I recall reading that the FCA has been known to cause rough idle problems. With my recent oil analysis showing no signs of abnormal fuel in the oil, I'm thinking that the injectors can be safely ruled out as the cause for my intermittent ruough idle. So what is wrong with the FCA when it goes bad? Can it be repaired at home, or do you have to buy a new one?

thx

 

My truck is at the dealer right now getting a new CP3 because the FCA was bad and the pump was leaking fuel. The FCA is that little black electric modual that plugs into the CP3. Its part of the the fly by wire system that tells the CP3 what to do. Mine would cut out and i would loose all power. I think a problem with the FCA usually throws a code and engine light, I got P0251. FCA is only ~$135 I think and all you have to do is remove the 4 torx bolts, unplug the old one, and replace.

Not sure that is your problem though. While FCA could cause idle problems i guess, just because there is no fuel in oil doesn't mean the injectors are fine. That just means they are not stuck open and leaking fuel down into the cylinders. They could still be mis-firing. I had #6 injector replaced due to rough idle and blue/white smoke and slight miss at low rpm's. No fuel in oil.

Scan tool can tell what % efficiency injectors are firing, or injector kill test.

 

The FCA is easy to change and only has 3 screws. My FCA was going bad and I found this out by the truck feeling like it was about to stall when I went to give it gas from a dead stop. The kicker was 3 months later when it was about gone my rail pressure jumping 3000-7000 psi when I was driving.

(My idle was never rough)

 

Quote:

Originally Posted by bradler

A scan tool can tell what % efficiency injectors are firing, or injector kill test.

Anyone know which scan tools feature an injector % efficiency test or injector kill test??? Are there any aftermarket scan tools that feature such a test?

Also, been following this thread and am wondering... "if" and "when" filter waxing takes place... does waxing permanantly effect & reduce fuel flow til the next filter change or does the wax simply desolve back into solution once temps return to the wax free/wax safe temp zone?