9 replies to this topic

[DarrylB]

Me again, more issues AGAIN!

Last night the car had trouble starting at work, it turned over longer than usual but then fired.

As I was driving home I suddenly lost the throttle and the engine revs slowly died until they got so low that engine stalled. (I managed to coast into a side road)

Using the scan gauge I saw I had a P1512 and that the throttle body didn't initialise.

So today I had a look and tested the brown relay in the boot with a spare car battery, sure enough it was dead. I nabbed a relay from the front relay box and now turning the ignition on I get no codes and can hear the TB do its start up...

BUT I do not get any noise from the fuel pump (no error codes showing)

• I've tested the fuel pump relay and it clicks when 12v is applied
• I've checked every fuse: the 2 in the boot, the two main ones by the window wiper motor and all of them in the front fuse box..
• The fuel cut off switch is depressed.
• There is NO pressure in the rail

SO... is there a way I can run 12v directly to the fuel pump for a brief moment to at least test that it works? Then I can work backwards safe in the knowledge that at least the pump runs

Edited by DarrylB, 10 October 2012 - 05:16 PM.

[leevx2.2]

Put 12volts straight to the pump via relay connector should be the first spade connector as you look at it .

[NickB787]

One thing I found out is when you turn the ignition on the pump runs for a few(ish) seconds then cuts off it will then only run when the engine is being turned over, I thought I had a problem with power to my secondary pump but I was wrong. maybe open the inspection hatch and test with a multi meter when you first turn the ign on or maybe through the wiring at the rear going to the fuel pump relay?

Edited by NickB777, 10 October 2012 - 05:25 PM.

[DarrylB]

Cheers chaps; just so im clear Lee: I've just removed the relay, turned the igniton on and tested that I have 12v across terminals 86 and 85 that the relay would plug into and I do. So do I need to put 12v down the 87 & 30 pins to test the pump? Yeah I was listening out for that Nick but there is nothing, after turning the engine over there is still no pressure in the rail.

[vocky]

if you fit a grey relay instead of the brown relay you will lose the 12v supply to the fuel pump because the brown relay switches two circuits and the grey only one

[leevx2.2]

Don't no the number but if you look at relay holder if the fixing hole is at the back as you look at it the connector closest to you put 12 volts to this and pump will turn on .

[DarrylB]

if you fit a grey relay instead of the brown relay you will lose the 12v supply to the fuel pump because the brown relay switches two circuits and the grey only one

That'll be it then! Poxy relays - bain of my life on this bloody car!

Now to hunt down another brown relay

Cheers Vocky, I wonder how many thousands of pounds, amount of days and peoples sanity you've saved users on here with your wealth of knowledge? I bet the answer is: A LOT

[s-express]

i had this exact issue - exact symptoms, the relay turned out to be ok, it was the wires going into the relay holder, a couple had come out of their holders, so look at that if you haven't already.

[DarrylB]

i had this exact issue - exact symptoms, the relay turned out to be ok, it was the wires going into the relay holder, a couple had come out of their holders, so look at that if you haven't already.

Yup, checked already, it's definitely the relay. Putting 12v across it produces squat, thanks for the suggestion though.

[SteveA]

IIRC the OEM loom for the fuel pump only provides 5v.