I'm fairly new to the list so i'm sorry if i'm being redundant. I have an 81 5spd wagon which I'm getting pretty fond of. Whenever it's cold it does not want to run very well, though it runs fairly normal when warmed up a bit. I recently changed the cold start valve, which does help a little, but it's still not right. I'm thinking it might be the MAF meter, because it seems to be running lean (getting good gas milage though) and it seems to run a little better when you reach in and move the meter flap open more. Would this most likely be the problem or would it likely be something else?? ...possibly timing. Does the comp. have the air/fuel ratio indicator's on this generation?

 

The air/fuel ratio is metered a bit by the O2 sensor.
I had this same problem, and most of it ended up being my ignition timing. Vacccume advance was screwed up to be exact. A dissasembly of the distributor, re-greased the three bearings, and reassmebled it to fix the problem. Try advancing the distributor itself manually to see if it clears up some of the low rpm stumbles. If it does, then its probably your vaccume advance.

Might also do a comperession test. How many miles on the engine? Maybe a new timing chain is in order... advance the new chain to help low/mid range power and get a smoother idle.

If you're running lean, it could be the AFM, but also air leaks in the rubber intake hose can cause a lean mixture. Remove and carefully inspect the tube between the AFM and the throttle body.

 

I ended up taking out the mass air flow sensor and finding some adjustment points. I decreased the flap spring tension which helped a little, but when I noticed the needle on the potentiometer was actually just past the range of movement when the flap was closed, I changed the needle angle accordingly and it helped greatly. I think it might not be a stock afm and I'm wondering if the stock one has these adjustments. The Haynes manual doesn't list anything about it, but I guess I'm not suprised. If anyone wants digital pics of what I did, let me know.

 

Yes, please send me those to: lang407@juno.com
Thanks

 

I would like them too, have been having the same problem. JayDubs@hvc.rr.com, thanks for the help!

 

The 2nd gens don't have that feature, the MAF is designed differently. It's just a hollow tube with a wire in it, you can't make adjustments to it.

-C-

 

Oh yes, the mechanical air meter, I remember those....they suck when they get gunk around the edges and become stuck...my 77 Mercedes 280E was like that.

S

 

Yeah, I should be able to send those pics tomorrow. Sorry 'bout the delay... been busy. I know there was another post of someone who wanted em, so i'm sending them to him as well. If anyone else wants them, let me know.