No rev past 4300.

[RL7]

There's really not an excessive amount of stress placed on the ignition system while reving in neutral. I would be more suspicious of fuel delivery than spark plug gap. Hop under the hood and hit the throttle with your finger and see if fuel pressure dips where you cut out.

[Blurr]

This might sound like a stupid suggestion but having gone through the same thing you describe (and having gone through the same electrical, ignition, timing, and fuel troubleshooting work trying to figure out it), my main cat was clogged and I couldn't get over a certain RPM while driving but it would free rev fine.

I felt like an idiot because it was so simple. If you have cats, check them if you can or simply drop the exhaust.

Edit: I even went so far as to sit on the engine and hold on for my life while my friend drove the car and I watched the on rail fuel pressure gauge. I was seriously running out of options. When you're willing to die to diagnose an issue, you know you've got problems...

[Mean Green]

There's really not an excessive amount of stress placed on the ignition system while reving in neutral. I would be more suspicious of fuel delivery than spark plug gap. Hop under the hood and hit the throttle with your finger and see if fuel pressure dips where you cut out.

I just purchased a new Vacuum / Fuel pressure tester the other day and haven't had a chance to use it. I will actually go buy a fitting for it this morning.

This might sound like a stupid suggestion but having gone through the same thing you describe (and having gone through the same electrical, ignition, timing, and fuel troubleshooting work trying to figure out it), my main cat was clogged and I couldn't get over a certain RPM while driving but it would free rev fine.

I felt like an idiot because it was so simple. If you have cats, check them if you can or simply drop the exhaust.

Edit: I even went so far as to sit on the engine and hold on for my life while my friend drove the car and I watched the on rail fuel pressure gauge. I was seriously running out of options. When you're willing to die to diagnose an issue, you know you've got problems...

lol..yea you where desperate but I am not so much anymore as I have so much interest in the car. Some people want it as is. I also do not have cats anymore, they're gutted.

[Mean Green]

Just confirmed the fuel pressure, it stays a little above 40psi the entire time. That now rules out fuel related issue's.

[CoreyB]

What pump?
what reg?

Normally pressure is about 43 ish with no vac.

That means that at idle with 20 inches of vac (about 10 PSI below atmospheric) fuel pressure should be about 33psi.

That's why my own car runs 2 stock regs with the walbro and idles perfectly with the 880s once warmed up.
If you had a datalogger you'd see the low fuel trim pegged out at min.
Is the vac line connected to the reg?

Steve

What do you mean by this ? I am confused by the use of inch's with vac and the statement that it 10 psi below atmospheric pressure which would be 4.7 psi or 10 psi of vacuum.

[Mean Green]

What do you mean by this ? I am confused by the use of inch's with vac and the statement that it 10 psi below atmospheric pressure which would be 4.7 psi or 10 psi of vacuum.

Yea, it confused me too.

I replaced the coils, the skip is gone but the rev limiter I guess you could say still remains. I did manage to log it and at 4600+/- the O2's are reading 0.00 on both banks. Still, if I floor the car 100% it does not have alot of power where as if I give it just a hair below full throttle it hauls ass. The fuel pressure reads just about 40 PSI when the car is off and 42/43 when the car is running and acting up. The idle vac is not 20, it's 17/18.

Now ignition is completely ruled out as well as fuel flow and compression. The ecu was tested in another car as well. I am running out of things to test and will be ringing out the harness from the ecu to each sensor again in hopes I missed something.

[CoreyB]

I know you said you replaced it but I would still test the TPS across the full band. I suspect that after a certain point of throttle it goes flat. You probably have logged proving me wrong already though.

[Mean Green]

What pump?
what reg?

Normally pressure is about 43 ish with no vac.

That means that at idle with 20 inches of vac (about 10 PSI below atmospheric) fuel pressure should be about 33psi.

That's why my own car runs 2 stock regs with the walbro and idles perfectly with the 880s once warmed up.
If you had a datalogger you'd see the low fuel trim pegged out at min.
Is the vac line connected to the reg?

Steve

Brand New OEM FPR

Walbro 255 hotwired.

My car runs great at idle when its warm.

I know you said you replaced it but I would still test the TPS across the full band. I suspect that after a certain point of throttle it goes flat. You probably have logged proving me wrong already though.

I'll check it again but yea, I got logs showing its fine. I did get a code 41 today but I don't know why, it was just a stored code that was not there yesterday.

I also had something odd happen today...while hooking up a fuel gauge for the inside of the car, I moved the harness around a little of course. After I finished, I started the car and it was only running on a few cylinders...I hit nudged the harness by accident and it started running on all 6 all of the sudden. I know that shit wasn't right and sure there is a dead short somewhere and I'll try to locate it tomorrow / today...lol..

[CoreyB]

I dont think its a short rather an open. The connectors on the ECU get shitty. If it was in the area you can pull the plug and look to see if all the sockets are in a condition to make good contact to the pins.

[Mean Green]

I dont think its a short rather an open. The connectors on the ECU get shitty. If it was in the area you can pull the plug and look to see if all the sockets are in a condition to make good contact to the pins.

I am going to be pulling the emanage off as well. It is just 0'd out right now with all the base setting's. I do not think that there is anything else I can do to the car mechanical wise or electrical wise....it drives perfectly fine unless I floor it.