Engine K-Light + Fuel Pump Not priming

1. Rob_Quads Newbie Joined: Dec 2002 United Kingdom Posts: 9

   #1 5th December 2004, 02:06

   A friend of mine has a problem with his 1.4 that I have been helping trying to fix and it has stumped me.
   The car recently has been a little rough at starting but nothing major. Has not been turned over for a week or so.
   
   The Problem
   When you turn on the ignition the K-light comes on, on the 2nd click of the key the fueal pump is not priming.
   
   1.I have checked the Fuel pump relay box and it was faulty BUT after replacing it with a new one you hear it trigger when you turn the key but the pump still does not prime.
   
   2.The blue power line to the fuel pump is ground when the ignition is turned on.
   
   3.The fuel level is correct BUT if you try and start the engine it goes to 0 and the warning light flashes.
   
   4.The ECU shows no error - it has been connected up to the Citroen managment console and it shows no problem
   
   5. IF you supply 12v to the petrol pump the car starts and runs as long as you keep supplying petrol
   
   6. If you supply 12v to the petrol pump it continually pumps - normally it stops when it gets up to presure, is this done by the ECU?
   
   7. We have connected up a new ECU and it acted exactly the same
   
   8. Fuses are fine
   
   9. Fuel Cut-off switch OK
   
   Anyone got any ideas on what could cause this?
2. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

   #2 5th December 2004, 02:40

   by the relay box do you mean the sender unit?
   
   Also , when supplying a 12v feed to the fuel pump, does the car try to start and not start as if the immobiliser is stopping it ??
3. Rob_Quads Newbie Joined: Dec 2002 United Kingdom Posts: 9

   #3 5th December 2004, 03:03

   relay box as in the ignition relay box which is located under the ECU - this supplies the 12v for the fuel pump.
   
   If you give it 12v while trying to start the engine starts and runs fine as long as you supple 12v - remove the 12v supple and the pump stops and engine stalls due to petrol starvation
4. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

   #4 5th December 2004, 03:19

   if you are supplying it a 12v feed, is that effectively bypassing the immobiliser??
   Maybe your problem lies there in the second click on the ignition.
5. Rob_Quads Newbie Joined: Dec 2002 United Kingdom Posts: 9

   #5 5th December 2004, 03:28

   immobiliser is in the ECU - its not causing the problem as the ECU is turning on the relay which supplies the fuel pump with power.
   
   Somewhere along the lines he feed is being ground
6. user_3656 Saxperience Addict Joined: Aug 2004 Herts. N/W London Posts: 13578 Project MK4 MoreDoor

   #6 5th December 2004, 03:37

   So , if your hear the trigger from the relay and the fuel pump is working (as you have replaced for new one) surely your problem lies in the connections between the two ?
   Im not to sure , but are the relays separately earthed? and the earth on the pump is ok ?