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I realise that Nick, but even if it doesn't solve the hot start problem it still isn't priming the system like it should and a new relay will fix that.
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At least when you have changed the relay, you can discount it from the equation. I know from your previous posts you've already done the link test, so it's looking more like a relay.
I do agree with Nick T on testing things first. I remember many years back when I was doing my engineering degree, one wise lecturers words
"Never ASSUME anything. It will always make an ASS out of U & ME"
If you still have problems with priming when you've changed the relay, then check its output (at the Relay pin where you link tested) with a voltmeter, before disgarding it.
Best Regards
D
VIN 4532
DOC-574
Sold both of my new relays now but my spare is on hand for testing if you still need it by then matey.
Yes very, very true...
I was chatting to a guy (who will remain nameless) who after replacing his radiator fan switch on his D still had overheating problems. He was told it #must# be the water pump, so off came the manifold, new pump,hoses,sensors etc etc and £800 in parts ....still had the same problem.
Yes you guessed it it was a faulty new rad fan switch .....
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NickT Wrote:..........and just because it's new doesn't mean it will work !NickT
Did you send some signal out to it? Your bloody right, the new relay doesn't work at all, thats going back to the shop!
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Friday the 13th :twisted:
VIN 4532
DOC-574
Posts: 854
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Joined: Nov 2007
Sorry to hear that Dan.
Does it not work at all, or do just as your old one did; not prime?
Best Regards
D
VIN 4532
DOC-574
Posts: 1,272
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Pluged it in and the lights all came on on the dash, the idle speed motor started buzing and the relay itself sounded like a buzzer.
I opened it up and found a short circuit on the board!!! It was brand new!!!!!
I fixed the short and now it works like my original one, but I suspect it being shorted has killed something on it, so its going back to german and swedish on monday to be changed.
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Hi Dan,
Just check you haven't got an electrical fault on your car wiring that killed the original Relay and the new one. As sure as eggs are eggs, if you shortout another new relay you might not get your money back
Hope it's something mate, as these sort of faults really do cause you agro.
Best Regards
D
VIN 4532
DOC-574
Posts: 1,272
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Ive just metered out the connections actually. All seems to be spot on. 12v permanent, earth and 12v switched with the ignition all present and correct. Feed from coil is correct and output to the pump works if you jumper it to the 12v it runs the pump. I'll get them to change the relay for another one. Surely 2 can't be duff.
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Sorry only just caught up with this thread...
I hate to be controversial, but the RPM relay 'priming' is a myth.
The timer circuit inside the RPM relay has a reset circuit, designed to stop the pulse it gives out when you turn on the ignition. Unfortunately the reset period is too short and occasionally lets in the odd ignition pulse from the ignition amplifier module, causing false triggering, leading to this 'priming' effect.
The RPM relay on my D has never done this and it starts on the button hot or cold.
Sorry to be dull, but your hot start issue is 99% likely to be one of the big three. In all cases your metering flap should still offer significant resistance to being pressed down at least 10 minutes after engine off.
1. Accumulator, leading to loss of pressure.
2. Fuel Pump Check Valve allowing fuel back into the tank
3. Primary pressure regulator. Located on the bottom right of the metering head, the o-ring at the back of this usually goes wedge shaped and need turning around or replacing.
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Thanks for that info. I had a feeling the relay wouldn't solve the hot start issue. I was just trying to fix what I thought was another problem with it not priming. A lot of people on the internet seem to think its supposed to prime as well. In that case I'll leave it alone and wait for eurotec to pressure test it
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I bought TWO relays trying to get mine to prime.
A German and Swedish one £19.50, and a Volvo one at £60!
The intermittant starting fault I had did go away when I changed the Relay, so all was not in vain.
So why are there so many references to fuel pump relay priming on the forum if this is a myth?
Or is this a stone I should leave unturned? :wink:
Best Regards
D
PS Hope you problems resolved Dan.
VIN 4532
DOC-574
