Hi folks,

Recently finished putting my car back together after a major rebuild (body work, paint, air ride, shaved engine bay, clutch, flywheel, vortech install, CJM return fuel system, new fuel pump, etc, etc). I downloaded the UpRev base map rom my tuner provided to me on the ECU, car fires and idles, runs and drives but I have a pretty mean misfire.

Using Cipher's cylinder tester function I was able to determine that cylinders 3 and 5 were not firing.

I swapped coil packs around, swapped plugs around and confirmed the coil packs and plugs were all OK.

Verified +12v at the coil packs for cyl 3 & 5, also have ground on the black wire at the coil pack.

My multimeter does duty cycle and RPM readings. I was reading an RPM signal with the car running at idle on the signal wire @ coil pack #3. Not sure if this was a 'good' signal, or just induced noise..

Still no spark on cylinders 3 & 5.

Any ideas what to check next?

Everything else seems fine, just getting code P0300 random misfire I think it is.

 

Im betting you have your harness wrong just like I did. Swap #3/#5 coil pack harness. Loom at the couple of pages in my build thread!

 

I was just thinking that actually... Going to go check right now.

The plugs in 3&5 looked clean and wet though, like they had never fired.

No noticeable change in how the car is idling when I disconnect 3 or 5 either.

 

Boy do I feel dumb lol..

Checked the wire colors, and sure enough, had 3 & 5 reversed.

 

Lol. Glad you got it sorted

 

Just waiting for the battery to charge before I try to fire it again.. I think this battery it pretty much effed.

 

:-) I did the same thing so no harm no fowl!

 

New battery and car purrs like a kitten now!

Put 120 miles on it last weekend. First time driving the car in 2 years since it's been off the road getting modified.