Weird Issue

**Slick2500** · 12-19-2010

I already moved the injector when I replaced the o rings so I think that would eliminate the injector.

**matt5112** · 12-19-2010

Well then, I guess it is onto the ICM.

**Slick2500** · 12-30-2010

I just noticed that the vacuum line to the evap canister is missing that couldn't cause a misfire could it? And where the heck is the evap canister at anyway, I couldn't find it.

**gtpinsc** · 12-30-2010

evap canister sits behind the blower.. its pointless bull****... but id fix teh vac leak.. doubt its the misfire cause but i could be wrong.

**matt5112** · 12-30-2010

vac leak would make it run lean and could cause a miss.

**Austins01GP** · 12-31-2010

Something real similar to this happened to my friend just recently, he had a miss on cyl #5 and replaced everything and couldn't figure it out for a long time. It turns out in the end that his fuel trims were bad. We then Put the stock PCM back in an it ran perfect.

**Slick2500** · 01-01-2011

I have a stock pcm.

**GTPguy2000** · 01-01-2011

what kind of plugs are they,NGK is the way to go if not then delco are ok too,3.8s are picky bltches

**Slick2500** · 01-01-2011

Autolite ap606 iirk.

**Slick2500** · 01-11-2011

So I drove the car halfway across the state for work, then scanned it when I got home, now its putting up the code P0300 random multiple cylinder missfire. So I am more convinced that it is indeed a bad ICM.

**Slick2500** · 04-15-2012

Well a little update on this here is a list of things I have replaced/removed trying to figure out wtf is going on.

Checked 800 times for vacuum leaks
New Autolite 104's gapped at .055

New Premium Wires

Swapped out all the coils twice

Swapped out the icm twice

Removed the cat
Removed Egr
Swapped injectors around
Replaced all the orings
Replaced new Powerbond SFI Harmonic Balancer
Replaced Crank Position sensor

Still have random multiple misfires.

This screen shot is from the car idling after a 15 min cruise down the highway. I tried to get a scan but when I opened the file it was blank

**Slick2500** · 04-16-2012

Replaced Cam Position sensor today and still random multiple missfires........ that leaves only 2 more things that could be wrong the computer is bad or I have multiple chipped pistons.

**Slick2500** · 04-16-2012

Went for a cruise down the highway for about 15 min, and my Timing Advance is all over the place while cruising its anywhere from 0* to -29.5* LTFT1 was pretty constant at -8.53975% had a short blip for a few seconds to -7.8125%