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Im here just about to get this thing started and its giving me a bit of trouble. I have an e30 M3 s52 obd1 turbo build and tomorrow it is going to get outfitted for exhaust and charge piping. I wanted to get it started to get it out of my driveway and into the fabricators garage but it is not getting fuel. Cranks fine, its just that the fuel pump is not getting any power. When you turn the key there is no priming of the pump. I checked the voltage on the fuel pump relay pins and all are normal except the violet/green wire is not reading anything. I jumped that pin (87) to pin 30 and the pump runs. I switched out the relay for another, no dice. There seems to be some problem with the ignition and the fuel pump communicating. Thoughts?
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Fuel lines reversed?
Member
Wouldn't the pump still turn on? It does when I jump it from the relay.
Member
Check power connections. DME is not getting power, from what it sounds like. On the connector bundle that the diagnostic connector is connected to, there are two wires on an OBD-I E36 M50 wiring harness. One is power, one is ground.
Do you hear a momentary pulse at the fuel pump in the KEY ON position? You should. If not, the DME definitely is not getting power.
Fuel lines reversed does not cause the fuel pump to not turn on.
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Just checked the two wires you are speaking of fred, they are a-ok and receiving voltage. I even peeled back the black insulation to make sure that I am color coordinating (brown for ground, red for power) the connections properly and not switching them up.
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Is the cel wired up? Does it come on?
senior LOUNGE creator
Seems like the car is telling you to sell it to GG///M3
“If liberty means anything at all, it means the right to tell people what they do not want to hear.”
― George Orwell
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What DME are you running? EWS disabled?
Member
The CEL does not need to light or be wired for the car to start, and pulling codes won't tell you much of anything if the fuel pump is not receiving power. Since it's almost 99% a turbo tune, you also probably got an EWS delete chip if you have a silver label 413 DME, right?
If you don't see any power at the fuel pump right when you turn the key to the ON position, then it's a wiring issue (grounds or circular connector). If you see the pulse but the pump does not turn on while cranking, then it's because more than likely the crank position sensor is bad, or the wrong connector was connected to the crank position sensor (such as swapping the ICV for the crank position sensor).
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No, it never was even when it was running NA, wouldnt matter anyway...Originally Posted by e30kid89
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It would be a good and simple indicator to see if your DME was alive or not...
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Yup.
Member
make sure you have a ground from the red/whit to the engine. if you do its missing voltage at brn/grn. brn/grn comes directly from the dme. then check the ecm relay. if thats all good its usually the cps or ews.
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Sorry. Didnt mean to shut down your suggestion so quick, it is a good one but I am reading voltage from the DME relay so that would mean its alive correct?
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Thank you, i will check tomorrow...
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Btw its a 506 dme..
Member
I cant remeber if the brn or the red is ground but you need both for the relay to trigger. brn/grn comes from the dme. so make sure its either positive or negative. either way I had a bad ground strap from the engine to the frame and it gave me the negative I needed on that relay.
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I didn't read the thread so sorry if this is repeat, but a bad cam or crank sensor could cause your problem. There is a little trick that you can use to diagnose fault codes and this should tell us if the crank or the camshaft sensors are bad or any other common fault. Not sure if this will still work in the e30, but it works in am e36. Use the following if you don't have a code reader.
>1* ** * Sit in the driver's seat.
>2* ** * Turn the ignition to the On position (Position 2), but do not start the engine up.
>3 * ** * Your check engine light should be on. If its not on then chances are your DME is bad or it's not grounded properly. If the check engine light is on then your DME is probably ok and its something in the engine bay. Don't confuse the "Check Engine" light with the "Check" light. They are not the same. The "check" light is harmless. don't get confused by any displays on the small computer display below the HVAC controls. Those are part of the "Check" system and have nothing to do with any problems in the engine.
>4* ** * If the Check Engine light is on then turn the key to the off position and remove it.
>5* ** * Read step 6 before performing the following since you need to be very quick at performing step 6. *Re-insert the key and Turn the ignition to the On position (Position 2) again, but do not start the engine up.
>6 * ** * Immediately depress the accelerator fully and release fully 5 times quickly. *You have to do this very quickly.
>7 * ** * Wait for a few seconds and you will see the Check Engine light flash once, then start it will start to blink. All codes are comprised of 4 digits. The number of blinks corresponds to the fault code. For example, ON then pause, ON ON then pause, ON ON ON ON then pause, ON ON ON then off would be a 1243.
>8 * ** * Each four digit code will be flashed sequentially. When the codes start to repeat, all stored codes have been displayed.
>9 * ** * Turn the ignition off. If you got 1243 then the crank shaft sensor is bad and if you got 1244 then the camshaft sensor is bad. 1444 and 2444 means no problem and that is what you hope to find. *If you got anything else then just shoot me the code or go to this website and look in the column M3.3.1 for the code and corresponding error.
> 10 * * * * http://www.bimmerzone.com/category/T...iagnostic.html
> 11. * * If you don't get any codes and the check engine light is working just fine from the troubleshooting above, when you try to start the car does it actually crank over and does it sputter at all or just crank?
>12. * * Have you tried just putting the key in the ignition and turning it to the On position without starting it and listen for the fuel pump? *You should be able to hear the fuel pump prime itself for ~2-3 seconds if you remove the rear seat. *If you can or can't hear the pump that is a good piece of information.
> * * have you checked voltages at the B+ post or at the DME or fuel pump relays. *If the socket that "pin 30" of either of those relays does not have 12v going to it, even with the ignition off, then you either have a burned out fuse (fuses 16, 18, and 28). *If the fuses are ok then you need to check and see if you are getting 12v at the B+ post (thing on the passenger side under the hood where you can jump start your car). *There are two red wires at the bottom of that and they should have 12v to them without the key in the ignition. *If neither of them does or if one of them doesn't then a fuseable link in the trunk is bad. *If the B+, DME relay, and fuel pump relay are getting power then we know they aren't the issue.
Last edited by cragg56; 06-29-2013 at 07:55 AM.
Im HUGE in Japan
Crank sensor? Iirc if it's bad it doesn't send signal to call for fuel. Odd for it to just go.
I play an engineer on TV
I believe bad cps would also cause no spark. Are you getting spark, mike?
Member
I appreciate all the help guys but the car is at the fabricators for the next few weeks so when i get the car back i will inspect further, report back and bump the thread. I am also suspecting a bad engine ground...
Member
Jump the fuel pump relay and start the car.
Last edited by futureroadracer; 06-30-2013 at 12:54 AM.
OLD
E30
636whp
1/4 mile: 10.91@144.38
http://www.youtube.com/watch?v=L_f7fUVqblI
NEW BUILD
335d
520whp
635wtq
120.51mph trap speed
Member
Ok so I pulled a plug and lo and behold no spark. It seems like my dme isn't getting power or isn't grounded correctly. OR, I could have a bad CPS. Quick question. Are there 2 crank position sensors or am I just crazy? One in front of the timing cover and one on the back of the block near the bellhousing?
Im HUGE in Japan
Mike, obd1 runs cps at crank wheel, obd2 cps at rear of block
Member
Ok so since i am s52 obd1 i am correct in leaving the rear unplugged right? If this is the way it should be then i have a sneaking suspicion that i may have switched the sensors on the install. The rear may have not necessarily have worked...
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