hi.

I have a b5, 1998 1.8 avant.

Lately my engine has been screwing with me. It's somehow not running correctly. I have to rev the rpm to get any speed, and the engine is making coughing-sounds. The weir thing is that the engine works fine for a minute or two after ignition, and the problem kicks in and out while driving. I had the engine overhauled 2 years ago at an authorized audi mechanic, and it hasn't gone more than 16000km since that.

I've had the problem earlier too. Back then i tried replacing the lambda censor, air mass meter, plugs and ignition wires, without luck. After a while with the old parts back on, it mysteriously solved itself. I can't afford a mechanic to take a look without having to live on noodles for the rest of the summer, so I hope anyone can help me here.

any idea what this can be?

 

Can you get it scanned for set or impending codes? That'll help for starters.

 

I would, if I could. I got a vag-cable, but for some reason, i cant get a connection with it. It reads the voltage, and sets the bautrate, but the ECU denies the connection. I would have to go to a garage/mechanic with proper VAG-equipment to get a read.

I actually did that last year, then there were no faults registered in the car.

BTW: I cleaned my car thorougly a few days before this happend. Including the engine room.

 

How did you clean the engine bay?

 

Ecu sounds bad

 

My thought is that if the OP washed the engine bay, God knows how many sensors are cooked. That's the last thing to EVER do to an Audi.

OP, try all different combinations of USB ports for the cable and port settings in Vagcom - on my laptop I specify port 4 but use the actual port 1 and it works fine.

 

I've tried everything with the VAG, and have concluded that my 14$ cable is not compatible or something like that.

I cleaned the enginebay with a wet spunge and a cloth. Rinsing it with running water afterwards.

 

Chances are, there's your problem. Smart money says you cannot do that to these engines. There are far too many sensors and contacts under there to risk it. The ECU is also underhood and can get damaged if water gets into its case (which would explain the Vagcom problem). Gotta think about this stuff before just hosing an engine down. It's not a carbureted small-block with one sensor and more wires on the headlight harnesses than in the engine harness.

Start tagging and unplugging harnesses, drying and cleaning them out, conditioning them with contact cleaner, and hoping you didn't ruin a bunch of expensive electronic components.

 

The VAG-COM works, just not with my set of equipment. I dont think it's the ECU. I checked the box, and there's absolutely no sign of water or any other damage to it. I'm currently doing what you are reccomending, and I hope it will pass after that.

 

It very well may be the cable you're using - some are less reliable than others. Hopefully working the wiring connections will fix the issue with the car but if water shorted the wrong pins together while powered up, you may have cooked sensors keeping the car from working right.