Broke down today

[capri_rob]

So took my E30 for its last outing until the warm weather and it broke down

Thankfully I managed to get it going again but it conked out just as I was coming up to a very busy crossroads, luckily the lights changed and I had enough momentum to get me most of the way across before I had to leap out and push it out of the way.

I'm guessing it's fuel related as the symptoms were very similar to running out of fuel - I.e no warning in the way of dash lights I only realised it was dead when pressing the throttle had no effect.

On trying to restart it would fire for a split second and then die again - did this 7 or 8 times. Then when it did fire it ran very lumpy for around 30 seconds and then the idel returned to normal and it was fine to drive home.

Whilst it was running rough I popped the bonnet but couldn't see anything amiss, no smell of fuel leaking, battery terminals tight, nothing arcing.

Is this likely to be a failing fuel pump ? Do they stick ? Fuel pump relay ? Crank sensor ?

On an 88 325i is there an in tank pump or is it external or both ?

Be grateful of some advice as to what I should check first and how to check it.

Car got me home ok and is now back in its garage I was nervous driving it back though.

[daimlerman]

Fuel pump is in tank,just a PIA to get at in a touring...

Rear seat bases out
Seat base securing rail out(several tiny grub screws with a small allen key)
Rear seat belt buckles out
Finally,carpet out,you may need to remove the rear door cill trims to get it all clear.

Then the thing lives under the o/s inspection plate.Note which terminal the feed goes to,as the bloody pump will run with the feed and ground(brown) reversed,but will fail to deliver fuel whilst squarking!

A pump that runs on the bench will not nesessarily deliver the goodies when in the car,replacement pumps can be fitted to existing carriers.

FPR is the one in the inner wing holder with a green/purple attached to it's holder,check by linking this terminal to the red/white power feed.This should make the pump run regardless of ign switch position.

Unlikely to be CPR,this usually gives a completely dead engine when it fails,starts with a misfire at higher engine speeds,though.

[Brianmoooore]

The clue as to what is wrong is what the tacho. did when the engine cut. If it was still reading what it should have when there was no throttle response, then fuel pump is a possibility. If the tacho. was reading zero, then its an engine electrical fault.
If it happens again, try to take note, while the fault is present.
In the meantime, take off the pump inspection panel under the rear seat, and carry something like a 2lb hammer with you, so that you can thump the top of the pump with the end of the handle if the need arises. (Pump is probably in the tank on an '88 model, but you'll know for sure if you remove the panel.)

[capri_rob]

Problem is now that the thing is actually running how do I diagnose it ?

Is what I've experienced today symptomatic of a failing pump ?

[capri_rob]

Taco was still reading when it died - I only realised I had a problem when pressing the pedal gave no response and the car was still slowing down hence me thinking its fuel related rather than ignition.

[daimlerman]

Taco was still reading when it died - I only realised I had a problem when pressing the pedal gave no response and the car was still slowing down hence me thinking its fuel related rather than ignition.

Fuel pump is prime suspect,they seem to enjoy pretending to fail and work perfectly when bench tested,belting the thing with a large Birmingham spanner as Brian suggested will often get you home,but a better,longer term solution is to replace the thing.

[capri_rob]

Cheers chaps. It's done 144k and I haven't replaced it in the time I've owned it so it probably hasn't done too badly

[Brianmoooore]

Quite likely that it is the pump in that case.
Definitely in the tank if we're talking about a touring. Non of the primitive stuff was used on these.
Getting at the pump is a bit more involved in a touring, when compared to a saloon, but not difficult. You need to unclip both seat squabs, then loosen the small grub screws in the fixing rail, so that it can be slid sideways and removed. Then there's the felt over the seat pan, which is a pain to remove, but cutting around three sides of a square with a craft knife gives a handy access flap.
Once the access panel is off, the seat fixing rail and seats can be refitted if they are needed.

[Brianmoooore]

Note that a stalled pump can blow fuse 11 if the correct 7.5A fuse is in place, so check that it hasn't blown if the pump won't restart when thumping it.

I once spent an entire two and a half week holiday in France with a pump in this condition, and we got the pump thumping routine - pull over, kids out, seat up, thump pump, restart, seat and kids back in, start off again, down to about 15 seconds. A time any F1 pit crew would have been proud of.

[capri_rob]

Thanks Brian. Haven't looked but as it restarted today I'm guessing the fuse will be intact

Just had a quick gander on ebay and new pumps don't seem to be too expensive thankfully.

[daimlerman]

You really should be looking at a Bosch pump....

[capri_rob]

You really should be looking at a Bosch pump....

£95 for a bosch one from GSF on their ebay page. Still not bad and got a few months to save up for it anyway as it won't be back out of the garage again now until the spring

[zd3bx]

You really should be looking at a Bosch pump....

£95 for a bosch one from GSF on their ebay page. Still not bad and got a few months to save up for it anyway as it won't be back out of the garage again now until the spring

I remember I bought a VDO one from eBay, complete with the housing for around £120.

But seems like that seller doesn't sell them with housings no more.

Might worth getting a quote from BM Mini Parts - often they have great prices compared to BMW and all the parts are all genuine.

[x98agw]

Hi. I have a 1988 325iX touring, and I ran into basically the exact same issue. The car would start sometimes, and would usually get me from point A to point B, but then would decide to not start. The odd time it actually cut out while driving, too.

I looked into a bunch of possibilities. I kept thinking that, since it would run from time to time, it wasn't the pump...but in the end, it was the pump. I actually got a used one from a guy who lived close by and it worked fine as long as I put a 10A fuse in #11. It would kill 7.5A fuses within minutes. The wiring can handle 15-25A if I remember correctly...so it worked for a temporary solution. I've even read that some US cars had 15A fuses in #11 as well, but I'm not sure how accurate that is.

Anyway, in the end I got a new Bosch pump and it's been great ever since. My guess would be that that's your problem. My car had around 170,000km on it the day it failed (which, coincidentally, was also the day I bought it)

Good luck. Let us know how it goes!

Owen

[Brianmoooore]

The pump wiring is most certainly not rated at 15-25A! The run current of an E30 fuel pump is around 2A, IIRC, but the reason it is fused at 7.5A is that the inrush current when the pump starts up is typically around three times the run current at 6A or so.
Early fuel injected E30s had two fuel pumps (a lift pump and a pressure pump), so the fuse rating was increased to 15A to cater for the inrush current of two motors starting at the same time. On later stuff (all tourings) the pump is a single one in the tank, and the fuse rating for these is 7.5A.
BMW considered it acceptable to fuse the pump with a higher rated fuse than was suitable for the gauge of wire used, because they were only providing short circuit protection, rather than overload protection as well, since if the fuel pump failed, the engine would stop a few seconds later, and the fuel pump relay would disconnect the power.
An E30 pump that pops 7.5A fuses is either a faulty pump, or not an E30 pump at all.

[x98agw]

Thanks for the feedback, Brianmoooore. I didn't say that the pump wiring, itself, was rated at 15-25A, the gauge of wire is what I was talking about. The used pump I got from another E30 owner was obviously faulty and drawing a bit more than 7.5A because of that, so I'm basically saying it was a fine alternative for a temporary fix while I waited for the new pump to come, to up the amperage on the fuse, and that the car's wiring can handle it.

Owen