Firing Problems

e21rana · Post by **e21rana** » Wed Mar 23, 2011 11:46 am

My car is not firing up. I noticed that there was no fuel going into the engine so I checked the fuel pump and gave it direct 12v and it started working. And then I noticed that I wasn't getting any spark from the plugs. I took one of them out and put it to the body and clicked the ignition to check if it was sparking...nothing. I also noticed that all of them were quite black so I deciced to change them all. Why isn't the fuel pump turning on and why am I not getting and spark.

e21-Mark · Post by **e21-Mark** » Wed Mar 23, 2011 3:25 pm

Coil could be knackered? Or leads maybe? Have you checked fuses & relays for the fuel pump?

e21rana · Post by **e21rana** » Thu Mar 24, 2011 1:48 am

Fuses and relays seem to be fine and the leads. Someone mentioned the crank sensor to me. Could it be that?

murran · Post by **murran** » Thu Mar 24, 2011 1:57 am

crank sensor? have you got an e30 engine in yours now?

e21rana · Post by **e21rana** » Fri Mar 25, 2011 12:41 pm

yup iv got an e30 2.5 lump in. Having some serious issues

murran · Post by **murran** » Fri Mar 25, 2011 8:05 pm

not having a spark, the fuel pump not having a live while cranking and no spark are all signs the crank sensors not working for some reason.
the the large permenant lives into the motronic loom are they all attached?
simple mistakes first.... have you mixed up the crank sensor plug with the cylinder recognition sensor plug (the three pin plug coming off the plug lead no 1)? they do plug into each other so easily mixed up.
the crank sensor is a powered sensor. so one wire should be live the other will be earth and one signal wire. with the ignition on check the live and earth is there?.
also have you disturbed the sensor mounting bracket itself from when the engine was running before in the car it came from. the clearence gap needs to be pretty exact or the ecu cant pick up the wave.... the bracket is what adjusts it, from memory the clearence needs to be around 0.8mm (?)

e21rana · Post by **e21rana** » Fri Mar 25, 2011 11:15 pm

Thanks murran I think I need to check my crank sensor and change it. This is how it started...I left the car running for a while and then suddenly it cut off. I thought it may have been that I ran out of petrol. But that wasn't it and that's when i realised that the fuel pump was working and no sparks. I think it may just be the crank sensor.

murran · Post by **murran** » Sat Mar 26, 2011 1:33 am

so it was running, then cut out?
well the wiring side of of it should be fine then. is there no live to the fuel pump when cranking then and no spark either?
when you put the ignition on, check it gives the live to the crank sensor and the coil.
on cranking the ecu needs to see the crank sensor signal..... it sees no1 (the gap on the crank pulley), then and only then, it gives the live to the fuel pump, starts the injectors, and switches the coil (earth side, to make the spark).
the ecu it all run off the crank sensor.......
if a new one doesnt work, and the gap is correct. then check the shielding on the crank wire is earthed. (its earth shielded to stop interferance) id replace the sensor before checking this as its v unlikey.

e21rana · Post by **e21rana** » Thu Apr 14, 2011 8:26 pm

UPDATE! I have changed the crank sensor to a brand new one and still no spark or fuel. The only other thing left for me to check it the relays but I pretty sure it can't be the relays. Suggestions please......

Mobster · Post by **Mobster** » Fri Apr 15, 2011 11:05 am

I would change the Coil and disi just to make sure. The Fuel pump might be a red herring here. This really is a tick box excercise i think.

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