tippmann316

2000 Audi A4 Quattro, 1.8T has been at the local European Car Shop for two weeks and they cannot figure out it's ailment.

The car has been starting fine and running. But intermittently it will suddenly stall and not start again. You can crank it over as much as you want, but it won't even chug or sputter. Come back an hour later or a day later and it starts up. It may even start up 10 times. Turn it off and come back 10 minutes or ten hours later later and it won't start. No way to tell when and why it does this.
We have scanned it with an ODBII and no codes were reported.
The local shop tried the Fuel Pump relay and thought that would be it. But they ended up towing it back in a day later because the symptoms returned.
The local shop claims that the Fuel Pump is functioning (apparently even when it won't start).
I am thinking ignition module, MAF? But the local shop doesn't think so.
Any suggestions to look for?
Thanks.

@wesome

have you tried pulling your fuel pump fuse?

the other thing you can do is when it won't start; just keep cranking on it... sometimes it will eventually start. <--- That's from a bunch of ford trucks this summer but it still makes sense... that's usually the cam position sensor.

I remember reading on here though that it can be the coolant temp sensor... i forgot the exact reason why? Maybe ecu uses temp sensor with maf readings + 02 to slog in fuel? doesn't have the right temps then it throws in too much fuel, floods out the motor

all speculation

Fremder

mine has very similar simptoms and there's a cel whenever car doesn't start. vag-com shows the coolant temp sensor is going bad. So I'm going to replace the sensor sooner or later. Hopefully this helps.

Audi Junkie

Your shop seems unqualified.

audiTLC

check valves, ign module, etc- look at my sig line.

tippmann316

I was thinking ignition module. Never thought about the coolant temp sensor though. Wouldn't those items show up on the VAG COM?
And yes, my local shop seems unqualified. I know that now. But they have always treated my in laws well. So I want to give them a chance.

@wesome

just another wierd thing to check... solder on chip

tippmann316

Solder on chip... I will have to check that.

tippmann316

They claim that they are unable to find a reason for this intermittent problem.
I suggested earlier (and today again) that they check the ignition module, cam position sensor, and coolant sensor.
They have another Audi, same year and engine, and they claim it needs a main computer (ECU). So they are going to swap out my ecu with a new one just to see if this corrects anything.
I havn't even heard mention of an ECU on the forums. Could this really be the culprit? Wouldn't I be seeing other symptoms if this part were going bad? Everything else in the car works fine.

tippmann316

I have my reservations. So I am having it towed back home. I guess I will be handling this one on my own.
Everything else on the car works fine. It just has this intermittent starting and stopping problem. Does this really seem like an ECU?
I am curious though. I searched the forums and can't seem to get an answer. Where can I get an ECU if this is indeed the issue? I can't seem to find a good supplier.