Update (resolved - 1st post) - E30 M42 sedan will not start easy cold or warm

[mr ilia]

Hi all!

Just week an a half a go I acquired a 1991 BMW 318i manual w/m42. This is my project car. Condition of the interior is 4.5/5, body is 4/5...mechanically is is not good, for the engine part at least.

Little history, not much here. For the last 1.5 years the car was not driven much, only in and out of the garage to get other cars parked.
Owner said the engine head was rebuild(? no idea to what extent), other than that he is not sure, he says the car used to run ok, but has developed few issues...

The engine is difficult to start cold or warm..the engine will crank but will have difficulties firing up...you have to keep cranking and stumping on gas and at some point it will fire up. When it goes life it will not keep idling, unless you keep your foot on the gas at above 1500 rpms or so...if you let it go, the engine will drop rpms to idle, but will die rather shortly.

Another issues....when running, if you press accelerator, the engine will not rev easy easy, it will sumble, resit and it kind of feels there is either no spark or fuel going to it..this will continue until about 2500 rpms..once past this point the engine will rev freely to about 4500-5000 and will no go any higher in rpms..it will kind of feels like it start to misfire and resist unless you keep pressing gas pedal gently, rpm will climb further. If I floor it, engine will start bogging and feels like it will die.
Engine may also backfire on seldom occasions and there is some little black residue coming out tail pipe.
Engine does not smoke or anything...

Stomp test results - 1215 if i run with original (rather dirty air filter..waiting for k&n in the mail) or 1222 if i run it with out air filter at all.
Without filter it runs worse than without.

Things I've tackled after getting the car:

- Changed plugs - #2 and 3 looked kind of dark and covered with black gunk, but 1 and 3 looked more less normal.
- heater plate delete and vacuum hose simplification (TB boot seems to have no cracks)
- little black plug near firewall is unpluged
- fuel filter changed
- fuel pump changed (I never heard pump "pumping")
- cleaned contacts on all 3 main relays
- pulled the head cover (see pics below)
- cleaned AFM with MAF cleaner
- disconnected OBC
- compression test 120-120-120-150 (1-4)

Things I find strange:

- I have L shaped ICV with --> arrow pointing towards intake hole (away from the TB) - I never heard it making any noises
- low, but consistent compression
- strange correlation of camshaft gears (see pics)
- I do not get any readings on the fuel pump plug (under the seat) with ignition on. My multimeter says 0.00 Volts.

I need help with the following:

- Is my timing off by a tooth? (low compression and backfiring)
- Should I change ICV to the T shaped one?
- should there be some voltage reading on the fuel pump plug with ignition on?

This is the position of the timing gears with 1st cilider at TDC (screw driver method)

http://www.flickr.com/photos/62581691@N05/5697118094/

http://www.flickr.com/photos/62581691@N05/5697117250/

http://www.flickr.com/photos/62581691@N05/5697116490/

May 14th - UPDATE - All resolved. Thank you!


I don't know why, but it seems that not every post i make gets "approved by the moderator".

After fiddling with the car without much success...i decided to order the whole bunch of parts that I think may need replacement as a part of maintenance. I got lucky and found more less local guy who has happened to have everything I may need.
I've ordered (all used, but working) - AFM, proper ICV, spark plug wires, FPR and original M42 coil pack, I paid for it 180.00 shipped.
The parts have arrived yesterday and I spend few hors getting them installed and while "there" I was cleaning up electrical connections and and some tiding up.
When I was installing coilpack, I noticed that original ground connections at the bolt pin have accumulated some rust particles. I've filed this away and gave it some wd40 treatment...forgot to mention, but few days prior I also filed and cleaned the ground connection junction that is on the left of the coilpack on the firewall....
I decided not to install FPR as it seems like it requires a fuel rail to be pulled....
All done and dandy, I jumped into the drives seat and started cranking....to my amazement....it is cranking, but not firing....I'm like WTF? What else could it be???
I tried jumping the fuel relay and I hear the fuel pump working, but no go...feels like there is no spark...I pulled one of the spark plugs and I see it super dry...like there is no fuel coming into the combustion chamber...what struck me was that before fuel filter and fuel pump replacement the could start..and now there is nothing, not even fuel coming.
I took off one of the connections at the new fuel filter, is passing the fuel, but to my surprise the line is totally dry...
I'm again, WTF??? Must be fuel issue, and very likely a fuel pump (I did Walbro install a week or so ago)....took out the fuel pump and was thinking about putting the old one back, due to possible defect in the new pump...in my understanding, things had to improve, but the opposite was happening. I went back started rechecking things I did. The most troublesome spot I thought would the fuel pump, as I already knew I had no fuel coming to the engine...I pulled a DIY from M42club, it was a great write up with pictures..and i started comparing what I have done vs what it says...one of the comments was about paying attention to the polarity of the terminals on the pump. It seems to me that was fine there...when I plugged in the connector, i was color matching to the pump frame connector, but I looked closely to the actual pump and here is what I found....This Walbro product had the black wire coming out of the positive terminal on the plug and the red one from the negative!!! The polarity was inverted!!!! The pump was pumping the fuel out of the fuel like and this explained the super dry plugs and fuel lines.
DUHH?? Wlabro how could you allow this to happen???

I put it back together again...cracked the motor and after few second of turning it came back to life!!!!!! And more, the engine was working beautifully; no idling issues, revvs freely to the redline, no more ill symptoms. I was finally paid back.

