318is wont start please help

[mitch_ells]

I have a 94 318is automatic and i replaced the fuel pump fuel filter and crank positioning sensor. and now the car wont start
i thought it was the fuel pump but it didnt start then i replaced the sensor i wont start but it gets the gas and it get the spark but it wont start.

[nos]

From what I know, the crank sensor is monitoring the rotation of the crankshaft, data is used by the system to control ignition timing. You didn't say if your 318 didn't want to start before you changed those part or after, or else.It's an important information.
The fuel pump is very important, because if it does not provide the proper fuel pressure, the engine will not be feed with fuel. (even if you hear the pump when you turn on the ignition).
You have to check first the fuel pump pressure and make sure that is the proper one. And sorry about that but if the pump is ok, and everything is plugged correctly, the only chance to find out what'swrong is to do a full engine diangosys, especially to check and monitor the crank sensor's data. Hope this will help you.

[mitch_ells]

well before we changed anything it just cranked over. i got the right one. but we changed the crank position sensor. what will it do if the ecu is no good in it.

[wolfie359]

Well.. if you KNOW you have fuel, and you KNOW you have Spark at the plug, Then the car WILL at least Sputter when you try to start it, unless of course your cylinders are just that full of fuel, in which case pull the fuel pump relay (little blue one mounted to the side of the fuse/relay box under the drivers side rear of the hood), and turn it over for a good 30-45 seconds total letting the starter cool for a few seconds in between, then put it back in and start over.

If it sputters but still doesn't run, you may have an Air problem in which case check the Mass Air Flow and Manifold Air Pressure sensors. Don't just replace every sensor you feel may be bad, get a Chilton's for your car, it will tell you how to test each sensor before replacing it, theres about $1500 to $8000 in sensors on most cars from 1987 and newer when most companies got rid of the everlasting carb...

Hope that helps a little...