Author Topic: Wont Start Fuel Related (Read 3046 times)

Haggis · « **on:** July 10, 2008, 09:13:57 PM »

Hey, I recently bought a 91 318is, the car will crank with power but wont start, I went thru this thread http://www.m42club.com/forums/showthread.php?t=5462&highlight=fuel+pump+start

and figured out the wire to the pump has a short so it won't supply power to the pump, I tested the relay it was good, tested the cps from the fuse box to which I believe is good, so i hooked up 12v straight to the pump, started to pump fuel to the engine, but when i try and start it, it seems it still isn't getting fuel, I took a spark plug out, tested it and turned out good, put it back in and when I gave it power it sounded normal so I don't think its the spark plugs, is there a way to check if the engine is getting the fuel I'm pumping to it?

Jimmy Lewis · « **Reply #1 on:** July 10, 2008, 09:37:25 PM »

Well, do you even know if the pump is running with the car running? It should run on accessory mode. You could start the car and run it, then remove a plug wire, let the engine run a bit longer, and check the plug for fuel. That would be the way I would do it, though there is probably a better way. If the pump is running and seems to hold pressure, I would replace the fuel filter as just a preventative measure, to rule out. Besides that, report back to us with a bit more detail on what is going on and maybe we can figure it out.

Haggis · « **Reply #2 on:** July 10, 2008, 10:11:08 PM »

Quote from: Jimmy Lewis;53101

Well, do you even know if the pump is running with the car running? It should run on accessory mode. You could start the car and run it, then remove a plug wire, let the engine run a bit longer, and check the plug for fuel. That would be the way I would do it, though there is probably a better way. If the pump is running and seems to hold pressure, I would replace the fuel filter as just a preventative measure, to rule out. Besides that, report back to us with a bit more detail on what is going on and maybe we can figure it out.

The car wont start at all. At the moment I have 12v from an extra battery I have that powers the fuel pump, What I need to know is if there is fuel getting to the cylinders, and if I need the Fuel Pump Relay connected to the pump or will the pump, pump fuel to the engine regardless?

Haggis · « **Reply #3 on:** July 10, 2008, 10:43:28 PM »

Does anyone know where the Crank position sensor is located on the engine?

nicknikolovski · « **Reply #4 on:** July 11, 2008, 04:08:14 AM »

The CPS is located at the bottom of the lower timing case. It is held in a bracket next to the crankshaft vibration damper. However the wiring where you test for resistance is up higher near the intake manifold. Just follow the wiring harness from the sensor up to the connector.

Haggis · « **Reply #5 on:** July 11, 2008, 08:33:02 PM »

I'm sorry, I must be blind. I can't seem to find the sensor. I know it might be a bit much to ask but would anyone happen to have a picture of where it is located? It would be a great help because I am almost certain it is what I need to replace for my car to start.

nicknikolovski · « **Reply #6 on:** July 11, 2008, 10:35:19 PM »

Right, remove the fan shroud, jack the car up at the front, slide under the front of the engine, and you should be able to see the crank pulley, then look for a sensor pointing at the toothed part of the crank pulley. It is on the A/C compressor side. I can't get a picture at this time though.