I has started working and i already put about 60km on it today and was able to pass provincial smog test....I feel very happy now.

In the conclusion, I'd like to reason things of what was actually wrong:

- Incorrect ICV was not functioning well with M42 - caused starting and idling issues
- Bad/rusty ground connection on the coilpack and engine to chassis - caused misfires and bogging/hesitation and generally rough running engine
- Worn out spark plugs wires - same as above
- May be malfunctioning AFM (I can't be 100% on this) - the same as above

[DesktopDave]

Welcome to the Club!  First post & a problem already?  I'm told that I can pass for an "M42 expert," so I'd suggest the following:

I had a 1215 when I got my car...the AFM had water in the connector/resistor pack that BMW fitted.  So I pulled it all out.  Seems that the motor wasn't getting a signal off the flap & wouldn't even start.  It seems a strong possibility that your symptoms are due to the AFM sending an incorrect signal to the DME, causing it to run rich at high revs.

I also had other problems:
The crank position sensor in these cars can be troublesome.  Clean it & be sure it's pretty close to the crank trigger wheel.  It's not adjustable, but verify that.  The car won't prime the pump if the computer doesn't sense crank rotation.

Difficulty starting can be due to:
DME losing crank signal
bad fuel pump
dead fuel pump check valve
defective FPR bleeding off fuel pressure.

Double check that you plugged all the holes & routed the hoses correctly from the hose delete mod.

I'd also clean & check that ICV.  It should buzz & vibrate softly when running.  I don't think you'll need to change it, they're all pretty much the same.  Doesn't seem to be a big part of your troubles right now though.

We've had debates about the fuel pump voltage while the car is off.  I suspect that the system primes when the key is first turned on, but then shuts down & waits for a signal from the crank sensor before it's powered up (as a safety system).  Also be sure you're testing the pump and not the fuel level sender.

[mr ilia]

Ok updates, nothing good for now.

Over weekend i put new fuel filter and fuel pump (walboro).
Cleaned ignition coil main harness pugs, removed and cleaned crank sensor (have not had a chance to check resistance of it). Adjusted spark plug gap to about 0.5mm (I use copper Champions)

Now - the engine would not start!! Not even single firing in the cylinders.Will try to boost it with my truck, see if the bimmers' battery a little low on juice.

I also ordered original used AFM, ICV and FPR along with a used coil pack (as myne looks kind of rusty).

I'll try to jump start it with shorted connection at the fuel pump relay. The pump does make noice when I do a direct connetion.

 - I'm thinking, after cleaning contacts, I might have connected the coil harness plugs incorrectly. How would I know which plug goes where? I could not see any matching colors or numbers.

[mr ilia]

I don't know why, but it seems that not all of my posts are "approved by the moderator".

After fiddling with the car without much success...i decided to order the whole bunch of parts that I think may need replacement as a part of maintenance. I got lucky and found more less local guy who has happened to have everything I may need.
I've ordered (all used, but working) - AFM, proper ICV, spark plug wires, FPR and original M42 coil pack, I paid for it 180.00 shipped.
The parts have arrived yesterday and I spend few hors getting them installed and while "there" I was cleaning up electrical connections and and some tiding up.
When I was installing coilpack, I noticed that original ground connections at the bolt pin have accumulated some rust particles. I've filed this away and gave it some wd40 treatment...forgot to mention, but few days prior I also filed and cleaned the ground connection junction that is on the left of the coilpack on the firewall....
I decided not to install FPR as it seems like it requires a fuel rail to be pulled....
All done and dandy, I jumped into the drives seat and started cranking....to my amazement....it is cranking, but not firing....I'm like WTF? What else could it be???
I tried jumping the fuel relay and I hear the fuel pump working, but no go...feels like there is no spark...I pulled one of the spark plugs and I see it super dry...like there is no fuel coming into the combustion chamber...what struck me was that before fuel filter and fuel pump replacement the could start..and now there is nothing, not even fuel coming.
I took off one of the connections at the new fuel filter, is passing the fuel, but to my surprise the line is totally dry...
I'm again, WTF??? Must be fuel issue, and very likely a fuel pump (I did Walbro install a week or so ago)....took out the fuel pump and was thinking about putting the old one back, due to possible defect in the new pump...in my understanding, things had to improve, but the opposite was happening. I went back started rechecking things I did. The most troublesome spot I thought would the fuel pump, as I already knew I had no fuel coming to the engine...I pulled a DIY from M42club, it was a great write up with pictures..and i started comparing what I have done vs what it says...one of the comments was about paying attention to the polarity of the terminals on the pump. It seems to me that was fine there...when I plugged in the connector, i was color matching to the pump frame connector, but I looked closely to the actual pump and here is what I found....This Walbro product had the black wire coming out of the positive terminal on the plug and the red one from the negative!!! The polarity was inverted!!!! The pump was pumping the fuel out of the fuel like and this explained the super dry plugs and fuel lines.
DUHH?? Wlabro how could you allow this to happen???

I put it back together again...cracked the motor and after few second of turning it came back to life!!!!!! And more, the engine was working beautifully; no idling issues, revvs freely to the redline, no more ill symptoms. I was finally paid back.

I has started woring and i already put about 60km on it today and was able to pass provincial smog test....I feel very happy now.