93 Coupe 2.0 16v ACE

[Lee73]

Hi guys, I've got a bit of a problem with my 80 coupe. It starts fine, no problem and pulls away fine but after a short while, say 3-4 minutes it starts to struggle, the engine loses power and its struggles to accelerate, however as soon as it reaches 2500-3000 revs it shoots forward with a burst of power.

It runs fine if I keep the revs near to 3000 and makes no difference if its hot or cold. If i'm on the motorway, doing 70 of course, it sometimes accelerates slightly then drops back down without me moving the pedal!

Even after a long run the problem is still there, some days its worse than others.

I'm not mechanical minded and don't know where to start. I have the 2 Haynes manuals from the cars before and after this one but this problem is not mentioned in the faults section.

please help if you can.

cheers

[scotty33]

Hi

I'm not sure what the problem is, sounds quite unusual. I think a fault code read would be a good idea.

it may be possible to do this yourself similar to this V6 method?

http://www.12v.org/maintenance/dtc.php?mil=no

failing that Vag com can work on the 16v so I'm told, IF the 'baud rate' is set to 4800 bits/sec.

The Haynes manual that covers the 16v ACE engine is for the 1992-1996 Audi 100/A6,
other than that the old 2.0 8v 3A engine uses a similar KE motronic injection system. The info that applies to that engine in the old Audi 80 manual will be closest to being useful to you.

[jaselp]

sound like a problem i had and it turned out to be the lambda sensor. you can get a fault code reader on ebay for £18

[scotty33]

I also came across the lambda sensor problem once, but it does not clear at 3000rpm, it clears at wide open throttle. this is because a corrupted/faulty lambda signal screws up the fuelling, but at wide open throttle the lambda sensor is not used by the ECU. As the engine is warming up, the lambda is also not used.
If the wiring to the sensor is damaged or spliced badly it could cause this.

if the lambda is the culprit, unplugging the wiring plug to the 'hydraulic actuator' should get you home. (this stops the ECU controlling fuelling, but the system will work quite well (like the older k jetronic mechanical injection) hydraulic actuator is located on the side of the fuel distributor

Lambda can be tested with a multimeter:


http://www.lambdasensor.com/main/mtesting.htm

[amy_turtle77]

Hi Lee

Did you find the cause of this problem, mine is doing the same and sometimes when it's hot it idles about 1200-1500 rpm. I had thought it was the idle control valve & a few friends have said the same. I was curious to know if you found what fixed it.

Thanks
Amy

[Peakster]

Hi Lee, I've got a 95 coupe. Mine to was doing that. I ended up re-newing fuel filter and cleaning injector manifold and lines. This worked for me. Hope you get it sorted.