jump pack on the wrong way now car won't start

[cookster]

Hi all basically BMW e30 325i painter at work has put jump pack on the wrong way round and tried to start the car.now battery light is on and car will crank but won't start.checked all fuses and the inter link one there all good none blew which ain't good.car stinks by alternator so would imagine it's cooked that but would of thought it would still start joy if anyone can shed any light thanks Ben

[kam-325i]

could of took the ECU out.............

[cookster]

May well of done I have a spare 320i one is it worth swapping that one over I mean lucky it's not a brand new other wise would of been proper curtains I hate painters and this makes me hate them more

[Brianmoooore]

The only thing I would expect to fail is the diode pack in the alternator. Disconnect the thick lead on the alternator and insulate it with tape, then fit a charged battery and check that there is 12 volts on the ignition coil + terminal when the ignition is switched on.

[cookster]

Well that could be good news the battery is absolutely knackered so probably worth another one of those will jump on it Mon and check the voltage. Can't here the pump at all while cranking either which is weird thanks for your info bud

[cookster]

Is there any fuses under the dash or anything or is it just the ones under the bonnet thanks

[Brianmoooore]

The only fuse that affects the engine running is #11 in the fusebox, for the fuel pump.
On 325i saloons only, there is another 'fuse', a fusible link, near the rear mounted battery, in the smaller lead.
The only fuse on an E30 that is not in the fusebox is on the left hand side of the heater box, and affects the heater temperature.
The check on the + terminal of the coil is to determine the state of the fusible link.

[cookster]

The only fuse that affects the engine running is #11 in the fusebox, for the fuel pump.
On 325i saloons only, there is another 'fuse', a fusible link, near the rear mounted battery, in the smaller lead.
The only fuse on an E30 that is not in the fusebox is on the left hand side of the heater box, and affects the heater temperature.
The check on the + terminal of the coil is to determine the state of the fusible link.

No worries thanks for quick reply have checked all the fuses and cut open the fuseable link and that's good but I will do the check on the coil tomorrow and let ya no thanks

[cookster]

Well that could be good news the battery is absolutely knackered so probably worth another one of those will jump on it Mon and check the voltage. Can't here the pump at all while cranking either which is weird thanks for your info bud

Right bud fresh battery on cranks but no start and there is 12volts at the coil what next on the agenda to try can't here fuel pump at all so wondering if ecu is knackered have a 320 one is it worth swapping and trying It

[Brianmoooore]

Try the 320 ECU, if it fits the plug. A 325 should fire up and run on it, albeit badly.
Just let the ECU hang on the loom - no need to unbolt the old one or bolt the new one into place.

[cookster]

Try the 320 ECU, if it fits the plug. A 325 should fire up and run on it, albeit badly.
Just let the ECU hang on the loom - no need to unbolt the old one or bolt the new one into place.

Done that still the same so wouldn't of thought it be ecu now

[Brianmoooore]

I didn't really think the ECU would be faulty, but it was an easy check to make, to eliminate it.
Time to start treating this like a normal non starting car, and find out exactly why it doesn't run - fuel, spark, timing or compression.
Switch the ignition on and pull out the DME relay (usually white, under the cover by the air filter). Does it click as you pull it out, and click again when you push it back in?
Check for sparks at a spark plug and fuel pump activity when cranking the engine.
Any immobilisers on this car? The electronics on these, especially if aftermarket, are likely to be far less resilient than BMW bits.

[cookster]

I didn't really think the ECU would be faulty, but it was an easy check to make, to eliminate it.
Time to start treating this like a normal non starting car, and find out exactly why it doesn't run - fuel, spark, timing or compression.
Switch the ignition on and pull out the DME relay (usually white, under the cover by the air filter). Does it click as you pull it out, and click again when you push it back in?
Check for sparks at a spark plug and fuel pump activity when cranking the engine.
Any immobilisers on this car? The electronics on these, especially if aftermarket, are likely to be far less resilient than BMW bits.

Thanks for your help bud blew 2 relays the main white one for the dme and fuel pump changed them car now runs thanks for that

[Brianmoooore]

?? You can't 'blow' relays!