no it wont break the circuit, but it will stop the injectors working and cause the original problem you had. if the fuse is ok then fix the broken wire and move on. if you pull the fuel pump relay, you'll note 2 of the terminals are larger than the others, get a chunky bit of wire and bridge these 2 sockets on the fusebox, this should trigger the fuel pump.
I'm getting 12v from the relay on the fusebox, I've tested the continuity of the wires going from the back of the fuesbox to the pump and they are fine, changed the fusebox just as I had a spare one lying around. Stripped my immobiliser down but it doesnt have a fuel cut off...just a starter and ignition cut offs... I've sent power down the line of the fuel pumps and they are working... next to be swapped is the ECU as soon as that arrives in the post. The wires going into the fuel rail come from / are controlled by where???
Also tested the power coming out of the back of the fusebox and not getting any power from the pin for the live to the pump... does the ecu tell it to fire on start up???
okay im struggling to find the fault now... so far i've tested and replaced the following... 1. Fuel pumps tested & working 2. Brown/Red & Brown wires from fusebox to fuel pump tested for continuity and all good 3. Relay 167 tested and working and replaced 4. Relay slot tested and getting 12v 5. Fusebox replaced to eliminate that. 6. Fuel Rail tested for continuity and working. 7. ECU Replaced 8. Immobiliser removed even though it has not fuel cut off. 9. Tapped into ignition live to supply power to fuel pump live on back of fusebox and can get car started but the fuel pumps stay on and car cuts out after a few seconds. What controls the fuel pump other than a relay and 20amp fuse??? When the car was fully working if I switched the ignition on, the fuel pumps would prime the engine and then switch off before fully starting the car... how is this momentary power controlled??? is it the relay that does that??? Help!!!
fuel pump is controlled by the ecu. check the red/yellow fuel pump relay trigger wire from the ECU, you'll find a multi plug next to the ECU, start there!
The fuel pump relay solenoid is supplied by the ignition switch 12v supply and earth controlled by the engine ecu. The two large relay terminals are just a switch that supplies the fuel pump. When the ignition is turned on you should get 12v across the 2 small relay terminals for a couple of seconds, this energises the solenoid and activates the switch. Always check voltages with components plugged in. I think you need to go back to the start, you can't have 12 v at the relay and not at the pump if you say the wiring to the pump is o.k.
Red/Yellow seems all fine from G1/3 right up to the ECU... ...now I'm going insane... I've read TSC's post from 2004 and the he had a similar problem that he only resolved after replacing the Loom... I cant really afford to do that but it seems my only option at the moment...HELP!!! I can get the car running for a few secs if I feed a +ve line into the fuel pumps but on ignition I get no prime... I'm gonna take the dash out (When the feckin rain stops!!!) and see if I can see if I've spliced anything when replacing it a few months ago!
sometimes its easier and cheaper in the long run to bite the bullet and get a mobile electrician round to sort the fault. sounds like youve tried a lot of things which leads me to believe its something very simple i had a 1991 16v gti which intermittently had this fault so bought a fuel pump relay but never got round to fitting it before i sold it
Yeah the wiring is a bit of a nightmare on these. I've had poor connections at the fuse box causing problems with the fuel pump relay. After removing and refitting the connectors it worked fine. I don't think you need a new loom just a wiring diagram, multi meter and some methodical checks. Every problem can be fixed. Hang on in there.
Okay maybe I'm getting somewhere....I've discovered that I'm getting NO POWER at the fuse...No.18 (20A) ...does this mean anything to anyone???
no because it should still p[rime the pump on 1st turn of key, and dizzy wont be spinning when that happens #18 is fuel pump fuse, no power here means relay isnt activating. You have power to the 30 socket so thats fine,m its either ign live or earth trigger from the ECU. you're gonna have to stop messing about and pull out the ecu and check all the pins with a multimeter! get the haynes out, last 2 diagrams in the back are for the digifant 8v, just ignore the lambda sensor bit as you dont have one.
RJ - I wish I was messing about!!! LOL Will grab the haynes in a bit....what am I testing for voltage, ohms, continuity??? All of the above???
Although I must admit I did have fun pulling the spare CE2 fusebox apart earlier trying to track what goes to what!!!
depends what pins you're testing haynes should make it pretty obvious, but pm me your email addy i have a diagram that shows where all the circuit traces inside the fusebox go
The diagram I have is a bit old and fuzzy, however. Test for 12 v to fuel pump relay, one of the large terminals should have 12v to it, use a good earth point. This will confirm the feed. As rubjonny said, you will not get 12v at fuse 18 unless the relay is switched by the ecu. With the ignition on you should have 12v at one of the small terminals on the relay, again use a good earth point. If you have both of these then the ecu is not switching the relay. Have you checked the ecu live and earths. If the ecu is not powered it will not switch the relay. Also make sure your battery is staying charged while you do these test. Best of luck.
