Power Cuts Off at higher RPM

[Mcgee16]

First i have a 95 gst 5- speed. It has an intake and Greddy type-s bov. The car has normal power until about 4000 rpm then just takes forever to rev to redline. If i keep on the gas it will hit fuel cut-off (not redline)then keep reving. I pulled the spark plugs and there very black. So that is telling me that its running rich. I have good vaccum at like 18-20 at idle. Cold like 15. Im thinking that it might be an o2 sensor but wanted to ask for help first. Tomarrow i'll build a boost leak tester.

Thanks
Scott

 

[92redman]

I've been having similar problems on my N/T for a while. I have ECU problems I am trying to fix now, but basically under hard acceleration I would "hit a brick wall" at around 5,500 RPMs and it would scare the shit outta me so I would shift fast before it even had a chance to rev higher.

 

[IHeartTurbo]

Originally posted by Mcgee16
First i have a 95 gst 5- speed. It has an intake and Greddy type-s bov. The car has normal power until about 4000 rpm then just takes forever to rev to redline. If i keep on the gas it will hit fuel cut-off (not redline)then keep reving. I pulled the spark plugs and there very black. So that is telling me that its running rich. I have good vaccum at like 18-20 at idle. Cold like 15. Im thinking that it might be an o2 sensor but wanted to ask for help first. Tomarrow i'll build a boost leak tester.

Thanks
Scott

how can u keep accelerating after fuel cut? i know i cant.

 

[Mcgee16]

It shuts off then turn right back on. Im just wondering if my MAF or o2 sensor is messed up and tricking the ecu. Fuel cut-off should only occur if its running to lean, but my spark plugs show a rich condition.

 

[92redman]

Haha, swapped in my old ecu again, and it wasn't fuel cut. Turns out it was the ecu reseting at higher rpms, runs fine all the way to redline now. Until it starts misfireing again