Warm starting problem on TDi75

SimonP

New Member
Hi there. My 1.4tdi has similar intermittent warm start problem. Reading the above it disconnected the can sensor but engine would not start at all. Suspected tandem pump but measured fuel pressure at pump and was above the 3.5bar spec at idle and rose to maybe 4.5bar at faster engine speed. Needle was a blur because of pressure pulses. Anyway I'm wondering if its the cam sensor that will stop the engine starting rather than the crank sensor?
 

depronman

A2OC Donor
Cam sensor will not stop engine starting but it will take longer to start
Only time cam sensor would stop starting is if cam/crank timing is out. Eg belt skipped a tooth or two
Disconnect the cam sensor and try starting. It will take a few more cranks over as no cam sensor telling ecu which cylinder is on firing stroke but once the crank sensor as told the ecu information the ecu works out the firing sequence and engine will start and run fine

The disconnected cam sensor will put the mil light on and from memory will need a code reader to turn it off again


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Freddie Ekberg

New Member
Hi AndyP,
You have exactly described the restart problem I have with my TDI. Did you solve the problem by changing the cam sensor?
 

AndyP

Member
Crank sensors can become faulty when warm
Only when warm, never when hot or cold? I'm 99% convinced this is some type of fuel supply problem as there is no cloud of smoke after 15 seconds of cranking when it eventually starts.
 

spike

Well-Known Member
Only when warm, never when hot or cold? I'm 99% convinced this is some type of fuel supply problem as there is no cloud of smoke after 15 seconds of cranking when it eventually starts.
Any way you can monitor fuel temps to check the sensor is not reading out of range.
Don't know the answer but it may be possible to disconnect the sensor to see if things improve as it's quite common for the output from other temp sensors are used as a back up

Cheers Spike
 

AndyP

Member
Any way you can monitor fuel temps to check the sensor is not reading out of range.
Don't know the answer but it may be possible to disconnect the sensor to see if things improve as it's quite common for the output from other temp sensors are used as a back up

Cheers Spike
That is something I hadn't considered, although I have replaced the fuel temp sensor. I'll have to check whether it can be done in Torque.
 
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