So the other day, my X started to act much like it did when the stock fuel pump relay fuse went bad, but after checking it with a spare, that doesn't seem to be it. The car runs fine under light/moderate throttle, but it stumbles badly once it goes WOT, and it feels like the car is pulling timing like crazy.

At first I thought I might have gotten a bad tank of gas, but I've gently driven around for long enough to go through 2 more tanks of gas from different gas stations, and nothing seems to have improved. I don't have any logging software to see what's going on, nor the know-how to really diagnose/fix something like this myself, so I'm at a loss.

I would go back to the shop that did my tune back in '08 when I bought the car, but they are no longer in business. Does anyone know what might be causing this? Anyone know a good tuner that uses ECU flash in the Atlanta area that might be able to look at the car? Thanks in advance for any help!

 

Best thing to do is log the car. Also check afr. Do you have a wide band in car?

 

And it feels like its pulling timing like crazy cause it is. Get a buddy that has a Tactrix cable and check it out if u don't have one. If you have a fpr I'd check that first along with the wide band

 

Unfortunately not. I probably just need to find a good tuner in the area who can look at the car, but I figured I'd ask the community first to see if there is a common cause with an easy fix (like the fuel pump relay). Wishful thinking, I'm sure...

 

Is the car stumbling or bucking? If its bucking it could be a loose or torn intercooler coupler. Stumbling and it's not your relay, I would check your fuel pressure hose to the intake manifold by the oil dipstick.

 

Not sure (bucking, maybe). I've talked to a couple of shops that both said to check the spark plugs. From what they told me, since my car has 45k and still has the original plugs, some of them may have gone bad and the boost could be blowing out the spark causing misfires.

Seems plausible enough, I suppose, so I'm going to swap them out next week and see if that fixes it. If not, I'll probably just dump the car and take the loss on trade in, as I've been wanting to get rid of this thing for a while now anyway and don't need an expensive headache on my hands. Will report back once I find out more...

 

When I used to have an evo 9 I put on a bigger turbo got tuned and it started bucking, I bought a COP ignition kit for $650 and installed it with the same issue....I bought new plugs and gapped them correctly and the bucking stopped....go figure lol check those plugs!

 

Fingers crossed that it's that simple, lol. Will report back later once I find out. Thanks guys...