Engine cuts out at 4K WOT???

[Soon2beBlown]

It seems everytime I bring the rpms up to 4K rpms no matter what gear I'm in the car cuts out totally. I mean full loss and it won't rev again until I let go of the throttle and then get back on it. It dones't seem like the clutch is slipping because the rpms will stay there at 4K but make no power. I originally thought it was the clutch because I recently installed a wet shot of nitrous and I'm sure the stock one wasn't going to hold up too well. I went with the king cobra clutch and now even NA it does it everytime I hit 4K. It seems as if its hitting the rev limiter but its not even near that. Any input on whats going on is greatly appreciated!

 

[RYC CUKR]

Check your fuel system.

I had a pump go out and it would not rev or make any power past 5k. It gradually got worse. Took it in and sure enough the pump wasn't putting out enough fuel to feed the motor at higher RPM

 

[mooktank]

Same happened to me. Get a fuel pressure gauge if you can.

 

[HISSIN50]

It can also be a TFI on the outs.

Good luck.

 

[90mustangGT]

Had the same issue with a 4 popper mustang, turned out to be a dirty MAF.

 

[Daggar]

Random thoughts on possible causes:

Spark is being blown out (too much gap or not enough juice to ignition system, also check charging system)

Vac leak (unmetered air is entering motor)

Clogged fuel filter or fuel pump falling on its arse (can also be directly related to charging system voltage)

 

[Soon2beBlown]

I'm thinking its the spark being lost. I'm running the coldest plugs that autolite makes because of all the n2o I'm running. The ignition system is stock otherwise. I tried making my gap even smaller and its doesnt cut out until about 4200 RPM now...a small small improvement but I think that defined my problem. Will simply upgrading the coil to an MSD unit give me enough juice for the time being? I have the opportunity to dyno my car this weekend so I want to alteast be able to bring the revs up to 5k or so.

I don't think its a vacuum leak...I'm pulling about 18-20#'s at idle. Although I am having problems keeping my PCV grommet in there.

Also the fuel pump and fuel filter were both replaced around 15K miles ago so that shouldn't be the problem.

 

[black92gt]

I have the EXACT same problem with my coupe. Try yours at part throttle, mine will rev past 4, but not if I make any boost. Not sure if it is the spark problem, or the fuel pump problem. Mine has been getting worse and worse, I guess the pump will eventually take a crap. Just my two cents..