'95 A6 Throttle Problem?

[Pr0ph3t]

I posted about this issue on a couple of other Audi sites, but still have not found the solution. I have cleaned all of the electrical connectors on the tranny, cleaned the MAF, replaced the O2 sensors and the TPS, installed a new fuel filter, and cleaned the throttle body. Any other ideas; the CEL still shows a 2121 code?

"During our torrential rains last week, I got some water in the car thanks to a blocked drain under the cowl that covers the wiper motors and cabin air box. I removed the blockage and dried out the car but now I have a problem where my car just looses power periodically. I will be driving along just fine, then my CEL will come on and the RPMs will drop to idle. When I step on the gas, the car will sputter but it acts like it's not getting gas. It happens both when I am driving on the highway or trolling around town. Shutting-off and restarting the car (reboot!) makes the symptoms go away for about 3 to 5 miles.

The blink code shows a 2121 but that had been happening prior to the water issue. The car has 101k miles and has been well cared for.

Does this sound like a legitimate TPS issue to the Audi gurus out there or might there be some other explanation?"

 

[scotty33]

I don't know what model A6 you have, I'm sure it's not a 20v, but here's a link to 20v.org that may give you some insight?

http://www.20v.org/throttle.htm

The fault codes listing shows 2121 as an 'idle switch' problem, I know this could be part of the throttle pot on your car.

If the idle switch were stuck closed (or wiring shorted), i.e telling the ecu the throttle is closed. Then the car would idle ok, but fuel would be cut as revs climb above approx 1300rpm, I think!

 

[audi5e]

I had a similar issue on my 100 (C4/A6 shape). It became quite lethal on the freeway/motorway when the car would simply cut the rev back to idle. What was happening was the TP sensor was full of dirt that had accumulated moisture, this was telling the engine that the car was actually at idle position. What happens is the computer is still getting information from the speed sensors telling it the car is moving at speed, however the idle switch has been activated. The KEIII system is designed to cut the fuel using the pressure differential on the fuel distributor when the car is going down a steep hill and is using the engine to brake... hence when the TP sensor was giving an incorrect signal the fuel was being cut off until the road speed had dropped low enough to return the car to an idle state.

Not sure if your car uses the KE or KEIII systems? If it does then it sounds like you have a similar problem. In your case, I would check in the wiring to the TPS is still ok...