Engine stumbles/cuts out over bumps :(

[bloodsnot]

its the small wire next to the large cable to the battery on the right side

Thanks for the pic! One of the odd variations on the euro models is that the battery is actually under the hood up front, between the firewall and the passenger side shock mount. This is why I was confused when you mentioned the trunk. I'm sure it's got something like this in there somewhere there - I'll take a look. Thanks again for your input.

Check the relays on the driver fender, they pop out at times.

Also as stated the fusible link in trunk, follow it from the small cable coming off the positive lead. Mine was broken in a way that it would sometimes cut out.

Yeah I definitely need to check the relay. I say "relay" because yet another quirk of the [early] euro models is that there's a 7-pin relay that runs the fuel pump, the injectors, and the DME. Anyway, as previously mentioned, I did recently replace it so I'll double check that it's not wiggling at all. Thanks for the intel on how to find the fusible link, too!

[Holland]

My car has the same symptoms yours does for the most part. M10 on L-Jet. It sits now with a dead fuel pump. Check high pressure external pump, and your fuel relay.

[bloodsnot]

My car has the same symptoms yours does for the most part. M10 on L-Jet. It sits now with a dead fuel pump. Check high pressure external pump, and your fuel relay.

When you say "for the most part" - what were the differences? Do you just think that your pump was on its way out and eventually quit?

[bddog]

You need a new fuel pump.

[bloodsnot]

You need a new fuel pump.

How certain are you of this? Based on recent and prior research, I thought they were a "it ran fine when parked" type of thing that just fail to come on one day..?

Very interested in stories to the contrary, though, and definitely willing to look into it. I've tested my pump on the car and on a bench but not while knocking on it/shaking it...

I have two spare pumps I snagged at pick-n-pull before finding a fault in my relay during the last go-round of troubleshooting a few weeks back. Not certain either of them are in any better shape (they look pretty rough) than the one that's on there..

[Holland]

When you say "for the most part" - what were the differences? Do you just think that your pump was on its way out and eventually quit?

Basically my car would hiccup over rough pavement. Eventually it died one night going uphill under load. Did it multiple times trying to limp it home.

[bloodsnot]

Eventually it died one night going uphill under load.

I guess I'd better start carrying one or both of those spare fuel pumps with me in the trunk...

Thanks for taking the time to respond. I appreciate the info, however gloomy it may be.

[bddog]

Put a new one in unless you like being stranded on the side of the road. Any shop would have figured it out in a second and replaced it.Very obvious.

[Holland]

I guess I'd better start carrying one or both of those spare fuel pumps with me in the trunk...

Thanks for taking the time to respond. I appreciate the info, however gloomy it may be.

Just a heads up. Remember though, early cars have 2 fuel pumps. 1 in tank low pressure pump, and 1 inline high pressure pump. I already replaced the in tank pump, and now I'm 95 percent sure it's my external pump that's dead.

[bloodsnot]

Remember though, early cars have 2 fuel pumps. 1 in tank low pressure pump, and 1 inline high pressure pump.

Fortunately (or unfortunately), my car only has the external pump.

[Scallywagon]

Fortunately (or unfortunately), my car only has the external pump.

This will ultimately reduce the life of the pump, Did someone try to do a late model conversion in some strange manner?

I converted to late model single in-tank pump and deleted the external pump and bracket, took a clean install to get it stable but, what doesn't on these BMW's

[bloodsnot]

This will ultimately reduce the life of the pump, Did someone try to do a late model conversion in some strange manner

No, the '85 323i only came with one pump except for the Australian and Saudi Arabian models (at least according to RealOEM based on my VIN).

I replaced the sending unit a while back and the one that came out had no pre-supply pump and neither did the one that went in (based on the RealOEM P/N's).

[Scallywagon]

No, the '85 323i only came with one pump except for the Australian and Saudi Arabian models (at least according to RealOEM based on my VIN).

I replaced the sending unit a while back and the one that came out had no pre-supply pump and neither did the one that went in (based on the RealOEM P/N's).

I'm sorry I must have missed the Y/M/M

She's an oldy!

[Kozworth]

Sorry, I am honestly too lazy to read the post. What I would guess would be a likely thing to check out, is a shorting fuel pump. See if you can shell out a couple bucks for a cheap fuel pressure gauge. When your car cuts out, see what the fuel pressure is. My guess is there is an exposed fuel pump wire, and just through movement it might be shorting to ground then the pump stops.

[SubDad]

Another Euro-victim here, '86 M20B20, LE Jetronic and Telefunken ignition. OP, is your car the same? Does it have an actual distributor and a water heated idle valve, and have you realized that the Bentley manual doesn't cover our cars? If your car is anything like mine, that CPS up front has nothing to do with engine management, it's just for shop diagnostics.

I'd be looking for a loose connection or bad ground in the ECU circuits, the ignition system and lastly the fuel pump. .
When and if the car is running, start pushing wires around trying to make it stumble. I think the 323 had a socket just above the left mounting bracket, under the intake manifold, maybe start there.