90 Audi 90 Quattro with Check Engine problems!

[Aiken013]

Hello there. I'm new to this forum, but here it goes.

I have a 1990 Audi 90 Quattro. My problem is whenever I go over 3000 RPM, my check engine light starts to flash and doesn't stop until I go below 3000 RPM. Now, until recently there was never really a problem with how the car ran, but now it's starting to backfire and misfire a little bit.

Anyone know what is going on?

Also, my car is overheating when I sit still for a long period of time. I however think that it's my thermostat. Any thoughts?

Thanks in advance!

[domross]

If the thermostat is faulty it might well be worth replacing this as a first option...you may well find the other issue clears up once it is done...engine management systems can limit the revs on a car if they are picking up something is faulty so you don't damage the engine....as you would do running the car at high revs with the cooling system not working properly ,admittedly don't know if this is the case with the 90, but it has been the case on cars I have had b4. Cheers