Soggybite3
Member
But when i put current to the relay points the pump works and she still only stars but dies. Glowplugs not working off key but it could be a relay.
Datatek
Well-Known Member
As above, it's not an immobiliser issue as that would prevent it firing at all.
Soggybite3
Member
I get that. I have 12 v at feed to relay but not out. What would cause this
Datatek
Well-Known Member
Fuel pump on the diesel only runs under certain conditions which vary according to year.
When you say you have 12 volts to the relay, is that to the coil or one side of the contacts. I take it you are talking about the fuel pump relay?
Soggybite3
Member
Fuel pump relay yes. one contact has power but not the other. if i bridge the 2 i get fuel but she still dies after starting. So why no power out to pump, Could it be the inertia switch which i have pressed but could it be faulty
Datatek
Well-Known Member
What year is your car? On early cars the pump only runs whist cranking or when the engine is running.
The glow plug relay?
One side will be powered when needed and the other maybe a live feed to the plugs that is connected from within the relay. You can check a relay with a 12v battery and a DVM. Power the relay to switch and check continuity on the other two connectors.
A relay can work but the connecting surface that makes the circuit can burn inside of it. Everytime the contacts inside the relay open a small particle of the surface is pulled away and eventually leaves a damaged contact surface.
Do you have another relay you can try?
Have you checked to see if there is current at a glow plug?
Datatek
Well-Known Member
I think he was talking about the fuel pump relay?The glow plug relay?
One side will be powered when needed and the other maybe a live feed to the plugs that is connected from within the relay. You can check a relay with a 12v battery and a DVM. Power the relay to switch and check continuity on the other two connectors.
A relay can work but the connecting surface that makes the circuit can burn inside of it. Everytime the contacts inside the relay open a small particle of the surface is pulled away and eventually leaves a damaged contact surface.
Do you have another relay you can try?
Have you checked to see if there is current at a glow plug?
Thanks Keith, I'm confused
Datatek
Well-Known Member
Have another beerThanks Keith, I'm confused
Soggybite3
Member
Fuel pump relay yes sorry your beer goggles tricked you. My P38 is a 1999 model diesel manual
Don't think it runs when cranking on early cars. That was brought in to try and help with the hot-start issue. It runs before cranking if the engine is cold.
Soggybite3
Member
Yeah it kicks in until pressure to fip then turns off until start then kicks on again when running i believe
Soggybite3
Member
Sorrry it is the relay for the electric fuel pump. I also have a glow plug issue which has been wired direct to battery for test purpose but will be removing the inlet on the weekend to access fip and glowplugs. I believe the relay for that is in the box behind the battery. not sure which one or if there is only 1 cant remember but will be checking. My real question has been that why do i only have power into pump relay and not out. I will be checking the inertia switch as well. Beyond that i am puzzledThe glow plug relay?
One side will be powered when needed and the other maybe a live feed to the plugs that is connected from within the relay. You can check a relay with a 12v battery and a DVM. Power the relay to switch and check continuity on the other two connectors.
A relay can work but the connecting surface that makes the circuit can burn inside of it. Everytime the contacts inside the relay open a small particle of the surface is pulled away and eventually leaves a damaged contact surface.
Do you have another relay you can try?
Have you checked to see if there is current at a glow plug?
RangeRoller dt
Well-Sprung Member
Even with a dead lift pump the FIP should be able to pull enough through for tickover. Keeping above 1/2 tank helps in this situation.
Do you have diagnostics to check cps sensor?
Do you have diagnostics to check cps sensor?
Don't apologise matey, have you tried another relay in it is place to rule it out?
There is a large plug under the fuse box that you could check for corrosion. I'm not sure what comes and goes through the plug but a check over couldn't harm.
The fusebox is removed quite easily with its coloured plugs.
Soggybite3
Member
yeah i could try. Trying another relay wont work as the power to the pins/socket is the issue.
Datatek
Well-Known Member
The is no "kick in kick out" there are either 2 or 3 circuits that can energise the pump.
Soggybite3
Member
Care to explain in more detail
