'87 325i Runs/Idles Rough, cluster lighting, rear defrost doesn't

[Chris W]

Problem 1. started with wife driving to work on highway. She says it just started running rough with a vibration while driving normally. It starts and runs rough. The idle seems to kick up(@ 1000) and then back down to normal idle shortly after I start it up.
I pulled plug wires, with it idling, and the 1st cyl, closest to the fan, didn't change how it was running. Checked for spark, YEOW! yes it's getting juice. Pulled plug which appeared to be wet with gas. hmmm if it's getting fuel and spark why ain't it combusting????

Prob 2. I think this may be a ground wire issue. Half of the instrument cluster(left half) lights up when I turn on the lights, the right half won't. Along with the dark rt half the OBC doesn't light either unless the lights are turned off like during daytime driving. I've been driving this car 4 about 4 months now and on one single occasion the dash lights all were lit and the OBC as well so I know all bulbs are fine but the OBC lighting and half of the instrument cluster are tied together somehow....any clues for me?

Prob 3. The rear defrost has 12v across the leads at the rear window but the defroster does nothing on those frosted mornings. Is there a fuse somwhere in the rear or is there no hope for the rear window dfrost???

[FatKidRacing01]

Problem one check you iac motor (if equipped) also if your getting fuel and fire then i would guess timing? How many miles?
Problem two bulbs burnt out... which cluster do you have? I have some extra clusters with good bulbs ill mail them to you pm me your adress
Problem three Take one of the leads off and ohm out the strips usual cause is someone removing window tint and knicking/cutting the gold strips if it is only one strip you can repair it if not....order a new rear glass i get them for about 150+80gasket+40 for install

[Chris W]

What is the iac motor? The engine has about 215k on it. I believe the timing belt is relatively new. I did have the cluster out and shuffled a few bulbs around and that had no effect on the lighting. I did experience a time when everything was lit so I feel the bulbs are not the issue.

[Chris W]

Zero Compression on Cyl 1!!! I think this may be my problem(sarcastic). I have apparently lost a valve but the beast still runs! Any reccommendations on an '87 with 210K miles. Should I pursue repairing this problem or just scrap it and walk away? IF I rebuild the head should I expect to lose rings or something else next???? IF I were to part it out what items would be easiest to sell and pull from the car before I let a wrecker take it away, with a tear in my eye!

[witeshark]

The bottom of the M20 engine tends to be quite strong.