1994 BMW 318i Conv. Crank no Start

[sammydeek]

Hello All,

I have an odd one here and believe from my tests that the Fuel pump itself is the root cause even though it was just replaced.

My 1994 E36 318i cranks but wont start and have been working on it on/off for a couple weeks.

Originally the car experienced a crank no start problem and the following were replaced to correct the problem (the fuel pump was the culprit).
- New Fuel Pump
- New Spark Plus
- New Fuel Pump Relay
- New Fuel filter and lines

Result of the above was a success and car ran great for a couple weeks.

One morning I got in and it was back to cranking but not starting.

I thought theres no way it could be the fuel pump as it was just replaced. I went ahead and replaced the Crank Position Sensor and this did not correct the problem. I pulled the Fuel Pump relay and tried the old one I still had on hand and nothing. I bypassed the fuel pump relay completely and still nothing. If I spray starting fluid into the intake she fires and then quickly dies which tells me its a fuel delivery issue.

When I bypassed the fuel pump relay I should hear the pump kick in, especially since I have the back seat out and its in plain site. I'm not hearing anything.

Could it be that this fuel pump that is less than a couple week sold is dead already? Wasn't sure if it was common or not.

Any thoughts or similar experiences?

Thanks for all your help in advance!

[JhwShark]

I would check the contacts and grounds for the circuit. You should hear the pump.

You could unplug the pump and briefly put 12v across it to test the pump in isolation.

[sammydeek]

Thanks for the advice.

When I pulled the Fuel pump back out of the car I realized that the rubber bushings that surround the motor were completely gooey and pieces of it were floating in my tank.

Its a VDO Fuel pump and have requested a warranty replacement which will be arriving today. I have heard that the ethanol thats now present in the gas might possibly be the culprit for destroying the rubber bushings if the gas sits and the car is not driven frequently.

You would think that VDO and other manufacturers would change how they design these things considering this and use a material that can stand up to it.

I will update everyone on the outcome when the pump gets installed back into the car in case anyone else has similar issues.

Thanks!

[sammydeek]

Here is the update:

So the Fuel Pump was replaced and is now functioning but only ran for a few seconds and then stopped. This led me to believe that the pump had fully pressurized the lines and the car still cranks and wont start.

To troubleshoot I first pulled the fuel line on the back end of the fuel pump off and it was pressurized and full of gas. I connected it back up and then cranked the car again...fuel pump stopped. Went back under the car and now pulled the fuel line coming out of the fuel filter and it too was full pressurized and full of gas.

This test let me know the fuel filter was not faulty or clogged.

Now I know I have fuel pressure but am not getting fuel to the engine so assume there's a serious issue with the fuel injectors? Is there anything else that could be causing this?

I am now stumped of than thinking I need to pull the injectors now?

Any suggestions would be greatly appreciated!

Thanks!

[sammydeek]

Another thought of possible cause is the ECU itself since it controls opening and closing the fuel injectors.

I checked for any codes being read by the car and just gave me code 1444 (no codes). Wouldn't a faulty ECU cause a fault to display?

Thanks in advance for any ideas!

[Two Rivers]

The injectors can be checked for power and ground with an inexpensive LED made for this ,You remove the electrical connector and plug it in and crank the engine and the LED should flash if you have a signal from the ecu.You might also check to see if you have 12V at the ecu.