Hi all,
I am having some issues with my M42 318is.
It developed a poor idle and would cut out occasionally. In order to help cure the issues I,
removed the heater plate and associated pipework
Cleaned the ICV but is wasn't rotating smoothly so i bought a new one.
New cam sensor.
Injectors cleaned
Boot from afm to intake manifold replaced
I measured the resistance on the tps and it was a bit out so I replaced it with a used item, no change
Swapped the ecu with a spare, no difference
Now the engine runs with a fairly smooth idle for a few minutes but then starts to die as if it's not getting enough fuel. If I rev the engine, it revs fine but cuts out as soon as i release the throttle.
It seems to be getting plenty of fuel. The pump runs continuously.
Anyone any ideas?
If the crank sensor is faulty does it cut the fuel pump or injectors or would a faulty fpr show similar symptoms? There is no petrol coming out the vacuum line of the fpr.
If I unplug the afm, the car runs but very poor idle. Does anyone know the pins and resistance required. There seems to be mixed info on the net.
Thanks
William
318is cutting out.
Moderator: martauto
-
Brianmoooore
- E30 Zone Team Member
- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
You seem to have checked just about everything, except what I'd consider to be the most likely suspects!
These are the crank position sensor, the DME relay, and the (blue) coolant temperature sensor. Which of these is most likely is difficult to tell from here, without actually experiencing the fault.
The temp. sensor should measure about 300 ohms at full engine working temperature, and about 4000 ohms (at this time of year) with the engine stone cold. Ideally these measurements should be taken at the relevant pins of the engine ECU plug, so that the wiring loom and any possible faults in it, are included in the results.
DME relay (white one under the bulkhead wiring cover) is easily checked by bypassing it with two wire links. Pull out the relay, identify pins 30 and both 87s of the socket, and link these three pins together with two pieces of wire. Don't park up the car and leave the links in place, since this is the same as leaving the ignition on.
A duff crank sensor kills the fuel pump, injectors and sparks, but as they start to fail, they normally only drop out intermittently, getting worse as they absorb heat from the engine.
A good crank sensor measures about 550 ohms across two of its pins, but a result of about this does not confirm a working one. Only if the measured value is very different from this, or varies wildly as the wire is moved near the sensor, can a duff one be confirmed.
These are the crank position sensor, the DME relay, and the (blue) coolant temperature sensor. Which of these is most likely is difficult to tell from here, without actually experiencing the fault.
The temp. sensor should measure about 300 ohms at full engine working temperature, and about 4000 ohms (at this time of year) with the engine stone cold. Ideally these measurements should be taken at the relevant pins of the engine ECU plug, so that the wiring loom and any possible faults in it, are included in the results.
DME relay (white one under the bulkhead wiring cover) is easily checked by bypassing it with two wire links. Pull out the relay, identify pins 30 and both 87s of the socket, and link these three pins together with two pieces of wire. Don't park up the car and leave the links in place, since this is the same as leaving the ignition on.
A duff crank sensor kills the fuel pump, injectors and sparks, but as they start to fail, they normally only drop out intermittently, getting worse as they absorb heat from the engine.
A good crank sensor measures about 550 ohms across two of its pins, but a result of about this does not confirm a working one. Only if the measured value is very different from this, or varies wildly as the wire is moved near the sensor, can a duff one be confirmed.
Thanks for the reply Brian.
I forgot to mention that I have changed the blue temp sensor with a new one as well. I did check it though with the engine cool but not fully cold, 900 ohms.
Bypassed the dme relay, no difference.
I got a spare used crankshaft sensor from my brother. 500 ohms across the pins, same as my own. Fitted it but no difference.
Also took a spare sent of leads and put them in incase but no difference.
However, when I plug out the icv, the car idles lower but when I rev it, it doesn't cut out when the revs drop. It's a new icv, spurious but thought it should be ok.
Is there any way of testing the icv?
I forgot to mention that I have changed the blue temp sensor with a new one as well. I did check it though with the engine cool but not fully cold, 900 ohms.
Bypassed the dme relay, no difference.
I got a spare used crankshaft sensor from my brother. 500 ohms across the pins, same as my own. Fitted it but no difference.
Also took a spare sent of leads and put them in incase but no difference.
However, when I plug out the icv, the car idles lower but when I rev it, it doesn't cut out when the revs drop. It's a new icv, spurious but thought it should be ok.
Is there any way of testing the icv?
Thanks for the reply Brian.
I forgot to mention that I have changed the blue temp sensor with a new one as well. I did check it though with the engine cool but not fully cold, 900 ohms.
Bypassed the dme relay, no difference.
I got a spare used crankshaft sensor from my brother. 500 ohms across the pins, same as my own. Fitted it but no difference.
Also took a spare sent of leads and put them in incase but no difference.
However, when I plug out the icv, the car idles lower but when I rev it, it doesn't cut out when the revs drop. It's a new icv, spurious but thought it should be ok.
Is there any way of testing the icv?
I forgot to mention that I have changed the blue temp sensor with a new one as well. I did check it though with the engine cool but not fully cold, 900 ohms.
Bypassed the dme relay, no difference.
I got a spare used crankshaft sensor from my brother. 500 ohms across the pins, same as my own. Fitted it but no difference.
Also took a spare sent of leads and put them in incase but no difference.
However, when I plug out the icv, the car idles lower but when I rev it, it doesn't cut out when the revs drop. It's a new icv, spurious but thought it should be ok.
Is there any way of testing the icv?
I tried to spray carb cleaner around but didn't notice any. I got rid of a lot of the excess pipes when I removed the heater plate. Fitted some new pipes too so not impossible but unlikely but will check again.
May check the afm too.
May check the afm too.
