Inconsistent performance - 1985 BMW 318i

[Minnesota]

I have the 1984 version of your car. 111000 miles. I went through something similar last fall. The car is usually pretty snappy but it went through a phase where it was an absolute dog. I had just put a thread up on bimmerfest.com about this and the car snapped out of it. I drive it all winter long and it sits most of the summer.

I have no idea what the cause was or what happened that fixed it. I just drive it to work and back every day.

One thing to check is the connection at the computer, which is inside the glovebox. I have solved some poor performance issues by simply wiggling the plug on the computer, or tapping lightly on the computer housing.

[P B G]

Mine has up and died a few times in the past few months. When I head to down shift clutch goes in and engine just isnt' on anymore.

[trailsaw]

Originally Posted by P B G

Mine has up and died a few times in the past few months. When I head to down shift clutch goes in and engine just isnt' on anymore.

Check/clean idle valve?

[crazydrummerdude]

Originally Posted by crazydrummerdude

I haven't done the code checks yet

I was trying this today, as per the pelicanparts link, and... nothing. Hell, I don't even know where the check engine light is on this thing.

[trailsaw]

'85 318i does not have a check engine light....

[baldwithglasses]

It's the battery.

[crazydrummerdude]

Originally Posted by trailsaw

'85 318i does not have a check engine light....

Whether you're serious or joking, I believe it. But, so many people reference a CEL on 80's 318i's.

Originally Posted by baldwithglasses

It's the battery.

Probably.

[trailsaw]

Originally Posted by crazydrummerdude

Whether you're serious or joking, I believe it. But, so many people reference a CEL on 80's 318i's.



Probably.

serious

[crazydrummerdude]

Originally Posted by trailsaw

serious

Then, what light are they talking about? http://www.pelicanparts.com/bmw/tech...de_Reading.htm

[trailsaw]

Originally Posted by crazydrummerdude

Then, what light are they talking about? http://www.pelicanparts.com/bmw/tech...de_Reading.htm

\
Hell-even pelican can be wrong. All US spec SIX CYLINDER cars since '82 have had motronic. This is where the ignition timing interfaces with the injection profile and adjustments made on the fly.
'84 & '85 US 318's were still just "l-jet"-not motronic. A standard type distributor et al.
In addition-it wasn't until '87 that "we" got a check engine light by virtue of motronic 1.1 then available on the 325i/is/ic. In '88 all the other US cars followed-even the last year 528e.

[Minnesota]

Originally Posted by trailsaw

\
Hell-even pelican can be wrong. All US spec SIX CYLINDER cars since '82 have had motronic. This is where the ignition timing interfaces with the injection profile and adjustments made on the fly.
'84 & '85 US 318's were still just "l-jet"-not motronic. A standard type distributor et al.
In addition-it wasn't until '87 that "we" got a check engine light by virtue of motronic 1.1 then available on the 325i/is/ic. In '88 all the other US cars followed-even the last year 528e.

I hear you.

I read that article on Pelican Parts and thought, "Oh cool!" So I went out to my car and tried it...nothing. I have the jet-tronic, complete with the distributor and no check engine light. Someday I'll have to upgrade to the modern '87's and '88's.

[crazydrummerdude]

Ah ha! That makes sense, then.

Having so little money in the car, I might just take it to a shop and have them fix whatever's making it run rough. I figure that in order to keep the car free, compared to commuting to work in my truck this winter, I need to drive about 6 miles for every dollar I spend on it. Right now, I owe it about 2400 miles.

[crazydrummerdude]

Well, some new spark plugs, some more tuning/fiddling, and somehow-blowing (then replacing) my fuel pump fuse, it's running really nice now.



Knock on wood.

[crazydrummerdude]

This car has been my daily driver for quite a few months now. It runs fine. New tires and some other odds-and-ends, and it's actually almost like a regular car now!

The most annoying thing right now is an inconsistent smoke problem. Almost entirely randomly, the car will dump out a thick cloud of blue/grey sweet-smelling smoke. A possible constant is that this happens during deceleration from "at speed" driving. That is, I can drive around town fine and get on the highway, but when I get off the highway and idle down to the first stoplight, it dumps a cloud of smoke. Accelerating away, and it'll clear out and be just fine. Several stop lights later when I'm pulling into work and idling down the parking lot into a spot, it'll spew a thick cloud.

This happens not every time, but maybe every third time. The car doesn't run rough or any other indication of a problem, but every once in a while, it just dumps a cloud of smoke. It happens randomly whether the engine is at operating temperature or cold.. although it might be more often when hot.

Is my AFM getting stuck at the wrong setting? Is my 02 sensor on the fritz? Is my head gasket blown and sucking in coolant? Am I sucking brake fluid in the intake via the brake booster? Any ideas?

[willis 2000]

Originally Posted by crazydrummerdude

Is my AFM getting stuck at the wrong setting? Is my 02 sensor on the fritz? Is my head gasket blown and sucking in coolant? Am I sucking brake fluid in the intake via the brake booster? Any ideas?

The afm being stuck would give you other issues. Is your brake fluid level dropping? Is your coolant level dropping?
Maybe you'll need to re-engineer the crankcase vent. On a Lancia I had with L-Jet, I had to eliminate the PCV and run the crankcase vent with its own filter.