Stock terminator falls on face in boost

[MaximusDecimus]

Hey guys, so I've tried figuring out this problem by searching/reading existing threads, and it seems a few people are having similar issues however most are inconclusive and have many other variables due to being highly modded/tuned that wouldn't apply to my situation.

First off, my car is a 2004 SVT Cobra, 60k miles, completely stock except for C&L intake, magnaflow tru-x pipe with MIL eliminators, and a Borla touring cat back.

Car has run perfectly with these few parts on it for a couple years now. Up until earlier this year when it started misfiring when going into boost. Out of boost is no problem and can run it up to redline smooth. But you punch it with boost and it just falls on its face with misfires.

Anyone ever heard of this and/or figured out the solution?

Many thanks

 

[oldmodman]

Put a mechanical fuel pressure gauge on the fuel rail. You could have a fuel pump dead or dying or a starting to fail Fuel Rail Pressure Sensor (frps)

Check to see if the fuel pressure drops when you hit the throttle. Running lean during boost due to low fuel pressure can be an engine killer.

 

[MaximusDecimus]

Put a mechanical fuel pressure gauge on the fuel rail. You could have a fuel pump dead or dying or a starting to fail Fuel Rail Pressure Sensor (frps)

Check to see if the fuel pressure drops when you hit the throttle. Running lean during boost due to low fuel pressure can be an engine killer.

I don't think the fuel pump has any issue seeing as it runs perfectly smooth pulling through the gears out of boost...
I guess I'll just blindly start throwing new parts at it starting with the FRPS.

 

[03cobra#694]

You would know if it was the FRPS. Start with simple stuff, plugs, fuel filter, air filter and cleaning the MAF.
Can you log it?

 

[Rich'sTRsvt]

I don't think the fuel pump has any issue seeing as it runs perfectly smooth pulling through the gears out of boost... I guess I'll just blindly start throwing new parts at it starting with the FRPS.

These cars have 2 pumps so they could run perfectly smooth out of boost on just one. As was mentioned data logging would help narrow things down.

 

[Riddick]

As stated above start with your plugs, im willing to bet thats the culprit.

 

[03cobra#694]

He mentions he can run it up to redline out of boost. At that point there's no real load. My guess is fuel filter, at that point the demand for fuel is there under boost.

 

[Roots-type]

As stated above start with your plugs, im willing to bet thats the culprit.

My first thought as well

 

[MaximusDecimus]

Thanks guys! Turned out to be spark plugs! Glad it was so simple Car is normal again!

 

[Riddick]

Glad you got it fixed. I'm betting the gap on your plugs became to big overtime and when in boost it was blowing the spark out. Depending how often you drove your car every year or 12k miles or so pull the plugs and make sure the gap is good.