M42club.com - Home of the BMW E30/E36 318i/iS
DISCUSSION => General Topics => Topic started by: Pedro on June 21, 2007, 08:06:12 PM
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My car saw a good share of its down time replacing/upgrading/fixing stuff. So she was all good and ready and ive been driving it for like a week now. Just filled up my second full tank since i started driving it. This morning i was headed to work and im cruising at like 80 when i feel it just start slowing like i let off the gas pedal. I'm in the fast lane so i put the hazards on, cross the double yellow then to the center divider. as im crossing through the carpool lane the car shut off.
It turns over and coughs like it wants to start but just never makes it there. i feel like its not getting fuel. So before i start getting into it i thought i'd see what you guys have to say. I hope its not the pump. the one in it has been in the car a while but doesnt not have many miles on it.
What do you think?
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Sounds like a fuel pump to me IMO.
Dan.
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The fuel pump has gone out before and thats what it feels like its doing. But with the fuel pump i had the luck of it being intermitent. You know everyonce once in a while it wouldnt start, but now its just wont start at all.
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It's fairly common for the wiring connectors/plug to the fuel pump to not make contact - intermittently. Spread the prongs on the pump a bit to create pressure between them and the plug. Could also be a fuel filter or the sock on the bottom of the fuel pump..
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i let it sit over night and i tried starting it and i got nothing, it just cranks over.
Does the fuel pump always run? I checked it with my DMM and im getting power to the pump but its not turning on. I know that sometimes i would hear it and sometimes i wouldnt.
Would the pump go bad from just sitting there?
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Not from sitting there, but it might be worn as it runs whenever the engine is on. Something could be loose as well. Sounds like you need a new pump.
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do a search ,there is plenty of info about fuel pumps and test .
To answer your question ,the fuel system has a return line so I assume that when the car is running the pump runs all the time together with the fuel pressure regulator.
When my pump went I put 12 volts directly to the pump and got nothing . that told me that the pump was no good. Don't go cheap , buy the correct one if you need it.They should last between 150 - 200,000 miles.
You could also hook up a fuel pressure guage at the pump and crank the motor to see what you have for pressure . You should have around 43.5 psi.
GOOD LUCK
(http://i141.photobucket.com/albums/r73/bogeyman700/fuelpump2.jpg)
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I dont have any power going to those two prongs in the pic above. I have power before the relay and none at the connector.
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Relay may be bad
you can try and jumper the relay. I believe it's the center one in this photo but I'm not sure . Hopefully someone will confirm this .When you turn the key to the on position you should hear or feel a click of the relay .
(http://i141.photobucket.com/albums/r73/bogeyman700/c4167b11.jpg)
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It's the white one.
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Relay may be bad
you can try and jumper the relay. I believe it's the center one in this photo but I'm not sure . Hopefully someone will confirm this .When you turn the key to the on position you should hear or feel a click of the relay .
(http://i141.photobucket.com/albums/r73/bogeyman700/c4167b11.jpg)
I ran wire straight from my battery to my pump and it turn on so i know the pump is working, i then used the same wires and touched them to the middle relay and clicked. i did it about 10 times to make sure it wasnt intermittent. I even tested out two others i took from a junkyard and they clicked also. i swapped them out and i had the same problem.
It's the white one.
according to this pic the relay is the middle one
(http://ee1394.com/bmw/docs/factory/repair/en/repair/images/0188.jpg)
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does anyone know where the wires for the connector to the pump go when they are above the tank but under the car?
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When you turn the key to the on position do you have 12 volts at the pump(under the rear seat) ?
When you jumped the relay did the pump run?
Are your spark plugs wet ?
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When you turn the key to the on position do you have 12 volts at the pump(under the rear seat) ?
When you jumped the relay did the pump run?
Are your spark plugs wet ?
No i didnt have 12 volts or any voltage for that matter. it was a big fat .0002v
Yes, but when i jump it, it sounds like the injectors are spraying too. I'm not really sure what that sound is.
I never checked the plugs but ill go check them now.
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So today i finally got 12v at the fuel pump, i removed the cover of the relay and watched it make contact while cranking so i know it was running the pump but its still not starting. It just cranks. I also had a crank sensor laying around so i swapped that and no luck. Anyone else have any ideas i can try.
Ive read through all the threads i could find through seaching and ive checked all wires, fuses and what not and still no dice. i have no idea whats up with the car.
ECU??
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If the camshaft position sensor is bad then the car won't start. I believe it controls the injectors and the crankshaft position sensor controls the spark.
I believe you should have around 1100 olhms at the camshaft sensor and 560 at the crank sensor.
It may be your ECU also but I doubt it . Do you have a known good one to switch out .
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If the camshaft position sensor is bad then the car won't start. I believe it controls the injectors and the crankshaft position sensor controls the spark.
I believe you should have around 1100 olhms at the camshaft sensor and 560 at the crank sensor.
It may be your ECU also but I doubt it . Do you have a known good one to switch out .
i didnt ohm out the cam sensor because i couldnt find one to compare it to.
The crank sensor was at 568 so pretty much right on what you say.
Ill just go ohm the cam and see if its around the 1100 you say or just OFL.
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I ohmed out my cam sensor and it was 1300 ohms but my connector wasnt showing any voltage.
Is there only 12v when cranking or when key is "on?"
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I checked my reference and the correct olhm is 1280 for camshaft so your within limits.
I don't know if there is supposed to be 12 volts on the other pin ??
Maybe someone else knows or can check it .
Have you confirmed that you are indeed getting fuel to the cylinders ???
AIR .......
FUEL ........
SPARK .......
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easiest way to test if you are getting fuel is disconnecting the fuel line at the engine itself, take a bottle and crank. If there's fuel comming out, you haven't got a problem there.
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easiest way to test if you are getting fuel is disconnecting the fuel line at the engine itself, take a bottle and crank. If there's fuel comming out, you haven't got a problem there.
+1
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easiest way to test if you are getting fuel is disconnecting the fuel line at the engine itself, take a bottle and crank. If there's fuel comming out, you haven't got a problem there.
Ive been super busy at work finishing up a protoype mustang.
Anyway.....
I disconnected my fuel line just before the fuel filter and cranked and nothing came out. I left the bottle on the line then ran wires from my battery to my fuel pump and it pumped fuel into the bottle. I then hooked it all back up and tried to start it and again it just cranks over and i get nothing.
My spark plugs do look a little oil fouled.