Tech Forum : starter, fuel pump, alternator or all 3?

g323

Posted Friday, Nov 30th 2:17am [Edit] [Quote] [IMS] [View car]

Member
Post nr. 201

California
323i 1982

I have a number of problems right now. THe battery keeps draining and i keep having to take it to get charged. The car sounds like the starter is goin out, and the other day i started it up, it caught, and then died. i could only start it by leaving it in reverse and turning the engine over.

I can change the starter soon, but the battery draining is stressful, and i worry about the third problem which i am guessing is fuel related but am also guesing im wrong.

any ides,
thanks!

Posted Friday, Nov 30th 11:22am [Edit] [Quote] [IMS] [View car]

Member
Post nr. 48

NY, USA
82 528e2i 84 320i/4 80 320i

I would start by checking the cables and ground straps. If there is a bit of corrosion anywhere in those, reducing the current carrying capacity, it can very well cause starting/charging problems.

Also, buy a charger

melloh

Posted Sunday, Dec 2nd 7:54am [Edit] [Quote] [IMS] [View car]

Member
Post nr. 615

California, USA (San Jose)
1980 320is, 1991 318is

This is also for my own education (so more a question than a solution, sorry), but if your battery is draining (over night?), then while the car is off, is it possible to use a multimeter to check if current is passing through any of the fuses? For now, you could detach the battery while you park over night.

Or, are you saying the battery drains while the car is running only?

As for the starter... from the reading I've done, the solenoid is often the culprit. The 'cult' test is to tap it (how hard?) and see if it improves. I've never had to do this, though. If it is, the soleniod is cheaper to replace than the entire starter.

BarryA

Posted Monday, Dec 17th 8:24pm [Edit] [Quote] [IMS] [View car]

Member
Post nr. 207

Sacramento CA
81 320

melloh wrote:

Got a similar problem with my wife's 633 CSi right now - I can bring the battery up to full charge using a battery charger, and even though the car is driven daily, the battery will slowly lose enough charge that the car will fail to start after a several days (battery's almost new, and been load-tested - it's fine).

Although I suspect insufficent alternator output to be part of the problem, the primary issue appears to be a "parasitic drain" on the battery - somewhere in the system, something that's supposed to be disconnected when the ignition is "off" is still getting power (the problem started after doing some work on the stero system - the amp's the main suspect).

Diagonsing the problem will require disconnecting the positive battery cable, connecting an ammeter in series between the battery positive post and the cable, then disconnecting circuits until the current flow through the ammeter drops back to near zero (in any car with a clock, digital tuning stereo, or fuel injection there will be a constant, slight draw from the "memory" circuits, but it should be no more than 1-2 amps when the key and all lighting is off).

Start by pulling fuses one at a time while watching the ammeter - if the meter drops back to near zero when a fuse is pulled, that circuit is probably your culprit. If none of the fused circuits is a problem and there are additional circuits connected between the battery positive post and the fuse box, disconnect each one one at a time and see if the amp draw drops.