes either

 

I'l merge this with another thread on the issue-