This is my first post so just hear me out and if I leave out any important information just let me know. We are talking about a 2001 Audi tt quattro I purchased a month ago. I got a really good price so I took it problem is the car has a few miles. It ran great but had a little noise (like a belt gone bad noise) I didn't care and kept on driving. Two months after at a light the car just died, it wouldn't start no matter what I did and was giving me a code (cam sensor). After hours of checking things we realized that tahe crankshaft gear was slipping on the timing belt. Guess they never replaced it and it was missing 4 or 5 consecutive ribs. I thought I had to replace the head and all that. I started by replacing the belt, water pump and serviced the belt tensioner. 90 dollars later and a couple of days worth of work I was back on the road. Didn't have a single problem till yesterday. I was driving and it felt like loosing power and it would go back to normal and loose it again. Almost like running on 3 pistons or running on fumes. I thought the spark plug was bad so I checked them and they are good, look like they are burning great (replaced when purchased the car: split fire) so the onlything left to blame is the coil or the injector. Now the worse part it is not a constant problem so is hard to locate. I switched the coil from piston four to three but the problem is still on four. The only codes are P0304, P1124 and P0128 or P1128 not sure about the last one. Can anyone help with this little bug? On top of that I don't even have the repair manual/CD is way too expensive. Still looking for a cheaper alternative

 

P0304 cylinder 4 misfire
P0124 throttle position ( TP )sensor A /accelerator pedal position (APP) sensor A - circuit intermittent
P1124 ?????
P1128 long term fuel trim, entire speed/load range, bank 1 - system too lean - problem is fuel pressure/pump, injector(s), intake/exhaust leak, air system, hose leak.

check wiring and connection to throttle position sensor/cam sensor/ air/vacuum leaks/exhaust leak, squirt some water on injector No4 to see if its drawing air through the seal also answered in tech section but I sorted the spelling mistake out here lol

 

The thing with checking the sensors on this car is that I onlly know where half of them are, I still need to get a repair manual even if it is a burned copy from a member. I thank you for the time and for providing me with possible solutions. I'll let you guys know what was it once I found it. By the way, the issue is not when steping on it anymore, it starts as soon as I start the car.

 

make sure you check the timing belt also it seems alot of people have problems with that up and around 50k - 60k mileage

 

Like I said in the first post the timming belt was replaced along with the water pump, idler roller and tensioner. I am running out of ideas and also trying to stay away from the dealer.

 

So far we are blaming a bad coil, # 4 and something that is giving the code P1240 any ideas as to what that could be or how to fix it?

 

P1240 is injector 4 - open circuit

 

check for break in wire to injector 4

 

Well, went to the dealer and bought all four injectors and stock plugs. Problem was cinder 4 plug and coil. Both were bad, the car started right up when I replaced them. I also replaced all coils and plugs and now.......no fuel, like the pump is not turning on or something. I am afraid I fucked the computer by turning the car on while connected to the code scanner. Is that possible??????????? I tried hooking the scanner back to the computer and is giving me an error....what's up with that.

 

check all fuses/relays connections to things you have installed, you can start the engine with the vag cable connected to run drive cycles so unlikely you damaged the computer more like a fuse/relay to the fuel pump