Can't hear fuel pump priming

I recently changed the wiring from the back of the ignition barrel on my mk2 8v gti. Now the fuel pump doesn't prime? The lift pump whirrs away but the other one doesn't?

Is it ALWAYS meant to prime?

What could it be? The lights still come on the dash when I switch on the ignition so I'm presuming there is no issue with the new wiring

Cheers

 

Could be wrong but are they not both on same wiring circuit? Does it start and run ?

 

If it hasn't been switched on for a while then they should both prime yes. I'm not 100% sure if it will not prime if you turn on the ignition but don't start it twice in quick succession.

 

The car hasn't been started for six months. It started fine all those months ago! Maybe the main pump has seized?
The electrics are acting very strangely though

For example when I put the intermittent wiper on the oil buzzer sounds! And when the indicators are on the temp light and digital clock flash!!

I will have to check the main pump terminal to see if there is a current there, I ran out of time today.

This project has been a bit of a struggle so far!! ( first proper project though! )

 

I had odd flashing dash lights on the Rocco 16v, which with the telephone support of Rubjonny was tracked down to the brown/white earth wire that bolts to the end of the head.

Fuel pumps do sometimes seize up when they're stood for a long time. you could try to give it a knock with the heel of your hand and see if it wakes up. The old fashioned 'hit it with a mallet' trick is risky on the Mk2 fuel bath though - easy to break it.

 

both the 8v digi and 16v k-jet pumps prime each time you turn on the ignition, they tend to prime for a shorter time the 2nd or subsequent times you try it but you can hear it each time.

 

Was the problem with your rocco the fact it wasnt connected? Cheers

 

Fusebox damage? Sorry to sound naive but will that mean a new fuse box is needed? T

here is a chance that there may have been water ingress as the car has had no windscreen for 3 years and was outside at the previous owners house with only a car cover on.

 

Just had a quick look (in the dark) at the voltage which is present at both pumps. As the lifter pump there is only 0.65v and at the main pump only 0.48v!! So clearly an electrical issue here somewhere! Also now when i put the ignition on the indicators come on and stay on!

Ive sourced a good fuse board so I will have to transfer everything over and see if that works! I'm hoping all my relays aren't damaged! Bad time to have no money when I'm trying to get this car done!

 

forogt to ask, what should there be roughly at the pumps? 12v?

 

You should see ruffly what is at the batt. I would guess something about 13v

 

Ok so there is clearly a big problem here somewhere. Would the fuel pump relay have anything to do with that or is it definitely the fuse board do we thinks?

 

If as you say the car has been getting wet for a while I would say the fuse box is likely to have suffered with rust effecting the terminals. Try pulling the pump relay out and see if the terminals are ok? And test for the volts at the board.

Should you find all is well at the board side of things I seam t remember it is quite east to pop the lid off these relays to see how it looks inside.

Let me know if you need a new relay will send you one down. Got a box full in the garage.

 

Sorry to be a pain but do you know which terminals to test on the board?

I'm thinking it may be the board as this may explain my "weird" electrical happenings! (I hope)

 

If you find the fuel pump relay and pull it out.

Then you could put a jumper wire between the two large terminals that should fire both pumps up.

If this still fails then you need to dig deeper into the fuse board.

 

Right I may give that go tomorrow morning. On one hand I hope it is just the relay but on the other I don't because that wont explain the other electrical gremlins!

cheers for all your help you have been very helpful

 

Cool I have a spare one of those lying about I think. I'll give it a whirl