Loss of power at WOT

[FLSVTCobra]

I have posted this question before in the SVT section but didn't get any responses so here we go.
My 96 Cobra has an issue while accelerating at WOT. When I get to about 5000 rpm or higher the car bogs as if I just hit the rev limiter or the car has run out of fuel. Other than that the car drives fine, the only thing that I need is a new alternator. Could this be the problem?

I have already replaced the spark plugs, fuel filter, and cleaned the IMRCs and the MAF.

My current mods are: full exhaust, C&L maf, intake, build bottom-end, 4.30 gears, short shifter, egr delete.

Any suggestions will be greatly appreciated.

 

[cobra2798]

Maybe the Fuel pump is cutting out up top? I dont know how you would know but you may want to check that.

 

[ADRENLN]

actually i think alternator and battery can do funny things up top too if they are not in good running condition....not sure though. i know that can be a problem on a blower car but not sure about na

 

[Silverstang02GT]

My car had a bad miss for a wile and could not figure it out. replaced the COP's, plugs and moved the injectors around to see if the miss would follow. no luck the miss was random on random cylinders and through the whole RPM band. even though the gauges were showing proper charging I replaced the alternator and it cleared up. Talked to a Ford tech and he gave me the ideal it could be the alternator

 

[4tun8]

Does it sound like it's hitting the limiter up top? It's probaby the coil packs.

 

[FLSVTCobra]

It feels like it is starving for fuel at higher rpms. It pulls really hard up to about 5000 rpm or so and the it bogs down, kind of like hitting the rev limiter. Its only at WOT though.

 

[crazystang25]

i have the same prob and i checked on my tuner and my fuel rail pressure kept dropping down between 1-7 psi so i replaced my fuel rail pressure sensor and it was still doin it and so i went and did some more data logging and remembered before all four of my o2's were reading about between 2-4v at wot. and then it through up a couple codes and so i went up to the ford dealership and he said bad bank 2 rear or bad maf sensor.

 

[genericusername]

Same problem here - found a cure

I have an '04 Mystichrome Cobra with a Whipple-charger and a bunch of other goodies. Last week, my car started losing power at 5000rpm at WOT. Today, while cleaning the trunk, I noticed the cable for my boost-a-pump was disconnected. Plugged it back in and it cleared up the problem. So if you have the KB BAP, you might want to look for a short or disconnect.

Hope this helps!

John
Sacramento, CA

ps. The reason I joined and posted is because this forum is where I went to figure out why my 'stang was starving at WOT. Good luck

 

[jgorm]

I have an '04 Mystichrome Cobra with a Whipple-charger and a bunch of other goodies. Last week, my car started losing power at 5000rpm at WOT. Today, while cleaning the trunk, I noticed the cable for my boost-a-pump was disconnected. Plugged it back in and it cleared up the problem. So if you have the KB BAP, you might want to look for a short or disconnect.

Hope this helps!

John
Sacramento, CA

ps. The reason I joined and posted is because this forum is where I went to figure out why my 'stang was starving at WOT. Good luck

Damn, your nuts to run a car like that without a wideband!! For the OP, you can try logging the O2 sensor volts to see if its going lean, or install a FP gauge, or a wideband if you plan on more mods.

 

[GettinThere]

My current mods are: C&L maf...

Do you still have your old maf sensor?

 

[GDawg]

I don't want to become known as the "AC Ripple" guy... but check it. If your Alternator's diodes are going bad, it will mess with your computers, hence, car not running correctly.

 

[trinity_gt]

I don't want to become known as the "AC Ripple" guy... but check it. If your Alternator's diodes are going bad, it will mess with your computers, hence, car not running correctly.

LOL. I knew you were going to say that.

 

[GDawg]

LOL. I knew you were going to say that.

It seems like everyone is having this problem right now...

 

[trombonedemon]

My bet is the fuel pump. Does it do it with a full tank of gas, if not, its the fuel pump!!!!