Ok i been struggling with this prob for about 1 yr now, i got a 00 ws6 A4. The prob. is my car runs great when its cold but after warm up the car starts running like ****, while im drving normally the car will start to hesitate and misfire, at WOT the car will go off and after fire real bad. So far i chaged all coil packs(OEM),spark plug wires(MSD), spark plugs(OEM), clean MAF, removed EGR, gutted cats, cleaned air filter(K&N),changed fuel pump, changed fuel filter, changed knocksensors and changed crankshaft sen. but the prob. is still there. I am getting codes: knock sens. low input, and random multiple cyl. misfire .PLEASE any1 who can give me some input please help me out.

 

ok..what about wiring on your car? any wires cut...broken...worn through? obviously if you replace all that it should have fixed something.

what tune is in the car? has the car been scanned? I see you have a superchips programmer...what changes were made?

 

The car is returned to its stock application. I havent seen any visual damage as far as wires go.i been thinking it might be a wire or a bad sens but dont know which one or what will cause that. I took it to a shop they scanned the car and reflashed the computer and the prob is still there. Its just weird how when its cold it runs just fine, but once the car gets warm it starts running like ****. PLEASE help me out guys.

 

What do your plugs look like?, have you done a comp. check,no codes thrown.

 

havent done a comp check and i just replaced all eight plugs 2 weeks ago. the car runs fine at idle only under load is when it run like ****, and only at normal operating temp. while cold i can gun it and it will run just fine.

 

Try replacing your map or check for vacum leaks. Your mass air meater my be failing allso. oh and check the water temp sending unit on the head if that has the slightest fault it will make your car dump fuel. One other thing check our IAT make sure its clean. Oh and check your evap thing on the side of the intake and all your pcv equipment.

 

Ahh dam check your fuel pressure had a guy regulator go bad and he had 80 psi at the rails when he step on it. Do not ask me how that **** happen but I think it was a matter of his fuel tank some how built alot of pressure fuel cap would pop off some times. His car has all OEM.

 

have you broken off your coolant sensor over there on the drivers side near the header? just wonderin...

 

+ 1 on the IAT. Also did you happen to change the computer? I mean get another one and replace your stock computer. If you did, it will have to relearned by a dealer. Other than a sensor, if it's only doing it while hot, I would look at a compression check. Is it drinking any coolant or oil?

 

Ill check those things out OUTLAW, i already checked fuel press. its at 60psi at idle and drops slightly under wot(50-55psi then back to 60)Thanx. GOAT i havent changed the compu. its the same one it came with i havent noticed any coolent or much oil being consumed, ill try a compres. check that looks like a pain in the butt. Thanx for the input guys. if ne of you guys have ne other suggestions im open to almost ne thing right now.

 

It's your Fuel Injectors or fuel injector

 

I would handle that knock sensor issue first and then see where you stand.

A continuity check on the knock sensor harness would be a good thing to get out of the way.

I don't remember, is is possible for the knock sensor connector to be plugged into any other connector?


What does that mean? Tuning? Bolt-ons? Something else?

 

Ill check those things out. As far as stock appli. i mean stock tuning, got slp lid, k&n filter, 160 thermo, and the 2400 stall, but i appreciate all the replies and still open to ne other suggestions THANX every1

 

my car is doing something similar to this At WOT the fire stop[s and it dumps so much fuel that it backfires like a bomb going off and no one around here can figure it out

 

Goodwrench that sounds similar to my car it after fires and it soiunds like a shot gun giong off. I cant figure it out or ne1 ive spoken 2.

 

I thought I read somewhere that a stall would cause you to read a misfire code.....I think they said to max out all your misfire tables in your tune. 32767 I believe is the value to enter in each table. I thought you only done this when you had a cam......but im pretty sure I read that on this forum the other day.....whether that is true or not I have no idea but its worth checking out since you have already put so much effort into repair......good luck with it buddy. I would also try the new injectors as someone else stated above.