I've just put a new wiring harness in my KITT project, along with a performance 4L60E transmission and 2400 stall and I'm having some problems.
After pulling the engine I found my plug leads were melted and replaced them all, and found cylinder 5 had not been firing at all by the looks of the cylinder.
Anyway long story short, everything should have been all good, but I'm getting some intermittent popping from the exhaust at idle, part throttle and mid throttle in park.
I haven't driven the car yet as I'm hesitant to do anything to cause damage.
From what I've read, the popping is unburnt fuel combusting in the exhaust pipes so I'm left with the following assumptions:
Leaking injector, too much fuel getting in the cyclinder and getting blown out with the exhaust.
Coil/spark plug not firing. Fuel goes out the exhaust.
Timing off - fuel going out the exhaust
The less common and stranger ones I've seen is an exhaust leak allowing air to get into the exhaust and cause the popping, but I would have though an exhaust leak would have positive pressure in the exhaust and would only expel air....?
My vortec dizzy used for the cam signal is possibly out of sync, but the car fires up first go and the idle is pretty smooth, so the idea of a leaking injector seems strange.
On one scan I saw the bank 2 o2 sensor jumping all over the place on a gradual downward spiral to about 150-200mv, which if I read it right tells me it was getting very rich.
I also had the exhaust pushrod on cyl#8 come loose when the locknut on the rocker decided to let go, but I checked the lifter rod and rocker and there was no damage just a loud tapping noise until i fixed it. I'm now wondering if it's possible if the exhaust valve not opening if the pressure has pushed back into the injector and damaged it?
My plan at the moment is to remove all the injectors and get them cleaned and flow tested to eliminate that as an issue.
Then probably pull the plugs on that side and see if I find a wet one to determine which cylinder is causing the pop.
Any other ideas or starting points?
I'm still very hazy on the cam signal/dizzy signal for a 24x system. I know it is used to tell the PCM whether the engine is on combustion or exhaust stroke, but does it need to be very accurate?
Can it cause these sort of issues if it's out by a significant amount?
I've logged the Cam offset but it reads about 3-4 degress under 1000rpm and 2 degrees at 1100rpm. I'm assuming at that rpm it just maxes at 2 degrees but I haven't had a chance to play and move it around yet while the car is running.
Any suggestions are appreciated.
Thanks.
P.S
I'll upload the log when I get home from work which might give one of you HPT rainmen a better idea of what's going on.
Here's the log along with the channels i was logging.
Wideband isn't wired up to the logger through EGR yet, but watching the gauge it looked ok for the majority of the time.
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