87bandit

man you got a pretty ****ty attitude for a guy asking for help

87bandit

because when exposed to heat or extended use, failing or old electronics are more likely to show problems

95Blackhawk

Bandit,

90% of my posts are helping other people. I read tremendously before I ever ask a question. Sorry you take my frustration as "****ty attitued". It is trying to get to a solution.

Do you have something to add to the situation? I am very willing to hear it.

Ben

95Blackhawk

I am willing to consider this. However, the problem is so specific to temperature, I would consider it less likely. The reason being is that variances in air flow will affect the final temps wiring will see outside of the block but electrical, etc. attached to the block will be more likely to be affected on a more specific basis.

94CamaroZ28/SSClone

Thanks for addressing the attitude. I also felt, like you were giving some attitude.

87bandit

have you scanned the car while running it? is this a problem that will disappear if the temp drops below 195 or does the car have to shut off and completely cool down and sit?

I am wondering if this is a closed loop/open loop problem as opposed to a specifically temperature related problem, unless that is something you have already looked into where you've experienced the problem in both open and closed loop.

also is this an issue that has existed since the completion of the setup or something that developed over time?

Injuneer

Is it possible you have a fuel line too close to the exhaust, and the engine/exhaust heat is causing the fuel in the line to vaporize? While fuel flow/pressure isn't directly related to engine coolant temp, the longer the fuel pump runs, the hotter is may be getting. Couple hot fuel, brief pressure losses, with a line too close to the hot exhuast and it may be vapor bubbles. The brief pressure losses might not show up as visible drops on the fuel pressure gauge.

95Blackhawk

Just get below 195 and the problem goes away.

I like the idea of shutting off and then running before the car has had a chance to start using the O2 sensor. It is worth a try.

"I think" this has always been here but not sure since I have been working on so many problems with the car for the last 2 years. This is like the final issue that must be resolved.

95Blackhawk

This is a new thought.

Yes the exhaust is within about 6 inches of the fuel lines for a foot or more. It will be easy for me to wrap the fuel lines in high temp tape and try this scenario.

TheGreatDane

likewise

My first thought was ICM taking heat from the heads. My noob suggestion would be the washer trick, and zip-ties galore.

The fuel vaporization theory seems plausable. I've seen it happen to Beach Bonanza aircraft engines during the 100'+ weather in TX. Even with 100LL Avgas...

95Blackhawk

Done it

Thanks for trying to fill in some knowledge gaps. Next was actually to move the ICM and coil to the fender to totally keep it away from the heat but something tells me after 3 ICM's and NO change in status of the problem it is not the ICM.

TheGreatDane

How about the cable routing?

What a bummer. I feel for ya though. Sucks when ya can't figure it out. Have ya googled your problem?

95Blackhawk

Engine harness routing is the same as a stock F-body. All other wiring has been changed in the last month that would impact ignition and no change to the condition. Oh yeah...hours upon hours of google and some interesting things come up to try but no solution.

Based on the discussion here, I come to 4 possibilities:

MUST USE AC Delco opti only (maybe the multiple Autozone remans just can't do it)

OEM Engine harness wiring from PCM to ICM is bad

OEM engine harness wiring from Opti harness to PCM is bad

Heating up fuel from exhause before it enters rails


You are welcome to throw others into the mix.

TheGreatDane

Try the advanced boolean search parameters on google. Copy the following to google exactly as appears here with all punctuation. It should yield more relevant results.

LT1 "high rpm" (miss OR skip OR misfire OR stumble OR hesitation) "when (hot OR warm)"

jasonface

Just throwing this out there...
Is it a hydraulic, or mechanical cam? Years back I saw a guy adjust his solid lifters a hair too tight. Car would fire up, but as soon as it came up to operating temp the valve train expansion would hold a few valves open....just very slightly, causing a miss. Slight miss on some cyls, bigger miss on others. As soon as it cooled, the problem went away.

Figured you might have swapped in a solid roller, based on your other mods. Good luck. And yes, from what I'm learning, stay away from AutoZone Optis...and Acell...and ANY aftermarket ones on eBay.