Author Topic: fuel pump won't prime... manual switch???  (Read 11217 times)

Offline G40supercharged

  • Members
  • *****
  • Posts: 238
Re: fuel pump won't prime... manual switch???
« Reply #15 on: November 14, 2012, 06:07:42 pm »
It does sound like a problem with the ignition switch wiring.

The ECU relay powers up the ECU - it should be closed whenever the ignition is on. Take the relay out and check you get a voltage (12V) to the relay coil when the ignition is on (check Haynes manual for which contacts are the coil in the relay socket). The fuel pump relay coil is driven by the ECU - this will only go off at start up when it primes or if the hall sensor is sending a signal to the ECU as the engine rotates (the idea is the fuel pump will stop spraying high pressure fuel everywhere when the engine stops after you crash and the fuel lines are severed). If you get a spark then the ECU is powered OK (it is still possible for the fuel pump relay to not work if the drive transistor in the ECU is dead - best to only bridge the power switch part of the fuel pump relay socket when testing and avoid connecting any wires to the coil connections as the ECU could be damaged)

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #16 on: November 15, 2012, 12:43:31 am »
Will check this tomorrow :),
Also whilst reading a thread from etches69 I reaad this “can you hear the relays click when the ignition is turned on? if not make sure you have a live ignition feed from the plug by the coil” well I have nothing connected to the plug by the coil :S I have the 3pin connector with black, green and brown wires that sits next to the coil, this has nothing connected to it? I also have a brown 2pin plug with red/black and black wires into it I guess this is what would be connected to the plug next to the coil if I was using the 1.0 loom, so which wires do I need to connect together from the 3 pin plug by the coil and the 2 pin plug?

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #17 on: November 15, 2012, 09:08:19 am »
Will check this tomorrow :),
Also whilst reading a thread from etches69 I reaad this “can you hear the relays click when the ignition is turned on? if not make sure you have a live ignition feed from the plug by the coil” well I have nothing connected to the plug by the coil :S I have the 3pin connector with black, green and brown wires that sits next to the coil, this has nothing connected to it? I also have a brown 2pin plug with red/black and black wires into it I guess this is what would be connected to the plug next to the coil if I was using the 1.0 loom, so which wires do I need to connect together from the 3 pin plug by the coil and the 2 pin plug?

 I had this covered in my topic mate :D

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #18 on: November 15, 2012, 10:12:29 am »
Have you gt a link I followed the one about the wires in the scuttle tray (5pin connecter from the spi loom and the 3pin) but I can't seem to find anything about this plug next to the coil

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #19 on: November 15, 2012, 01:02:04 pm »
 Think I may be close to sorting this, the ecu rely now clicks together however the fuel pump relay clicks on and off really fast making a buzzing noise??? :/ 

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #20 on: November 15, 2012, 04:28:00 pm »
http://www.polog40.co.uk/forum/index.php/topic,8746.msg61862.html#msg61862

That plug i had left i think is what you have next to your coil so you MAY need to splice like i did?

 Clutching at straws, i dont remember my issues tbh.... lol sorry!

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #21 on: November 16, 2012, 08:26:55 am »
This is the thread I've followed but its a different plug that I have by th coil, its a brown plug with 2 wires red/black and black, on the spi loom it would plug into a 2pin plug by the coil but now with the g loom the plug by the coil is a 3 pin black plug with black, green and brown wires so I've connected black to black, green to red/black and earthed brown the relays now click but the fuel pump one goes mental and clicks on and off rapidly intill you turn the ignition off :S

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #22 on: November 16, 2012, 08:56:03 am »
Have you pulled the SPI engine loom completely out? half the brown plug is in the engine loom and the other half is on the car loom.
 IIRC its the sidelight plug and the brown plug people get mixed up. make sure you havent plugged your brown into something else. My loom is inside so i cant reference you any ''real'' pics BUT.....
 The below link takes you to a picture of my SPI loom plug, check the background of said pic and you'll see my brown plug.
 Now said brown plug isent a straing fit iirc, i had to cut 1 plug off my G loom (irc) and fit the brown other half onto the wires.... I'll see if i can see what colours what under the dash later.
http://i134.photobucket.com/albums/q89/photo123_2007/Polo/IMG-20120721-00529.jpg
« Last Edit: November 16, 2012, 09:16:30 am by POLOMON »

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #23 on: November 16, 2012, 09:15:09 am »
SPI loom can be thinned down, iirc on that loom you need a couple of plugs, one being the plug that goes by the throttle body on the SPI, this plug:

On this plug there are a few wires you NEED:

 2x oil pressure sensors (Blue with black tracer and yellow with black tracer)
Fuel pump lives (Red with yellow tracer)
White with yellow tracer is diagnostics plug, you can fuck that off for now, however i could wire mine in as the wires were there....

When i wired mine these threads REALLY helped me out also mate:

http://www.polog40.co.uk/forum/index.php/topic,211.0.html

http://www.polog40.co.uk/forum/index.php/topic,214.0.html

 there was alo a thrwad by cheys03 which sods law i now cant find! i'll have another look....


Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #24 on: November 16, 2012, 09:27:58 am »
Not sure if it helps you out actually looking at it but this it the thread I thought was cheys03's

http://www.polog40.co.uk/forum/index.php/topic,6354.msg45662.html#msg45662

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #25 on: November 16, 2012, 12:47:22 pm »
Yh that brown plug is the one but I dnt have a clue what to wire it to? I have done the same with the 5pin plug
Really appreciate all the help btw :) 

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #26 on: November 16, 2012, 01:10:33 pm »
Read my thread again mate :p this is the issue i had.... remember before you said you didnt have a black plug like the one i had? well i think that black plug goes to the brown..... have a read of my thread and the one posted by G40_AD its all there :D

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #27 on: November 16, 2012, 07:02:39 pm »
I can't find it anywhere in your thread (I'm probably being blind :S), I've done the same thing as you with the plug for fuel pump, oil sensors, diagnostic and the spare red/black.
I'm basically in the same situation as g40 ad's thread but the brown plug that's in his scuttle tray is down by my coil but there no solution on the thread and I can't find the one mentioned on club polo (doesn't help only being able to use my phone). I hate wires :( :L

Offline POLOMON

  • Members
  • *****
  • Posts: 170
Re: fuel pump won't prime... manual switch???
« Reply #28 on: November 16, 2012, 09:29:05 pm »
Well G40 ad's engine is now mine, tbh I was in the same situation as him.... Just looked under my dash and I have a brown plug labelled coil. The other half of said brown plug goes to that black plug ad sais what's this for if I remember correctly.... There's a green wire and a black wire in the G loom iiirc on a plug ythat reaches to the coil. My brown plug is soldered onto these two wires and then plugs into the other half of the wires. Green goes to red black tracer and black to black. Tother iirc on the 3 way is earth my memory is very vague on this as I did it a while ago and tbh I'm crap at wiring haha. Always good to know when I'm trying to help ay lol....

 Work through wire by wire on the ecu pin out and find out which is which and see what you have left. I started with that and got as far as the issues I mentioned.
« Last Edit: November 16, 2012, 09:44:27 pm by POLOMON »

Offline Craig g

  • Members
  • *****
  • Posts: 103
Re: fuel pump won't prime... manual switch???
« Reply #29 on: November 17, 2012, 11:49:27 am »
Just tried this and still no spark or fuel pump I think it must be something to do with the power to the relays because If I put power straight to them then everything works, if anyone lives near shrewsbury and wants to help make another G live I'll happily pay you for your time