Cobra cutting out at wide open throttle

[1Bad04Mystic]

I have been searching the forum for a little while, and I have been unable to come up with a solution. The Cobra in question has full exhaust, 115mm throttle body, 2.8 upper, steggy stage 4 ported blower, stock injectors, stock fuel pump and a kenne bell BAP. The car was tuned by Bob Kurgan, who unfortunately is now halfway accross the U.S. with an Xcal 3. Recently the car likes to hesitate badly during Wide open throttle applications. I thought maybe I blew the fuse on the BAP, but I just checked it earlier and it's fine. It is the 40Amp BAP. I turned the key a few times to see if I could hear it kick on, but I'm not sure if all I am hearing is the factory fuel pump. I could have swore I could here the BAP running, but it's been awhile since I have paid attention at start up. The car idles just fine and drives great, but at WOT it feels like it's missing bad. It almost feels like the car is holding itself back. Do you think I'm running lean, and that's why it is falling on its face? The car does have NGK TR6's that are pretty new. Any ideas? This is definitely irritating the shit out of me.

 

[04cobradude]

sounds like you need new plugs and gap em to about .028

bob kurgan

 

[GoatSlayer]

Check your injector plugs, sometimes they tend to come loose due to engine vibrations.

 

[03cobra#694]

and when was the last time you changed your fuel filter?

 

[1Bad04Mystic]

Thanks Bob, Ill check the plugs when I get a chance, the fuel filter is the stock one, the car only has about 7,400 miles on it.

 

[Coyote 5.0]

If your car is an 04 with 7400 miles on it I would definitely change the fuel filter. Especially if the fuel you use contains 10% ethanol.
In the OLD DAY fuel pickups had a filter sock on them that would get dirty and colapse under WOT

 

[1Bad04Mystic]

If your car is an 04 with 7400 miles on it I would definitely change the fuel filter. Especially if the fuel you use contains 10% ethanol.
In the OLD DAY fuel pickups had a filter sock on them that would get dirty and colapse under WOT

Unfortunately 10% ethanol is about all you can get around here. I haven't changed a fuel filter on a 03-04 Cobra, do you have to drop the tank to get to it?

 

[03cobra#694]

Unfortunately 10% ethanol is about all you can get around here. I haven't changed a fuel filter on a 03-04 Cobra, do you have to drop the tank to get to it?

No, but it's a pita, hard to get both your hands up there. Make sure you have a descent disconnect tool

 

[cobra=trouble]

does it lay down or not rev over 5200 rpms ?

 

[1Bad04Mystic]

It lays down when you get high up in the RPM range but only at wide open throttle. I'm going to change the plugs later on today and see if this fixes the problem first. It's not like when people talk about the pprv, when you let off during hard driving. This is when you mash the pedal. In about any gear

 

[Coyote 5.0]

Unfortunately 10% ethanol is about all you can get around here. I haven't changed a fuel filter on a 03-04 Cobra, do you have to drop the tank to get to it?

http://www.svtperformance.com/forums/how-230/260804-fuel-filter-change-writeup-13-pics.html

good info

 

[1Bad04Mystic]

Just changed the plugs and oil, and took it for a spin. Runs like a champ up top again! I can't believe the difference it made! Thanks for the advice Bob! I did buy a fuel filter as well, and will be changing it in the near future. Thanks for the write up info Coyote 5.0!

 

[Blueline]

Glad you got it all worked out! And thank you for posting your end result / fix..

 

[Coyote 5.0]

Oh yeah! glad you got your baby running smooth again.

 

[1Bad04Mystic]

I wish I would have changed the plugs sooner, feels like the first time I had it tuned after the ported blower. Now if I just had the money for a Whipple or Kenne Bell...

 

[SonicBlueOval]

Did it pop at all when you mashed the throttle? Mine is doing a similar thing at WOT, but it also pops really bad so I let out. If I accelerate slowly through the RPMs it is fine. I know I am running a little rich (waiting for wideband next week before I change tune), but Im wondering if I have the same plug/gap issue you had. I am running autolite iridiums though

 

[SonicBlueOval]

Nvm, went out today and decided to regap the plugs. Took it out for a run and it screamed. Amazing what the right plug gap will do

 

[1Bad04Mystic]

Nvm, went out today and decided to regap the plugs. Took it out for a run and it screamed. Amazing what the right plug gap will do

Nice man, I run the NGK TR6s. Sometimes it's the little things that get overlooked

 

[SonicBlueOval]

I probably should have gone with the TR6s because so many people use them, but I decided to go autolite iridium. Since I went iridium I gapped them bigger than what most people do with the copper plugs, but I put them at . 038 and everything is good now.