Yet another problem

[Arctic]

Hi Martin.
As above by Mike but with photo of said electrical plug to remove.
1

2

Fuel line to put into bottle and make sure the flow is good without spluttering, if spluttering them UBP is not great.
3

Another thing to take into account is the HPFP regulator O-rings they can fail, easy fix at low cost of about £5.22p
https://www.ebay.co.uk/itm/335297736474

[Martin Butler]

Thanks, luckily a friend was passing who is a mechanic, and with a few tests, he confirmed its the in-tank fuel pump theres nothing coming up from the tank, so i will order a new pump, has anyone got a idiots guide as to how you change the pump over, once its out of the tank.

[SD1too]

Originally Posted by Mike Noc

Not on the diesel engine Dave ... If you then move the key to position III they will run again to allow the engine to start.

To avoid any confusion or doubt, this is what I said in post no. 9.

Simon

[Martin Butler]

A bit of an update, Someone local to me made me an offer for the car as it stands, not as much as i expected, but I accepted, my new car, an MG F is being delivered on Friday, So thank you everyone for your help, its been much appreciated, I'm going to stay with the club, if i'm allowed to, but i'm still part of the rover/ MG scene, for those who might have an interest, its the 1.8 vvc and has done only 74000 It's going to be weird seeing my 75, being driven by someone else.

[BRG75]

Hi Martin,

Sorry that I obviously missed this post, nearly a week ago.

Sorry also that you've decided to part with your 75, but you've certainly had a run of bad luck with it.

Do stay in touch, as you've said, and an MG F will always be welcome at the SE meets.

Cheers

Mike

[Mike Noc]

Originally Posted by SD1too

To avoid any confusion or doubt, this is what I said in post no. 9.


Simon

No it isn't Simon. This is what you said in post #9:

Originally Posted by SD1too

Turn the ignition key to position 3 so that the engine turns over Martin. Is/are the fuel pump(s) running now? Ask an assistant to operate the key whilst you listen or use a multimeter. If the pump(s) are running when cranking then the crankshaft position sensor is o.k.

Simon

As mentioned, this is not a valid test for determining a faulty crank sensor on the M47R engine.

[SD1too]

Originally Posted by SD1too

Turn the ignition key to position 3 so that the engine turns over Martin. Is/are the fuel pump(s) running now? ... If the pump(s) are running when cranking then the crankshaft position sensor is o.k.

Originally Posted by Mike Noc

... this is not a valid test for determining a faulty crank sensor on the M47R engine.

Hi Mike,

Are you saying that if the LP pumps don't run during cranking then the reason could be something other than a faulty crankshaft position sensor?

Simon

[Mike Noc]

No I'm saying that the pumps start running at key position II so are running before the engine starts to crank and therefore have nothing whatsoever to do with the crank sensor.

If you allow the pumps to time out and then try and start the car the pumps will start up again but l would have thought that they are getting the signal from the key being moved to position III. The evidence for this is that if you stall the engine the pumps will continue to run, and if they were dependent on the crankshaft signal then they should of course stop.

[SD1too]

Thanks for coming back on this Mike because the diesel in fact behaves in almost the same way as the petrol engines.

Originally Posted by Mike Noc

No I'm saying that the pumps start running at key position II so are running before the engine starts to crank and therefore have nothing whatsoever to do with the crank sensor.

That is indeed correct according to RAVE. At key position II (ignition on) the ECM energises the LP pumps directly to achieve a pressure of about 2.5 bar. The crankshaft sensor is not involved at this stage as you've said.

However, and this is the important bit, as soon as the key is advanced to position III (cranking) the pump supply from the ECM is dependent upon a signal from the crankshaft sensor. This is exactly what I said in post no. 9 and which you have disputed. Have a look at RAVE page 18-1-13 which says this:

"The signal from the CKP sensor is required by the ECM for the following functions: ... To enable the fuel pump relay circuit (after the priming period)."

Originally Posted by Mike Noc

If you ... try and start the car the pumps will start up again but l would have thought that they are getting the signal from the key being moved to position III.

The ECM has two requirements to start the engine:

1. The ignition key turned to position III (cranking) and ...
2. The ECM receiving a signal from the crankshaft sensor.

The pumps are not supplied directly from the ignition key switch as I think you've supposed. The ECM receives a signal that the key has been moved to position III (cranking) and it then looks for an output from the crankshaft sensor.

Originally Posted by Mike Noc

The evidence for this is that if you stall the engine the pumps will continue to run, and if they were dependent on the crankshaft signal then they should of course stop.

If the engine stalls then the crankshaft sensor signal of course ceases but since the key is in position II the conditions are satisfied for the pumps to be primed by the ECM. That is why you hear the pumps running.

I hope that this satisfactorily explains why what I said in post no. 9 is correct and it is a valid test for the crankshaft sensor on the M47R diesel engine.

All the best,

Simon

[Mike Noc]

CanI suggest you carefully read what you have written above and you'll see that what you wrote in post #9 is incorrect.