Need you geniuses again

[04Cobra550]

I've had a problem since late last week. The car drives normal, idles fine, but as soon as you give it more than 75% throttle, it stutters and sounds a lot like it does when the traction control kicks in.

It seems to have normal power until you go into a hard acceleration, then it stutters and barely accelerates - sometimes with a sharp cutoff for a moment.

I've replaced the fuel filter, spark plugs, spark plug wires/boot, cleaned the MAF, and checked the fuel pressure. The fuel pressure runs at 30-34 PSI at idle. No error codes are being thrown.

Any ideas?

 

[03SonicVert]

Have you checked battery/charging voltage? Does the charging light come on when this happens?

My guess would be alternator then maybe look at the FRPS.

SV

 

[04Cobra550]

I checked the voltage while driving, it stays around 14v at all times. Any other thoughts?

 

[hotcobra03]

coils

they get weak but not enough to give code...

suggest you look for a set of 8 to try for testing first...

and fuel pressure? how did you test it?

 

[Blueline]

Check your ic pump along with your iat2 temps?

 

[04Cobra550]

Thank you so much for the replies. I'll try a set of coils, just placed the order as no one had them in stock around here.

I tested the fuel pressure with a fuel pressure gauge while idle, then with the Predator tuner. Both came out to ~30PSI. I'll test it under load today and post up the numbers.

Probably a stupid question, but how do you go about checking the intercooler pump? Is there a fuse I can pull and put back to hear it kick on, or is there a way to test the pressure?

 

[LS1toSVT]

You should see the fluid circulating around in the reservoir. I can't remember if its on all the time or only after a certain temp is reached tho. I'd imagine after the car is up to temp it should be on.

 

[mws221987]

could have a bad FUEL PUMP , I had a fuel pump go out and it did the same thing .

 

[hotcobra03]

Thank you so much for the replies. I'll try a set of coils, just placed the order as no one had them in stock around here.

I tested the fuel pressure with a fuel pressure gauge while idle, then with the Predator tuner. Both came out to ~30PSI. I'll test it under load today and post up the numbers.

Probably a stupid question, but how do you go about checking the intercooler pump? Is there a fuse I can pull and put back to hear it kick on, or is there a way to test the pressure?

I use predator..39 I get on mine..38-40..

They say it goes up under boost ..depends on how and where test is done..

Are you sure you put fuel filter in proper direction?

 

[04Cobra550]

Update: It turned out it was bad gas. Siphoned some out and had it tested, there was way too much water in it. After some HEET and diluting it down with good gas, the issue went away completely. Thank you all for the help!

 

[SickBlackMach]

Glad you got it figured out! When I lived in Cali, I had a list of what gas stations I was OK with buying gas from. Had this happen to me a few times and hated it.