Apollopilot

Hello all! I'm a long time Audi fan and have just acquired this old classic 1984 4000s that I've decided to restore whilst keeping it a daily driver. The engine runs, but runs extremely rich and misfires. The car also can barely idle. Before purchasing the car the previous owner gave me some off the wall insight about adjusting a screw with a 3mm allen key located in the fuel distributor. I've found the screw, but have not yet made any adjustment as I don't really trust this guy's input. If it were that easy, why would he sell it, right?...

Anyways, I've looked through some of the other feeds and it sounds like the problem isn't new to any of you here and could very well be a vacuum issue as well. Any type of technical advice is greatly appreciated!

Thank you!

Austen

Rogviler

On these it's difficult to adjust the mixture without the proper equipment (an analog multimeter at least) and knowing what the reading should be. The old CIS basic could be more or less adjusted like a carb, but CIS-E is going to be more finicky. Regardless, that's not going to affect how it runs overall. So I would leave that alone for now.

I would 100% suspect a vacuum leak. Easiest way to find them is to blow or pump smoke into the vacuum system (engine off of course) and look for it coming out. It should only come out at the airbox. I usually use a $1 cigar from the gas station. Just don't inhale.

The propane or carb cleaner "trick" is largely useless as you'll never find the really buried leaks, such as the common one that develops on the underside of the air boot, in the folds.

-Rog

Apollopilot

Sir, you are a gentleman and a scholar. I’ve seen so many posts with your replies and technical advice and it seems like you’re quite the Audi guru! I greatly appreciate your advice and will do just that tonight as I stare at my machine pensively, asking myself what I’ve gotten into lol.

Rogviler

Thanks! The bad part about these cars is that a very small problem can really ruin your day (I've seen Chevys and Fords with completely trashed internals that still ran great), but the nice part about them is once you find that small problem it's almost always an easy fix and I've rarely seen anything catastrophic. Good luck!

-Rog

psparky

Apollo, are you in Washington state or Washington DC? I don't mean to discourage you on this project but finding parts can be very difficult. Shokan has a great supply of used parts but they are not cheap but then again they have them, just saying. You can desperate fast when looking for some items.

Apollopilot

Hi there! I’m in Washington state. Tacoma area.