1986 325E.. starting problem driving me crazy - BMW Forum

system77 · 01-03-2009, 09:08 PM

Hi all.. So after a much ado Ive decided to ask if anyone can give me some advice on my issue.

1986 325E

Initial Problem: Was idling and conked out and now wont start.. tries to turn over, just wont start. Tank has gas, good battery, starter cranks like mad.

Initial Diagnosis:
Check for spark. Has good spark.
Checked voltage at fuel and main relay, has 12v
Checked all fuses good.
Checked voltage at pump.. no voltage..

So it would appear that if I had power at the relay but no power at the pump, the line is dead somewhere in between..
So I hotwired pump from relay with my own wires to the pump.. Pump makes its starting noise. Still No start.
Popped the fuel rail after the fuel filter.. getting fuel flow as long as the pump is hotwired.
As a double check I tried a replacement brain. No difference.
Spark Plugs were pretty bad looking, so I swapped them all out.

then it snowed and Xmas came.. took a few days off..

Got back at it, but NOW whenever I try and hotwire the pump from the relay, I blow the fuel pump fuse.. this is odd, as it worked fine before I gave up for a week.. Tried hotwire the pump direct from battery, pump motor still comes on. Ive blown 8 fuses today trying different things. (diff wires, cleaning leads etc... )

Just in case, I swapped out the fuel filter, as I read somewhere that a bad filter can cause stress at the pump and blow a fuse.. Still no difference..

What am I missing here? Tomorrow I plan to pop the Distributor Cap and clean it out and make sure all is dry, but this wouldnt explain my suddenly blowing fuel pump fuse every time I hotwire the relay..

Frustrating as just when it seems Im making progress, the new issue of the blowing fuse pops up

Could it be I need to reset the brain after changing the plugs?

witeshark · 01-03-2009, 09:26 PM

Maybe the pump has developed an electrical problem and that's causing the fuse to blow.

marti5 · 01-04-2009, 06:28 AM

You dont need to hot wire the pump!!!! the pump does not cut in until the engine is cranking!!, hense this is why you keep blowing the fuse.

You dont need to reset anything after changing the plugs.

system77 · 01-04-2009, 02:41 PM

Well I have read a number of conflicting tidbits of info on the pump on various forums I think including this forum.. Some say I should be able to hear without cranking, just turning the ignition to on. Others say what you've said.

Incidently, I dont hear it while the ignition is cranking, and when I popped the fuel rail, it wasnt pumping.. but when hotwired it pumps just fine.

And there are instructions for jumping the relay with a wire crossing the two proper pins but that has yet to yeild any results for me, Ive also tried various working relays.

system77 · 01-04-2009, 06:13 PM

Ok I figured out the fuse blowing issue.. must have been some moisture after the snowy weather, sprayed out around the relay plugs with some contact cleaner and no more fuses blown

So now.. I have fuel coming out after the filter when I crank

Car starts when I spray starter fluid into the air intake. Sputters out within seconds as the fluid is used up..

Pulled the first sparkplug at front of engine to make sure it hasnt fouled. Its still clean.

Wouldit be worth it for me to pop the distributor cap and check for corrosion/moisture? Not sure if this is neccesary considering the engine fires with the starting fluid..

Have also heard to check the cold start sensor..

or maybe my injectors are done or dirty.. ?

system77 · 01-16-2009, 03:10 PM

FUSIBLE LINK!

In the trunk coming off the positive terminal of the battery and hidden under the trunk liner and then wrapped in 3 layers of heat wrap there is a FUSIBLE LINK.

This was blown, so I bridged it and the car fired right up..

Hopefully this helps someone else that might search and find this thread!

This after I tested every other related companent in the car from ECU to CPS to COIL and back and then back again.

Got a good map of the car in my mind now though so Ill chalk it up to valuable knowledge gained!

Thanks all for your suggestions and advice.

witeshark · 01-16-2009, 03:17 PM

Happy to see you found an answer!

JERBER · 10-11-2012, 10:46 PM

I have a 1986 BMW 325 that has sat in the garage for the last 10 years. The engine will start, but then stall right away. I replaced the fuel and added a couple of additives (maybe too much for the amount of gas I added??). It still would not start, so I replaced the fuel filter. From the fuel line on top of the engine, AFTER the "T" split, the fuel flow is now about 1.3 litres/30 seconds. (I was told spec is 2 litres). All along, every once in a while it WILL start and run for anywhere from 2-15 minutes, and then it just dies. Any suggestions?

system77 · 10-12-2012, 07:04 PM

Quote:

Originally Posted by JERBER

I have a 1986 BMW 325 that has sat in the garage for the last 10 years. The engine will start, but then stall right away. I replaced the fuel and added a couple of additives (maybe too much for the amount of gas I added??). It still would not start, so I replaced the fuel filter. From the fuel line on top of the engine, AFTER the "T" split, the fuel flow is now about 1.3 litres/30 seconds. (I was told spec is 2 litres). All along, every once in a while it WILL start and run for anywhere from 2-15 minutes, and then it just dies. Any suggestions?

you bumped my old thread back from the dead just in time for Halloween!

I sold my 325 and bought an 88 535i.. hopefully by next month I own a 2003 330ci though. Then I can hang out here again

m20enginebuilder · 10-30-2012, 01:46 AM

Quote:

Originally Posted by system77

FUSIBLE LINK!

In the trunk coming off the positive terminal of the battery and hidden under the trunk liner and then wrapped in 3 layers of heat wrap there is a FUSIBLE LINK.

This was blown, so I bridged it and the car fired right up..

Hopefully this helps someone else that might search and find this thread!

This after I tested every other related companent in the car from ECU to CPS to COIL and back and then back again.

Got a good map of the car in my mind now though so Ill chalk it up to valuable knowledge gained!

Thanks all for your suggestions and advice.

I HATE fuseable links with a burning passion due to issues like yours. Thank GOD my one in my E30 is FINE. Dont change the fact that I hate them with a burning passion.

m20enginebuilder · 10-30-2012, 01:48 AM

Quote:

Originally Posted by JERBER

I have a 1986 BMW 325 that has sat in the garage for the last 10 years. The engine will start, but then stall right away. I replaced the fuel and added a couple of additives (maybe too much for the amount of gas I added??). It still would not start, so I replaced the fuel filter. From the fuel line on top of the engine, AFTER the "T" split, the fuel flow is now about 1.3 litres/30 seconds. (I was told spec is 2 litres). All along, every once in a while it WILL start and run for anywhere from 2-15 minutes, and then it just dies. Any suggestions?

This says fuel pump all over it. Try a new fuel pump.