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e30 possible fuel pump issues

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Hey All,

Recently done an oil change and fuel filter change. Also changed Fuel pump relay and AFM within the last 6 months and all has been good until about last week. The car has been causing me starting troubles and will run like absolute crap when its cold, it takes about 30 seconds to start and almost catches then dies again. Once its going a puff of black smoke comes out and rpm sits at about 300 then fluctuates to about 500 and back down again. Whilst looking in the engine bay whilst this is happening i noticed the rubber fuel hose moves then the car rpm drops then picks back up again. Im not saying that its a fuel problem for sure it just seems a little ironic. Also when driving on a cold engine and putting the foot down it jolts and struggles to find power. This has been ongoing for about a week now and it really quite annoying.

Something i cannot work out however is the car runs flawlessly when the engine is at normal temp, there is no sludging, plenty of power and no jolting. This leads me to suspect that it is not a fuel problem.

Could someone please help me on this? Any other info you may need i can give you.

Cheers

Mitch

Edited by Mitch Wakefield

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also check your engine temp sensor , if broiken , not connected or faulty resistance readings.

if its not working it will over fuel your engine , causing black smoke etc

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Hey All,

Recently done an oil change and fuel filter change. Also changed Fuel pump relay and AFM within the last 6 months and all has been good until about last week. The car has been causing me starting troubles and will run like absolute crap when its cold, it takes about 30 seconds to start and almost catches then dies again. Once its going a puff of black smoke comes out and rpm sits at about 300 then fluctuates to about 500 and back down again. Whilst looking in the engine bay whilst this is happening i noticed the rubber fuel hose moves then the car rpm drops then picks back up again. Im not saying that its a fuel problem for sure it just seems a little ironic. Also when driving on a cold engine and putting the foot down it jolts and struggles to find power. This has been ongoing for about a week now and it really quite annoying.

Something i cannot work out however is the car runs flawlessly when the engine is at normal temp, there is no sludging, plenty of power and no jolting. This leads me to suspect that it is not a fuel problem.

Could someone please help me on this? Any other info you may need i can give you.

Cheers

Mitch

I can eliminate the fuel pump been an issue as all voltages etc have just been checked and all checking out good. Now looks to me as its the main relay as there is a click when i turn the key to on which i have never come across before. Any way of testing it?

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I can eliminate the fuel pump been an issue as all voltages etc have just been checked and all checking out good. Now looks to me as its the main relay as there is a click when i turn the key to on which i have never come across before. Any way of testing it?

Thats what a relay does when its functioning mitch. If your voltages have checked right then its getting power from the relay.

Check voltage across the fuel pump (disconnect it from the car). Not sure what a good resistance is, but you should be able to google acceptable values

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while the car is idling or starting tap the fuel pump with the back end of a screw driver or a rubber mullet.

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while the car is idling or starting tap the fuel pump with the back end of a screw driver or a rubber mullet.

Here it is here, this was done litterally 10m ago. Just cut out the swearing at the end. :P

Edited by Mitch Wakefield

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does it smell like gas at the exhaust when you were doing that? as i said try and tap the fuel pump while starting. happened to my e36 2 years ago. i started tapping it while having my bro start the car and it worked.

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does it smell like gas at the exhaust when you were doing that? as i said try and tap the fuel pump while starting. happened to my e36 2 years ago. i started tapping it while having my bro start the car and it worked.

It does smell like gas yes, ok i will get someone to start the car whilst tapping fuel pump. As in tap do you mean big hits or little repatative hits?

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little repetitive hits. but if it smells like gas its prob not the fuel pump. but try anyways

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little repetitive hits. but if it smells like gas its prob not the fuel pump. but try anyways

Just tried exactly as said and still nothing. Hmmmm its got a spark, all water temps etc are connected. I still have that clicking relay when i put the key to on however.

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as Andy said...relays are ment to click

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as Andy said...relays are ment to click

This clicking seems really weird though and its never done that before. It seems as though it clicks on then clicks another 2 times then does nothing. It only usually clicks once and now its doing it twice.

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spray some engine start or crc etc down the intake and see if it fires on that.

check if you have 12volts at the fuel pump when cranking.

you could put 12volts there and see if the pump runs and fuel coming out at the fuel rail etc

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sounds like you have a leak on the inlet manifold, which is small enough to temporary seal once the car is warmed up!

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sounds like you have a leak on the inlet manifold, which is small enough to temporary seal once the car is warmed up!

Well i have found the issue or what seems to be the issue at least. The 2 spark plugs that prooved good for a spark were numbers 5 and 6. Didnt test the other 4 which my father done and found there to be no spark. We tried the coil out of my dads bmw into mine and still no difference. Then removed cold air box and took dizzy cap off and saw that the rotor had chewn itself to pieces. Its nothing and all burnt up. Seems as though i might need a replacement rotor then, also would that expain my fuel efficiency problems ive been having?

Cheers

Mitchell

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