So I installed the new plugs and coilpacks and not surprisingly no luck. The car warms up and dies. no warning, no lights nothing just dies...then it wont turn over until cold again. I went through everything connection wise and everything seemed completely normal. I'm really unsure what to do at this point...Could it really be a bad ecu??? Has anyone had a bad ecu? I'm looking for anything here.

 

Do you have oil in the engine? Has the coolant? Battery terminals clean & on tight?

 

Check check and check...I just don't know...

 

...what about the engine speed sensor. I overlooked it but i have noticed that my tach has always been glitchy at startup..it almost hesitates and then is fine. and it is doing it now more than ever... I did read about someone else who had the same issue and that is what it was but i want to ask you guys.

 

As far as "warms up then dies", do you mean that when the secondary air intake shuts off, it dies? I know from a cold start, my car normally runs at ~1200 rpm for several minutes still slowing down to 800 as it comes off the secondary. Did your plugs look like you had been running rich or anything?

 

maybe its just the fuel filter.

 

I also replaced the fuel filter with no luck...I hear the fuel pump kick in when i turn the key and the pressure it is putting out is correct according to the fuel pressure guage i have in the car. As far as warming up I'm talking complete warm up. When the temp guage goes to about half way. I checked the temp sensor and audi already replaced that with the green top sensor and the fluid levels are all good. I've asked around and if was anything else the car would idle like crap or not run at all cold or hot. ie timing belt, hall sender, those types of things. The fact that the engine speed sensor sits right next to the oil filter and measures the rpms with the tach guage issues that i have been having it sounds right to me. By the time i get done ill have a new car i seems...

 

Oh and as far as the plugs they needed to be changed anyway...two were black and the other two were tan which is good but they have never been changed in 87000 miles so i did that alon with coilpacks since i didn't have the e version.

 

sounds like the speed sensor to me. mine went bad, car would run, but wouldnt start if you turned it off until it was cool. lets hope thats your problem, because if your pissed now, i cant imagine how you'll feel after doing all the work to replace a simple sensor, to find it didnt fix it. its a BITCH to get to it.

 

well my old A4 wouldnt restart when warmed/hot... it was a problem with the coolant sensor's there's more than one i guess in the 2000 A4, the system thinks its overheating and sends signal to ECU which to protect the car will not allow it to start/run till cool.

damn these thinking cars, huh? what happened to fuel spark and air with a cable runnin to the go peddle?