Neither fuel pump running 16v

[casinoblue]

hey guys,

have tried searching, but can't find a similar problem.

mk2 16v gti has been stood in the garage for about six months. charged the battery last night and tried to start it this morning. Neither the lift pump or main pump are running, so the car starts and dies immediately. The main pump is not priming with ignition, although the relay is clicking on and then off after 2 seconds as normal.

have tried another relay, and checked the fuses still nothing.

there is 10V to the lift pump coming in on the violet wire on the 4 pin connector, but nothing on any other wires and nothing going into the main pump.

have checked the fusebox by removing the relay and checking for battery voltage across the connectors as is says in the haynes manual. It also says to check the hall sender and ignition switch unit. how do i check these and is it likely that they are the cause of the problem?

anything else i can check would be much appreciated.

thanks,
james.

[casinoblue]

anyone had a similar problem?

really need some advice on this, probably going to have to sell the car soon due to a house move, and don't want to sell as a non-runner.

any help would be appreciated,

thanks

[Ben Lessani]

Remove the fuel pump relay, bridge the two BIG pins with a sizeable wire (at least 12 AWG) and see if the pumps start running. If they don't, then connect a multimeter to the +12v and GND of the main pump (under floorpan) and see if you have 12v. I had to replace the GND on my main pump to get 12v going through to it properly. If you have 12v at the pump, but it isn't making a noise - you're going to have to remove it and test it off the car - just make sure you don't let the pump run dry - it must be immersed in fuel, and for the love of god, don't ignite the fuel off a spark!

Mine doesn't prime on IGN because the 555 timer in the relay died a long time ago, but when the engine is running, it works fine.

[casinoblue]

thanks Ben,

will try bridgeing the relay when i get chance. Did try another relay though with no affect.

cheers 

[rubjonny]

if the fuse is deffo ok then you have a break in the wiring, if you check the yel/red it should be live when the relay clicks, but this means you have to be quick if you want to check it

if you pull the fuse out check for 12v at the fuse slot pins when the relay clicks, and check the fuse with a multimeter to make sure it doesnt have a hairline crack.  See the fusebox faq for the fuse locations, its in the mk2 maintenance section

[casinoblue]

thanks rubjonny,

it's definitely starting to sound like broken wiring, which i was dreading. the back of my fuse box is a bleedin nightmare, somebody hacked into it to fit old alarms, amps and god knows what else, and made a right mess of it

fuses are defo all ok continuity wise, buzzed them all with a meter. also tried to get continuity between feed to main pump and the connectors on the back of the fuse box, but couldn't get it on any pins...............more evidence of broken wires

where does the feed to the pump come out of the back of the fuse box? checked all the pins on the two main connectors in the centre of the fuse box (labelled D & E i think) as these are listed as containing rear loom etc.

sorry if i'm being dumb, want to make sure i'm checking the correct wires before i replace them.

thanks,
james.

[rubjonny]

have a look in the fusebox faq, has a complete listing of all the pins on both the early and late fuseboxes.  has pictures too so you can id which fusebox you have

[jimojameso]

U sure the pumps not knackered? Put 12v straight onto the main fuel pump to see if the pump actually works. I restored an old mk2 that hadn't run in ages and the pump didnt work but was fine when it was last used.