cdngolfer

Guys

I need your help

I have an 08 Z06 with a medium cam that was installed a year ago with dyno tune. New double springs were installed too.

This spring I had a miss in the engine while running Mosport. It was traced to a loose ground on the battery terminal. Fixed

Since then I occasionally get a an engine miss at higher throttle and at lower RPM driving around town that feels the same. Also when I fill it up with 94 octane, my range dropped to 370 kms from 490 and my mileage indicated is down about 20%. I have put in 2 or Techron bottles to no effect.

Its not a consistent miss and comes and goes. The check engine light comes on too for about 2 to 4 blinks then goes away. There were no codes thrown back in the spring.

Any ideas? Fuel injector, coils, ECM?

c5racr1

Plugs, wires, dont use anti seize on the plugs. Headers? If so would go to the wires, I have seen headers kill wires and you couldn't tell from looking at them. Do you have scanner that will show you the history? You probably have stored codes that will help

cdngolfer

Thanks

I had the plugs pulled at the track in May and one header did contact the boot but had done so for 3 years prior. I did not know that the wires could go bad at 25 K miles with no visual. It would be the simplest reason and quite likely. I will buy new wires as its a cheap try.

c5racr1

Get a cheap set of wires and some heat boots and try it before you go expensive. I bet that solves it.

cdngolfer

Thanks

I will order them today.

And check the ground bolt on the heads. They were redone with new valves last year

acroy

+1 plugs, wires.

Mine looked fine till I was working on the AC, engine running, and noticed cyl6 sparking to the dipstick tube! Well, that explains the stumble at idle...

A nice set of Magnecors, and the engine is much smoother

Check grounds & main harness plugs as well

cdngolfer

New plug wires = no miss no more!

Thanks guys!

Speedforhire

I'm curious! Were you getting a P0300 code - Random Misfire Detected?

My car is doing this now; post cam install. :-(

cdngolfer

In May when the problem first surface, no codes were detected. I did not have them checked since. I put new plug wires on last week. One boot had been burned by contacting the header on #1 cylinder but it had been that way for 3 years with no problem. I guess the insulation broke down after 3 track days.

I cam will create more HP = more fuel = more heat in exhaust

Speedforhire

I put new MSD wires on and it continues to throw the code. The plugs are the oem ACDelco units. I have a set of TR5's, but I haven't installed them.