Can you hear fuel pump when turning ignition on ?
#1
Three Wheelin'
Thread Starter
Can you hear fuel pump when turning ignition on ?
I'm in the middle of diagnosing a no start issue after my 99 C2 failed to start.
My question is, when turning the ignition key to on, can you hear the fuel pump operate for a few seconds to prime the fuel lines ?
I know my 944 fuel pump operates for 5 seconds or so after turning the key on (before cranking).
I've checked my fuel pump fuse and that is fine.
I've checked the fuel pump relay and the terminals 30/87 short correctly when 12v is applied across the solenoid coil. So it appears functional.
I've jumpered pins 30/87 at the relay mount and the fuel pump can be heard operating. So it is functional.
However when I turn the ignition key on there is no sound of the fuel pump priming the lines. That surprises me.
My question is, when turning the ignition key to on, can you hear the fuel pump operate for a few seconds to prime the fuel lines ?
I know my 944 fuel pump operates for 5 seconds or so after turning the key on (before cranking).
I've checked my fuel pump fuse and that is fine.
I've checked the fuel pump relay and the terminals 30/87 short correctly when 12v is applied across the solenoid coil. So it appears functional.
I've jumpered pins 30/87 at the relay mount and the fuel pump can be heard operating. So it is functional.
However when I turn the ignition key on there is no sound of the fuel pump priming the lines. That surprises me.
#3
Three Wheelin'
Thread Starter
#5
Three Wheelin'
Thread Starter
As per original post, the fuel pump operates when the relay is bypassed. Even in this condition the car doesn't show a hint of catching.
#6
Yes there is 12V constantly at pin 86 when the ignition key is turned on (and for 10 sec after the key is turned off incidentally). I took it a step further and established that the other side of the fuel pump relay coil (pin 85) is not going to ground (via the DME) during cranking - I thought it would.
As per original post, the fuel pump operates when the relay is bypassed. Even in this condition the car doesn't show a hint of catching.
As per original post, the fuel pump operates when the relay is bypassed. Even in this condition the car doesn't show a hint of catching.
#7
Three Wheelin'
Thread Starter
That is indeed strange. Sounds like the DME does not want to turn on the engine. Have you verified sparks? If no sparks, may be the crank sensor? If there is spark, with the residual pressure after you jump the fuel pump, the engine shoud try to catch. May want to also check the fuel injector and DME relays under the rear parcel.
The fuel injector relay is the one that powers the coil to the fuel pump relay so the fuel injector relay must be working. I'm not sure which dme relay your talking about though.
Trending Topics
#8
Now the fuel injector relay supplies power to the injectors and ignition coils independent of the fuel pump circuit so I think you may want to check it too.
Still, are there sparks?
#10
Three Wheelin'
Thread Starter
However I have subsequently identified the cause of the no start issue. There is water in my fuel - as in well over a litre of water expelled from the fuel line at the filter.
The car actually stopped at the service station, now I know why. We've had very heavy rains here last week and I filled my tank from nearly empty so it seems I ended up with a significant dose of water in the gas.
#12
#13
Drifting
Some of the old style tanks (metal) are rotting out and ground water can get into the tanks through the corrosion or poor/dried out seals. All new tanks are made out of a special plastic material. The pumps draw from the bottom of the tank where the water sits and the first few cars filling up after a storm can get a lot of the water. I'm betting your not the only person having issues. Go back to the station and ask for the name of their insurance carrier and policy number. If they refuse to give it to you - call the head office and demand it. Take your car to a proper service center and have them drain out the gas and run a fuel system check/clean up. Keep a sample of the gas removed along with the car repair service invoice and the gas slip from this station where you bought the gas. You'll need all of this to make a claim.
#14
There is water in my fuel - as in well over a litre of water expelled from the fuel line at the filter. The car actually stopped at the service station, now I know why.
#15
Three Wheelin'
Thread Starter
This pic shows the jars of fuel pumped out of the tank at the fuel filter connection. The jars are numbered in the order the fuel came out. Jar2 and 4 are a different colour because the fuel was pumped into my oil catch can initially whereas the others went straight into the jars. Jar 1 is 99% water and there are decreasing amounts in all the later jars as can be seen in the pics.
I would have stopped at a 'better' gas station but there was 10,600miles between the last gas station and this one so my low fuel light was on.
I would have stopped at a 'better' gas station but there was 10,600miles between the last gas station and this one so my low fuel light was on.