intermittent no start... driving me crazy

[G-MAC]

[Sorry this is a double post from the M20 sub-forum, but it might be solvable by someone who wouldn't look in that sub-forum?]

I have an intermittent “no start” condition that is driving me crazy. Any thoughts would be appreciated. This for a 1984 Euro 323i. Note that this is an early Euro E30, so there are a few unusual-ish things about it (no crank position sensor, for example, as it uses the transistorized ignition, and is controlled by L-Jetronic instead of Motronic; it is, however, an M20 engine, M20B23).

SYMPTOMS:
Most times the car starts no problem. Occasionally, maybe 1 in 15 times, I get no start on a warm engine (car has been sitting for about 30 to 60 minutes). I have not had the problem with a cold engine, but I’m not prepared to say it will “never” happen with a cold engine, since it’s so intermittent. Once the problem occurs, it happens more regularly for a day or so then starts behaving again. For the no start…
+ The starter turns the engine over nice and strong.
+ I have spark
+ I can smell fuel after a few start attempts
+ I can push start the car, and it starts every time (you know, push it fast enough and pop the clutch in 2nd gear… it starts every time).
+ It seems, though I’m not certain, that if I let the engine get completely cold it does start for me… I’ve “waited out” the issue a couple of times.
+ Once the car is started, it runs great… smooth idle, no issues while driving, nothing.

THINGS I’VE THOUGHT ABOUT:
+ Fuel filter? New-ish, so I haven’t replaced it again.
+ Fuel pump? Thought I’d have had drivability issues at other random times, instead of just a starting issue? And why would this be circumvented by a push start?
+ Fuel pump relay? Maybe, but why would this be circumvented with a push start?
+ Ignition switch? Circumvented that with a jumper wire right from the ignition coil to the battery, but still the same issues.
Both my mechanic and I are stumped so far…

OTHER “KNOWN” ENGINE ISSUES:
There are a few items on the “to do” list with the engine. I don’t think they’re relevant, but I’ll list them just in case…
+ Faulty oil level sensor.
+ Bad coolant temp reading; haven’t tracked it down to determine if it’s the SI Board, wiring, or sensor (I get a “less than blue” reading on the gauge at all times).

Anyway, I’ve got to solve this issue as it’s my daily driver and I use it to go to business meetings as well as just back and forth to work. My expert mechanics, who know older BMWs better than anyone I’ve every run across, have not been able to observe the problem (start every time I bring it to them!) so they’re stumped, too.

Any added advice? Thanks ahead of time.

[ethirdy]

My car does the same thing, but it's the starter solenoid. Just for shits, try hitting the starter/solenoid when it won't start warm while having someone turn the key. If it works....time for a new starter :)

[kamotors]

hard warm starts could be leaky fuel injectors, try fixing the coolant temp sensor, because i think that could make it run rich if its actually the sensor.

[smcdermott326]

here's a helpful website you may get somehting out of that you haven't already covered.

http://my.att.net/p/s/community.dll?ep=16&groupid=160912&ck

[bignate948]

i had the same problem and it turned out to be a bad wire that went to the relay

[Rocla]

On L-jetronic

i had the same problem and it turned out to be a bad wire that went to the relay

it can't be relay related, since:

+ I have spark
+ I can smell fuel after a few start attempts

Leaky injectors would be my quess too, try starting for about 30 sec on WOT.

[mtech2_touring]

Did you get this sorted, as I am having the same issues?

[jlevie]

Old thread from the dead, but...

In the OP's case my first suspicion would be one or a combination of; leaking injectors, leaking cold start valve, bad engine temp input to the DME. Later cars with Motronic FI don't have the cold start valve.