Smoking Shed

[Martz]

My Audi 100 is a 4 cylinder 1.8 Carb. It is running pretty fast and continues to run after switching off (sort of chugs and stalls and trys to go again with the key out ). It also smokes a little. Could this be as easy as the carb needing a good clean or could it be something a little more?

Cheers

[topher]

  it means your engine is about to blow up !!





Kidding, its an ignition problem.. change points/rotor arm/dizzy cap see if that cures it. Has done for me many times in the past.

[Blue MK2]

could it mean the timing is out also?

[frankerooney]

If it's similar to an audi coupe 1.8 carb, then it's basically the 1.8 out of the golf GL. My brother had problems with run-on and traced it to the fuel cut off solenoid. Not sure if it was wiring or the actual solenoid. If you can find it, you could maybe test the voltages check out..
Running fast and smoke - perhaps it's running slightly rich?

[golfvr6]

If its idling high then it is likely to be the waxstat on the front of the carb, thats if its the same as a Golf GL.

[rubjonny]

Is this a Pierburg 2e2 carb? If so I had exactly the same over-run problem, I replaced both the electrical bits at the back (idle over-run valve and temperature time valve according to Haynes) Not sure which of these solved it but one of them did

Also If you find your engine starts and idles fine at 1k when you first switch on, but then later starts to rev at 1.5k, but then later idles fine at 1k again you might have a blockage in the piping that transfers coolant around the autochoke and waxstat.  Check the pipe coming out the back of the inlet manifold, this should get hot very quickly as coolant flows out the heat thru the manifold and out to the carb.

What happens is the O-Ring at the back of the head degrades and expands over time, and ends up totally blocking the hole so no coolant can get through.  On my 89 1.6 Driver, it resembled a lump of terd  

Failing that it could be the waxstat as golfvr6 says.

[Veedubgt18v]

What happens is the O-Ring at the back of the head degrades and expands over time, and ends up totally blocking the hole so no coolant can get through.  On my 89 1.6 Driver, it resembled a lump of terd  

Failing that it could be the waxstat as golfvr6 says.

yer my driver had that prob the other thing worth checking is the water rail could be blocked that runs from the top to the bottom of the engine. if this is blocked then it can lead to overrun problems. overunnig can also be caused by overheating which leads to hotspots in the engine igniting fuel vapour.

waxstat is easy to change, takes about 20mins do it when the engine is cold tho.

[rubjonny]

You'll loose coolant when swapping the Waxstat remember  If you just unscrew it from the carb when the engine is hot you can check if the pin is extended fully, if not its buggered!

Here's a nice piccy of the carb so you can see what we're talking about, the 'Expansion Element' is the waxstat!


And heres a piccy of the manifold O-Ring I was talking about, part 32.

[golfvr6]

oh no we got an expert on pierburg 2E2's  
nightmare carbs