fuel pump electical feed
fuel pump electical feed
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Discussion

old64er

Original Poster:

1,388 posts

262 months

Saturday 12th March 2005
quotequote all
After putting the engine in the S1, i have gone to start it and the fuel pump doesnt prime?

I have checked the pump and wiring to it from the relay and its ok.

How does the pump circuit switch on and off at a certain pressure and where is the pressure switch fitted?



GreenV8S

30,999 posts

308 months

Saturday 12th March 2005
quotequote all
It is a continuous flow system. The pump runs continually (while the engine is running) and feeds full flow to the engine at all times. The excess fuel is returned to the tank via a mechanical pressure regulator (variable restrictor) which controls the pressure in the fuel rail.

On the V8 cars the fuel pump is controlled by the ECU via a relay, there are also a couple of fuses, an inertial cutout and the alarm/immobiliser in the circuit. A fault in any of these would prevent the pump from working.

As a quick sanity check I suggest you take a direct fused 12V supply from the battery to the +ve terminal on the fuel pump. If the pump runs you know there is an electrical problem which can be tracked down easily enough. It's also good enough to start the engine and get you home like this, if you're stuck. Just remember to disconnect the pump after you park!

If the pump still doesn't run, either the earth is bad or the fuel pump is dead.

old64er

Original Poster:

1,388 posts

262 months

Saturday 12th March 2005
quotequote all
GreenV8S said:
It is a continuous flow system. The pump runs continually (while the engine is running) and feeds full flow to the engine at all times. The excess fuel is returned to the tank via a mechanical pressure regulator (variable restrictor) which controls the pressure in the fuel rail.

On the V8 cars the fuel pump is controlled by the ECU via a relay, there are also a couple of fuses, an inertial cutout and the alarm/immobiliser in the circuit. A fault in any of these would prevent the pump from working.

As a quick sanity check I suggest you take a direct fused 12V supply from the battery to the +ve terminal on the fuel pump. If the pump runs you know there is an electrical problem which can be tracked down easily enough. It's also good enough to start the engine and get you home like this, if you're stuck. Just remember to disconnect the pump after you park!

If the pump still doesn't run, either the earth is bad or the fuel pump is dead.



That system sounds good on a car fitted with a fuel rail and electical pulse injectors but the S1 has the clockwork 2.8 motor and the long fuel injection pipe, Jetronic system.
The pump did not continualy run before but primed to pressure and then stopped.
Perhaps a capri forum may help?

Thanks anyway

GreenV8S

30,999 posts

308 months

Saturday 12th March 2005
quotequote all
My mistake, I'm not familiar with the clockwork stuff and assumed they were basically similar.

Don't you have a fuel rail return with a fuel pressure regulator on it then?

old64er

Original Poster:

1,388 posts

262 months

Saturday 12th March 2005
quotequote all
GreenV8S said:
My mistake, I'm not familiar with the clockwork stuff and assumed they were basically similar.

Don't you have a fuel rail return with a fuel pressure regulator on it then?


After some investigation today, the fuel pump relay was full of water!
The relief valve is located in the fuel distribution housing (an early type of fuel rail)and the pump works all the time on a feed and return system.

you live and learn, now if i can find out why the griff has lost power to the fuel pump, coil and starter i would be laughing.

GreenV8S

30,999 posts

308 months

Saturday 12th March 2005
quotequote all
You're having a run of bad luck aren't you? I would check the multiplug between the ignition switch and the main loom, otherwise perhaps an immobiliser problem?

Glad you got the S sorted anyway.

old64er

Original Poster:

1,388 posts

262 months

Sunday 13th March 2005
quotequote all
GreenV8S said:
You're having a run of bad luck aren't you? I would check the multiplug between the ignition switch and the main loom, otherwise perhaps an immobiliser problem?

Glad you got the S sorted anyway.


The griff has been like that for a while due to the ongoing S problem but at least if i can get the bonnet on today i can have some roof down fun and hopefully put the S for sale, should just about buy me a 5.5ltr short engine for the griff.

Thanks for the advice

GreenV8S

30,999 posts

308 months

Sunday 13th March 2005
quotequote all
old64er said:
should just about buy me a 5.5ltr short engine for the griff.

they do sound very tasty don't they?

mrufcs1

81 posts

259 months

Monday 14th March 2005
quotequote all
The pump gets it's feed from the 'pink'relay on the fuse box. It basically senses the engine firing and so cuts off the pump if the engine stalls (safety feature that designed to stop you spraying high pressure fuel around your car when you've just wrapped it around a tree !). All the fords fitted with the 'clockwork' injection system of the era have them fitted. I would have a good look at the connections around the relay, I've had shed loads of issues with corroded terminals around the fuse box. I have also owned 2.8 capris and siera's, these relays have a chequered history !