Thread: Help please - my poor old Rangie won't go

Id open up with the flapper unit not reading correctly or being stuck.

Thanks Dave for the quick reply.

I have just pulled off the flapper valve, and it's movement seems silky smooth. Are there any other checks I should do while it is off?

Any other suggestions please?

Thanks,

Paul

yes while its off you want to hook up a very sensitive multimeter to it and watch the resistance scale this will highlight if its having hassles or not esp if the numbers jump around erattically.

I have measured the voltage from pin 7 to pin 9, and it varies smoothly from 3.7 volts to 1.6 volts as I move the flap, as per manual.

The manual says there should be 1.55 volts from pin 6 to pin 9, and 4.3 volts from pin 8 to pin 9. These voltages are transposed on mine, but I think it is probably a typo in the manual as the voltages co-relate so closely.

By the way, what is the little motor under the bonnet that starts whirring away when I move the flap from rest?

Cheers,

Paul

By the way, what is the little motor under the bonnet that starts whirring away when I move the flap from rest?

Hopefully it's not under the bonnet. The fuel pump is activated by the air flow meter opening ie when the engine starts. This follows the 1.5 secs or whatever when the ignition is turned on.

Re the richness. I would look at the temperature sensor.
There are only a few things in injection that cause the injection to run rich.
1 The temp sensor giving high resistance. This could be a dirty contact
2 Limp home when there is no signal from the air flow meter, but this is not black smoke rich.
3 high fuel pressure from a failed fuel pressure sensor.
4 The cold start injector leaking
5 an injector seized open. This happens mainly on LPG cars.
Other failures like the ECU would tend to drop one bank or similar.
Regards Philip A

Hi Philip,

Thanks for the reply. Hmmmm - I am certain that whirring noise was under the bonnet, or in the cabin, definitely not the fuel pump! At first I thought it was the heater fan or air-con fan. Very peculair indeed.

Also, I have an immobiliser that works only on the fuel pump. It was in the OFF position.....

I doubt if the fans are controlled by the ECU or I would suspect that it was getting confused in its instructions. I wonder if there could possibly be a short circuit somewhere, all very strange. I will identify that noise and go on from there.

I am not certain that the richness and the current refusal to start are the same cause, but it does seem likely.

I'm a bit stumped on this. Carbies, points and compression are so easy - one can always get the buggers to go.

Cheers,

Paul