Starting problems 325i sport

[ETERNITY]

I have always had a starting issue where it would start and I had to rev it to keep it alive but very occasionally it would not crank over and 2/3 times it would start.

The other day it stopped cranking over. The only thing I have noticed is a humming ICV, that sounds off. The starter motor sounds fine and it's turning over but it doesn't crank over.

Can anyone Help with the diagnosis.

[Speedtouch]

http://www.e30zone.net/e30zonewiki/inde ... oubleshoot

[E30M3EVO]

check fuel pump is being engaged when turning on the car. Located under the rear bench.

[Brianmoooore]

The starter motor sounds fine and it's turning over but it doesn't crank over.

So the starter pinion's not engaging?

[ETERNITY]

Yes it sounds that way, like no connection. Starter turns over and sounds like it's in working order

Appreciated

[Speedtouch]

Try hitting the starter motor with a club hammer, or rocking the car back and forth in second gear - this should free off the starter motor pinion if it's stuck.

[Brianmoooore]

This problem will have no obvious connection with your other problem of having to rev the engine to keep it running, so it looks like you may have two unrelated faults.
I'd be taking the starter motor out and inspecting it and the flywheel ring gear to see if there's anything obviously wrong.

[ETERNITY]

I will report back, appreciated.

[ETERNITY]

Fuel pump has gone

Which brand or where should I purchase one from

Thanks

[Speedtouch]

BMW often use Febi or Bosch parts as OEM. Try Eurocarparts, GSF, Carparts4less (CP4L), or even your local BMW dealer, who may even give you some money back in exchange of the old one...

[Brianmoooore]

What makes you think the fuel pump has failed? Not an obvious deduction from what you've posted earlier in this thread.

[ETERNITY]

My mechanic has diagnosed it.

[ETERNITY]

There was obvious reasons why it could have been the fuel pump because it has had some previous problems like it wouldn't start on the first attempt and splurting on acceleration just once then it would clear.

[Brianmoooore]

Fuel pump either runs or it doesn't, apart from a period of a couple of hundred miles when it first starts to fail, when it might give symptoms something like you describe above, but this rapidly gets worse, with the pump failing to start at all until thumped and suddenly stopping while you are driving along, requiring another thump to get it going again.
Your 'splurting on acceleration' would only happen a couple of times over a maximum of a few dozen miles before the car would start stalling.

[ETERNITY]

Ok thank you Brian that makes sense

Back to the drawing board and as you suggested Brian I will start with the starter motor and flywheel ring gear

Thanks

[Brianmoooore]

One thing I am absolutely sure off, is that the failure of the starter motor to engage is definitely nothing to do with the fuel pump!

[ETERNITY]

The mechanic tested the fuel pump and he said that's the cause because it wasn't priming or making any sound while trying to start so I am not sure. Regardless I think replacing the pump maybe a good a idea

[Brianmoooore]

1/ E30 fuel pump doesn't prime, unlike most modern cars. It only runs when the engine starts turning.
2/ Not making any sound when you crank (try to start) the engine may be either because the pump is dead, OR because the pump isn't receiving electrical power. The plug should be disconnected from the fuel pump and a 12 volt bulb connected to the plug, and then the engine should be cranked. If the bulb lights at full brightness, and the pump still doesn't run when the plug is reconnected to it, then the pump can be condemned.

[ETERNITY]

Ok thank you for that Brian. Will report Back

[BenHar]

I think there is a bit of a problem with the description here.

OP says it turns over but does not crank.

Do you mean that the engine turns but does not start or that the starter motor turns but the engine doesn't?

Ben

[Brianmoooore]

I think there is a bit of a problem with the description here.

OP says it turns over but does not crank.

Do you mean that the engine turns but does not start or that the starter motor turns but the engine doesn't?

Ben

I specifically asked about that in the fourth post on this page, and fifth post confirms starter turns but not engine.

[BenHar]

I think there is a bit of a problem with the description here.

OP says it turns over but does not crank.

Do you mean that the engine turns but does not start or that the starter motor turns but the engine doesn't?

Ben

I specifically asked about that in the fourth post on this page, and fifth post confirms starter turns but not engine.

If that is correct then, like you, I don't understand how the fuel pump can cause it!

Ben

[ETERNITY]

The starter motor turns but the engine doesn't engage.

[BenHar]

The starter motor turns but the engine doesn't engage.

So the engine doesn't turn?

If that is the case then the fuel pump is not the problem.

Ben

[ETERNITY]

No engine doesn't turn but the mechanic was convinced it's the fuel pump because starter motor is fine. Gong to follow Brianmoores advice.

[Brianmoooore]

If your mechanic truly believes that the engine is not turning over because of a duff fuel pump, then you need a new mechanic ASAP!
I'd love to hear how he makes the connection.
Are you sure you're reporting this right? No one who knows anything about cars and how they work, let alone someone who claims to be a mechanic, could possibly link a non engaging starter to a duff fuel pump in a thirty year old car. Modern stuff, with their interlinked can bus systems, are a bit different. ll sorts of weird interlinked problems can happen with these, like the Merc. I got involved with a while back, where failure to respond to the throttle turned out to be caused by the brake light section of a defective rear light cluster.

[E30M3EVO]

If the mechanic is 100% sure, then ask him to purchase the fuel pump and replace it. If it fixes the problem, then pay for the part. If it doesn't, then it's his loss and needs to investigate further.

Or get a 2nd opinion from another local mechanic.

I can vouch for Brian's advice and has always been right from my experience.

Hope that helps