dspang

Hey guys, I'm having an issue with my 01.5 S4. For starters, it's chipped (not sure of the vendor, was in the car when I got it) and has an AWE exhaust on it. Approx. 2 weeks ago, I stopped for some fuel. Upon starting back up, the car almost immediately (before I was back on the highway) started misfiring whenever I moved the gas pedal. Since then, I'm still having the issue of misfires that cripple the car pretty badly whenever driving with any load on the engine. The only codes that have been popping up are misfire codes for cyl. 1 and 4. Assuming it was bad gas, I've added bottles of octane booster and dry gas treatments, neither one has done anything significant. One day last week the car worked fine for my drive home, then the next morning started misfiring again. I tried swapping coil packs around to see if the problem moves with the pack, but no luck, still misfires on 1 and 4. Swapped the ICM's and still, no change. I need to swap plugs around, as that's the last thing I can think of to try here. I've added about 7 gallons of fresh fuel over the past 2 weeks, trying to dilute the bad stuff with fresh.


Any idea's on what else it could be?

donromani

Was the fuel level very low when you stopped to refill? If so, it could be that you have a clogged fuel filter.

dspang

Yes, I had roughly 1/8 of a tank left when I stopped for fuel. I've got a new fuel filter sitting in the garage waiting to go on as well.

donromani

Hmm, 1/8th of a tank isn't quite running on fumes, so that makes the clogged filter less likely, but seeing as you've got one already it's worth a try.

RolledMySTi

New fuel filter and pressure test

dspang

Update: Swapped out the plugs for a new set. The existing plugs looked pretty nasty, so I was feeling like new ones would be the ticket. Took it out on the road, and it had the same misfires.

Got the old fuel filter out, put the new one in, turned the car to the on position to prime the fuel and check for leaks at the filter, and dammit there's a leak. On the line feeding the filter, right before heading into the fitting, there's a small leak when pressurized. I didn't see this before removal, so either I knicked it while taking the old one off, or it was existing just "clogged up" or something.

Looks like i'm taking tomorrow off and replacing a fuel line. Does anyone have any info on replacing this line? I'm guessing it goes up to the top and into the fuel pump?

Ugh.

donromani

Yeh, swapping plugs has never, in my experience anyway, resolved a misfire issue - that would just be too easy.

Sorry, I have not replaced that fuel line before, so I can't help you there.

complacentsee

It fixed mine before.

donromani

well good for you.

99 times out of 100 it is something unrelated though, and significantly more complicated.

complacentsee

I was just looking for a cookie