Xiantyl

So I've been searching for a while regarding my issue, my name is cameron I've owned three different lt1 based vehicles and quiet frankly I'm stumped , I have a problem where if its really hot outside and I drive for say 15 minutes I'll start getting a bad misfire at 2k rpm , not sure of the cause. Car runs perfect for hours when its not too hot outside . Opti was replaced 8k miles ago and so was icm and plug wires also new plugs. It's a 95 z28 6 speed , any info would help me

maybe2fast

can you be more specific on the temps you are having issues with? like 90* is bad but 60* is ok. My first thought is coolant temp sensor but I am not sure they are that sensitive to outside temp once its warmed up

Xiantyl

90 degrees is where it will start to misfire alot , and it throws a ses light sometimes lol could a bad maf cause this

DelSoto

If the ses light is coming on then you should be able to read any codes being set. Please refer to this link for Scan9495:

https://www.camaroz28.com/forums/lt1...bs-srs-874325/

Heat related issues like you describe usually scream either opti or icm. You said they were both replaced. Did you use a quality delphi unit? The knock offs are known to be poor quality. Of course, without a scan, that's taking shots in the dark.

Xiantyl

I Dont have a laptop to use for freescan yet so I guess I'll wait until then and yeah I used a Delphi unit off amazon and a Borg warner ICM :c

timnfxr

Did you use thermal compound between the ICM and the heatsink? It would've been a good opportunity to space the coil bracket from the head. It's not uncommon for the ICM to become heat soaked and cause erratic ignition problems.

Xiantyl

Its already spaced and yes I used thermal compound between ICM and heatsink. I changed it like 7 months ago and the problem only began a month ago

DelSoto

Post up the link to the opti you got off amazon. All I see is the knockoff junk.

Edit: Nevemind...found it.

Xiantyl

I've had the opti for a few months though and wouldn't it misfire in cold weather too if it was that ?

shoebox

Electronics are more prone to fail or act up when hot.

Xiantyl

Should I try replacing ICM first ? I have a lifetime warranty on it

DelSoto

I cant say that I wouldn't give it a shot. Then invest in the cheap cable. Borrow a laptop. Download the free software. Scan. Profit!

Xiantyl

Waiting for payday to order the aldl cable

DelSoto

Xiantyl

So new icm still same issue lol , starting to think it's my optispark , could changing just the cap and rotor be enough since I have nk SES light ?