540 starts, then dies

[onewhippedpuppy]

I have a rather odd problem with my '95 540/6. Sometimes when I start it, especially when cold, it will crank and start as usual, idle for maybe a second, then die. I start it again, and it runs great. It idles up like it's supposed to when cold, then slows down as it warms up. Overall it runs well. I recently did the upstream oxygen sensors, cleaned the TB and ICV. No codes or CEL. DME temp sensor maybe? Any ideas?

[tim]

My guess is a small airleak in the fuel line where the metal tube joins the rubber one, under the hood, over by the relays. New clamp or use heavy duty cable ties. I think you car is starting on what's left in the fuel rail. Then, because of a small leak (letting air in the line but not necessarily leaking), you have a bubble that stalls the car, then everything is fine once the pressure gets up again.

[onewhippedpuppy]

So are you talking left side near the fuse/ relay box? Does the 540 have a fuel pump check valve?

[tim]

No, but it can be retrofitted cheaply as many have done. You can put it alot of places, but I like after the filters, right after where the two join back to one. There's some extra hose there and some breathing room before it turns into the metal pipe.

[Bill R.]

was the problem you would have longer cranking times when hot. And if you have the leak at the fuel line that is mentioned below then you would smell gas.. My guess would be the icv or the contacts on the main or fuel pump relay.. i would start by cleaning all the connections and treating with stabilant 22



So are you talking left side near the fuse/ relay box? Does the 540 have a fuel pump check valve?

[onewhippedpuppy]

Never had a gas smell, and I just cleaned the ICV. I'll check the relay contacts.

[Bill R.]

on it as well... electrical connections on bmw's are very sensitive to small amounts of corrosion, not always visible. I get a fair amount of use out of my bottles of stabilant 22 on euro cars. Japanese cars never seem to have this problem.




Never had a gas smell, and I just cleaned the ICV. I'll check the relay contacts.

[632 Regal]

mine does the same type of rolling start, smooth then cuts back like the oil pressure bogs it down for a minute....obsure? Maybe this is a sympton of the oil drain back check valve? I havent noticed the oil pressure light staying on any more than usual though.

[onewhippedpuppy]

Oddly enough, this morning I turned the key to #2 and let it sit for 5 seconds or so, then started it. No problem! This might support the ICV contacts, if there's too much resistance and it's responding slowly. Where can I get stabilant 22, or are there suitable alternatives?

[Bill R.]

light bulbs etc basically every contact on the car with the exception of any of the connectors for the oxygen sensor. Bmw says no on the o2 sensor connectors. Then after cleaning them i treat them with stabilant 22 which is a connection enhancer and is recommended by bmw , vw, audi etc..
Stabilant is available from Volkswagen with a vw part number of
ZVW 186 001 STABILANT 22A or you can get it from a number of electronics shops if you check google or it has a napa part number of napa echlin CE-1, Borgwarner CL85 , Neihoff NL 5, partsplus CL85, Or from these guys who seem the most reasonably priced of the bunch.
(http://www.posthorn.com/Stab_2.html) I haven't bought from them so i can't say how they are, Gordon got me mine a couple of years ago..




Oddly enough, this morning I turned the key to #2 and let it sit for 5 seconds or so, then started it. No problem! This might support the ICV contacts, if there's too much resistance and it's responding slowly. Where can I get stabilant 22, or are there suitable alternatives?

[onewhippedpuppy]

Thanks, what about the deoexit d5, where can I find it?

[grease]

Oddly enough, this morning I turned the key to #2 and let it sit for 5 seconds or so, then started it. No problem! This might support the ICV contacts, if there's too much resistance and it's responding slowly. Where can I get stabilant 22, or are there suitable alternatives?
Hey have you checked fuel pressure. Maybe you lose fuel pressure and by leaving the key on position 2 it primes the lines, just a thought.

[Bill R.]

caig here if you want
(http://store.caig.com/s.nl;jsessionid=ac112b801f43e83286eb7a8f4faaa3e1b1 09113d9eb3.qQvJq2PEmlnva30N-BbQmkLz-ATzr6Lzn6rzqwTxpQOUc30KaNDNo6XKq6zInRmLa3mS8RbCpR0 HoA5Qmh0KaMTNo6XK-kDvrA4Ka3aIqRnvp6iIpAjOp6jynQjM-AbJpgaLax4LbNmLa38P8Oexo6XHngbynknvrkLOlQzNp65In0_ _?sc=2&category=188)




Thanks, what about the deoexit d5, where can I find it?

[Phatty5BMW]

I am almost positive this is not the problem but today I was talking to a guy about werid problems why cars wouldnt start and he had mentioned a plastic baggy in the fuel tank, pump sucks it up, car dies, restart, pump sucks it up, dies... lol sorry but thats just a little info, im not saying take apart your gas tank or nothin :P
GL on your problem man

[onewhippedpuppy]

Though I'm sure the stuff that Bill R recomends is better, I'm bad about planning ahead. This weekend I cleaned off the male ends of the ICV contacts with emery cloth, and after they were nice and shiny coated them with dialectic grease. Two cold starts, and no more problems. I cranked it immediately after turning the key and it still starts great. Thanks guys!