What do you think is up with this?

[E30SPDFRK]

My m30 skips pretty bad. When I went through the engine, I changed:

cap
rotor
timing chain/tensioners
plugs
every gasket
valve guides
had the head checked
fuel filter
tps
afm
and other things that I am forgetting

I know the timing is correct; I swapped the wires with another set I had- no change; plugs are all gapped to .030.

Video of it running

http://s182.photobucket.com/albums/x96/e30spdfrk/?action=view&current=DSCI1021.flv

It kind of pops out the exhaust when you let it sit idling for a while, so I'm thinking the injectors are leaking. I cleaned them with carb cleaner when I had them out, but I never tested them or anything. Think this could be the problem?

[euroshark]

A can of BG44K is the easy way to figure out if your injectors are dirty. Make sure your O2 sensor is working properly.

[E30SPDFRK]

O2 sensor isn't hooked up, I didn't think it needed to be. Does it really need to be?

[SpecM]

O2 sensor isn't hooked up, I didn't think it needed to be. Does it really need to be?

o2 sensor shouldn't cause an m30 to miss

[E30SPDFRK]

Thats what I thought.

[euroshark]

I disagree, the O2 sensor is an integral part of the Motronic system and it does not run correctly without it. If you are going to troubleshoot effectively you need to check everything, including the O2 sensor.

[E30SPDFRK]

I wish it wasn't so cold out, I wanna go try hooking it up and seeing if it works. Do you really think that could be the problem?

[euroshark]

Not necessarily, I'm just making the point that BMW and Bosch design things the way they do for a reason, so running it without the O2 sensor at the same time you are trying to diagnose an engine management issue is counterproductive! I think you need to go down the list of possible culprits and eliminate them one by one. If you have the Bosch Fuel Injection and Engine Management book it will help.

After watching the video it really sounds like you have an inactive cylinder or two. Check to make 100% certain that your spark plugs are properly seated in the head and torqued to around 14ft/lbs, make sure the plug wires are fully seated on the plugs and at the cap, and make sure they are going to the proper plug.

If all of that is correct, the only other thing that would cause an inactive cylinder is a lack of fuel. Take the longest screw driver you have, put the tip of it to an injector and the handle up to / in your ear. With the car running you will hear a rapid and fairly loud ticking from each injector, it's unmistakable. Check all of them and listen for one that isn't doing anything, or possibly ticking very quietly or not as quickly as the rest.

If you do everything above and it is still running like that, I'd check a few more things. Make sure the ECU and AFM you are using are correct for each other. Did you get them from the same donor vehicle? Make sure the TPS is adjusted properly. If you need instructions I'll be happy to help. I'll brainstorm and see if I can think of anything else...

[E30SPDFRK]

I checked the ignition system a few times, I'll do the screwdriver trick tomorrow. I don't think an injector wouldn't be working though because it makes a popping noise out the exhaust like it is running too rich. Maybe a leaky injector?

Electronics are from a bunch of different cars, but they are all from either e34s or e32s.

Where are you supposed to set the tps to? I left it loose while the car was running and set it just before the click that makes it run rough.

[euroshark]

Could be a really leaky injector... it probably won't click, or it will be very muted because it's gummed up.

The TPS thing has me intrigued though. You say it was loose when the car was running well, and when you set it wherever you set it, it started running rough?

The TPS should be adjusted to that when the throttle is closed you are activating the idle portion of the switch. The smallest opening of the throttle should bring it off of that switch - that's the click you should hear. And when I say small opening, I'm talking like 0.5mm, literally the closer you can get it the better. Same goes for the full throttle end of the switch, only full throttle should cause it to click onto the full throttle switch.

Unplug the TPS all together and see if anything changes.

[Doughnut]

I'm temporarily running my e30 m30 without a o2 sensor and it runs fine. Although it is not recommended because it will ruin the catalyic converter with the extra fuel being put into the exhaust system.

Sounds like something a little more serious than a faulty injector or spark plug/lead.

[E30SPDFRK]

I don't really know how to explain it, but I'll try my best. At the end of the travel of the tps, there is a little click. If I adjust the tps when the car is running and hit that click, it runs worse than it already is. I set it to right before that click. Nothing changes if I unplug it.

I checked the injectors with a screwdriver today, and a few weren't ticking. #1 definitely wasn't and 5 and 6 didn't sound like they were but they might have been- My screwdriver wasn't long enough to reach them without hitting the afm. The open pipes make it kind of hard to hear also.

My engine skipped when I first bought it, but i figured that was because of the leaky valve I found when going through it. The harness came out of a well running car, so I am pretty much positive that it is my injectors now.

[euroshark]

Yeah, I'd start with either BG44K or swapping in some known good ones. It definitely sounds like you are having injector issues.

[E30SPDFRK]

I didn't feel like starting a new thread, so what wires need to be hooked up to the alternator? All I have is the one that comes from the starter. I was running some injector cleaner through today when the engine slowly stalled out. I went to start it again and the battery was dead, so something's obviously missing.

[euroshark]

Ahh! The plot thickens. There should be two wires going to the alternator I believe... Lemme go snap a picture of my 6 series, it might help.