Starting problem

[rooksy]

Hello

I'm having starting problems. The car will bump start and run okay after that. I've replaced the battery, checked the speed and reference sensors readings i am getting the correct reading between terminals 1 and 2 on both senders but dont seem to be getting any readings between 1 and 3 or 2 and 3, reading other posts this could be because the values are high and can read as an open circuit (correct me if I'm wrong). I've replaced the DME relay in the past but would like to test this part before buying yet another. Does anyone know how to test this.

Also if I were to replace the reference and speed sensor I cant seem to see where the leads run to and the Bentley guide is very vague.

Any help is most appreciated

Thanks

Sean

Thanks

 

[Geoff_Fields]

If the engine will run after bump starting I can't see how the sensors can be faulty. You have not indicated what response if any you get from the starter motor. Does it crank or click when starting is attempted? If not check for volts at the motor when trying to start engine. Check earth and connections are sound.

 

[chas3.2]

Hi Sean So dose the starter motor turn the engine over ???? Charles

 

[rooksy]

Hi, thanks for the replies. The car turns over and tries to fire (engine shudders then dies) then back to turning over. After a while I managed to get the car running very lumpy at first, but then ticks over okay. I'll check the connections as advised. Could if be a fuel issue - when I first bought the car I had a similar starting issue and changed the fuel filter and added fuel cleaner to the tank? Thanks Sean

 

[Geoff_Fields]

Possibly Mass Air Flow sensor is sticky, which can cause very lumpy tickover and hunting when started from cold. It is sometimes possible to rectify by cleaning the unit.

 

[rooksy]

Hi, Thanks for the advice. I've taken the Air sensor off, the Vane moves freely to open then snaps shut when released. I tried to check the readings as given on page 240-17. I don't get a reading on terminal 3 and ground with the ignition on, terminals 2 & 3 the reading changes constantly as the vane is moved open and closed. Checked Intake air temperature sensor and that read 3.36 ohms. Car is starting after turning over for a short while. Over the last 12 mths I have only done short journeys of 5 miles or under. Do you think it could be a build up of carbon deposits?