I'm trying to fix a friend's car. It is an '89 740 n/a with the bosch injection system. The problem is that it sometimes stalls at a stoplight, and then it is really hard to get it started again, but once it starts then everything is fine. The problem happens maybe once every couple days. My friend first took the car to a shop and they replaced the injector and fuel pump relays but this didn't help. I have removed the battery cables (both ends), cleaned the terminals, and reinstalled. I have also checked all the ground wires under the hood to make sure they are tight and the connections are clean. The car also has a new crank position sensor as of a couple months ago. And it already has the replacement 951 ECU so I don't think that's the problem.

When I say it starts hard after stalling, I mean that it cranks and cranks before finally it will fire and run normally. It sputters some during this, almost like it is out of gas or something. Since it only seems to happen at busy intersections, I can't tell if the fuel pump is running or not during all this. The main fuel pump does not seem to make excessive noise or give any other indications that it is on its way out, although the car has 190K miles. I have not yet tested the in-tank pump to see if it is working or not, although that will be the next thing I check.

Any other ideas would be appreciated... Thanks!
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Matt L. -- Cary, NC -- '91 740 wagon

I had the same problem with my 740 turbo. It would run fine and all of a sudden sputter and die. It wouldn't restart right away and then would start and run like there was nothing wrong. It drove the previous owner so crazy he sold me the car as a parts car. It turned out to be a failing ignition amplifier (power pack) and a used one for $5.00 from the junkyard fixed the problem. It is located on the driver's side inner front fender in front of the strut and right behind and slightly higher than the battery. I have no idea how to test one other than swapping in a known good one and seeing what happens. Hope this helps.

I just had a 760T in the shop yesterday, that was almost a no-start. But it WOULD start, after a while, and it would run like utter crap.

At some point, someone threw a shitpot of new parts at this poor thing. They put in a new crank sensor, after breaking the bracket and having to take the trans out. they put in a new engine coolant temperature sensor as well. Of course, none of this worked.

Anyway, I replaced the in-tank pump. No good. Then the main. And that was the problem (dealer vehicle, so no charge for the in-tank pump to the customer).

Took forever to get started before replacing the main pump. That is a sign of a worn pump. It probably gets too hot and craps out. Then it is a pain to get running. But ultimately when it cools off it isn't too bad.

Sometimes you can tell a bad fuel pump by the exhaust smell. I can't describe it, but it is a very lean smelling exhaust. Unmistakeable, in fact.

If it was me... I'd center my investigation on fuel pressure, and the main pump.
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a Brickboard.com Expat
formerly known as Chris H

Thank you for the tip, I am also beginning to think one or both fuel pumps are having problems. I just wish I could repro this in my driveway but as I mentioned it only happens at the most inopportune times. I haven't been on the board at all in about 6 months (been busy with new job and other things) so when exactly were you expatriated?? LOL

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Matt L. -- Cary, NC -- '91 740 wagon

Congratulations on the new job, good luck with the fuel pumps if that's what it turns out to be.

Some anonymous loser on the OPINIONS forum, made a very deliberate project of intentionally posting untrue things about me and my character, so I figured, to hell with that, and I ditched. IT was nothing but a ruthless, personal attack, which is a really great reward for helping people out all the time. I've never seen the same person, give ANYONE help on this board.

The same oaf, just days ago, started a subthread that laid into people for supporting the board financially, calling the board a "Gold Mine" for the owner.

A gold mine. *snort* If you're mining for stuff like "working for nothing", "spending your own money so others can save theirs", and "blowing your spare time to host a free site", then indeed, this place must be a real gold mine for the highly esteemed site owner.

Anyway, so that's the rest of that story. That's the kind of rewards you get, for helping people out.

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a Brickboard.com Expat

I'm a relative newbie, bot old enough to recall your detailed yet succinct responses (I think?).

And thank you, thank you (did I say "thanks"?) for the white spaces.
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Bruce Young,
940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and going to be crushed unless...)
New 144 from '67 to '78
Used '62 122 from '63 to '67

See my post : http://www.brickboard.com/RWD/index.htm?id=680854

There are actually 2 radio noise suppressors, they are the 2 black plastic boxes (about 2"x4") hanging by a piece of metal. One for fuel and the other for the fan. They sit close to the strut tower on the passenger side. The one for fuel is the one closer to the fender and closer to the passenger side. When it goes bad it ususally acts when the engine is hot. So, I would let the car idle for a long period of time and reproduce the stalling then swap the 2 suppressors, and if the car starts fine then it's definitley a bad suppressor (the fan would stop working with the bad suppressor).

Yeah, I actually replaced the fuel pump relay before getting the suppressor replaced. The relay was still in good shape, and it seems the suppressor would go bad more often since it's under hood.

David