Discussion
Hi guys
The fuel pump on the 400 will not stop.
Turn the ignition on and the pump runs ,but instead of slowing and stopping it keep going full chat.
It will not stop until the ignition is turned off.
It has been like this since I bought it.
So any ideas or has it just been bodged?
Many thanks.
Neil
The fuel pump on the 400 will not stop.
Turn the ignition on and the pump runs ,but instead of slowing and stopping it keep going full chat.
It will not stop until the ignition is turned off.
It has been like this since I bought it.
So any ideas or has it just been bodged?
Many thanks.
Neil
An injection pump will run and run by design, if powered.
The fuel goes up to the engine and returns via the fuel pressure regulator and return pipe.
It's not like one for carbs that shuts off by itself at a preset pressure.
Usually it will only start when cranking but some have it wired to feed continually, which is a tad dangerous, if the engine stops you want the pump to stop too.
The fuel goes up to the engine and returns via the fuel pressure regulator and return pipe.
It's not like one for carbs that shuts off by itself at a preset pressure.
Usually it will only start when cranking but some have it wired to feed continually, which is a tad dangerous, if the engine stops you want the pump to stop too.
Pulling the Pektron should stop it
Pulling the injection relay should stop it
Disconnecting the Air Flow Meter should stop it
Pulling the fuel pump relay should stop it
Pulling fuse 10 should stop it
Pulling fuse 7 should stop it and if it doesn't there should be another fuse fitted into the circuit that does stop it, supply to the fuse pump must be fused
Does pulling the fuel pump relay or fuse 7 stop your cars pump running?
If yes, the problem is before the fuse (dash area) and not between the fused output and the pump
The below diagram might be of some help
Pulling the injection relay should stop it
Disconnecting the Air Flow Meter should stop it
Pulling the fuel pump relay should stop it
Pulling fuse 10 should stop it
Pulling fuse 7 should stop it and if it doesn't there should be another fuse fitted into the circuit that does stop it, supply to the fuse pump must be fused
Does pulling the fuel pump relay or fuse 7 stop your cars pump running?
If yes, the problem is before the fuse (dash area) and not between the fused output and the pump
The below diagram might be of some help
Edited by Penelope Stopit on Saturday 19th September 20:28
Hi Penelope, hope you're keeping safe. I've tried disconnecting the AFM, the injection relay and the pektron, and the bugger still runs......
Someone has tried hard to bodge it in the past. I cant see where the bodge wiring is though. I have had the whole dash out and had a good tidy up of the relay board but nothing appeared to be out of the ordinary. The original pump wiring however has been cut off as it appears to be been damaged when they fitted the roll bar back in 2000 so the pump has a new wire to it but it's fibre glassed into the body, again where the roll bar penetrates the original body shell. I cant see where the feed comes from. I might have to take the interior out again to try and trace it.
Someone has tried hard to bodge it in the past. I cant see where the bodge wiring is though. I have had the whole dash out and had a good tidy up of the relay board but nothing appeared to be out of the ordinary. The original pump wiring however has been cut off as it appears to be been damaged when they fitted the roll bar back in 2000 so the pump has a new wire to it but it's fibre glassed into the body, again where the roll bar penetrates the original body shell. I cant see where the feed comes from. I might have to take the interior out again to try and trace it.
KKson said:
Hi Penelope, hope you're keeping safe. I've tried disconnecting the AFM, the injection relay and the pektron, and the bugger still runs......
Someone has tried hard to bodge it in the past. I cant see where the bodge wiring is though. I have had the whole dash out and had a good tidy up of the relay board but nothing appeared to be out of the ordinary. The original pump wiring however has been cut off as it appears to be been damaged when they fitted the roll bar back in 2000 so the pump has a new wire to it but it's fibre glassed into the body, again where the roll bar penetrates the original body shell. I cant see where the feed comes from. I might have to take the interior out again to try and trace it.
Hello KKsonSomeone has tried hard to bodge it in the past. I cant see where the bodge wiring is though. I have had the whole dash out and had a good tidy up of the relay board but nothing appeared to be out of the ordinary. The original pump wiring however has been cut off as it appears to be been damaged when they fitted the roll bar back in 2000 so the pump has a new wire to it but it's fibre glassed into the body, again where the roll bar penetrates the original body shell. I cant see where the feed comes from. I might have to take the interior out again to try and trace it.
Thank you, yes, kept safe up to now, only 2 visits to the beach this year, do the shopping masked up and that's just about it, rest of the time is spent at home, 6 months of it and counting
Hope all is well in your neck of the woods, keep safe
The fault's a good one
Should have mentioned in the earlier post
Pulling the fuel pump relay should stop it
Pulling fuse 10 should stop it
Pulling fuse 7 should stop it and if it doesn't there should be another fuse fitted into the circuit that does stop it, supply to the fuse pump must be fused
Does pulling the fuel pump relay or fuse 7 stop your cars pump running?
If yes, the problem is before the fuse (dash area) and not between the fused output and the pump
Can't think of any reason why TVR would alter the wiring for the fuel pump to constantly run with ignition on and them leave the Pektron relay fitted even though it would have been made redundant.
No way, they wouldn't have been able to market the car with a constantly running pump, safety and all that
Anyway, there is no primer circuit, the pump runs when cranking and is then run via the AFM contact once the engine is sucking enough air to swing the flap
Had better edit the earlier post
Was messing about with this for a couple of hours.
The only way of shutting off the pump was pulling fuse 7.
Nothing else apart from turning the ignition off would stop it.
Not exactly clued up on car electrics so when this chaos is over someone with lots more knoledge can have a look.
N
The only way of shutting off the pump was pulling fuse 7.
Nothing else apart from turning the ignition off would stop it.
Not exactly clued up on car electrics so when this chaos is over someone with lots more knoledge can have a look.
N
Slightly related, this is what I happens when coolant gets down the wiring into a relay.
[quote=lancepar]
Thanks all, I'm confident things are back to normal.
I replaced the 4pin 30amp relay for a new one.
Thought the buzzing could have been the stepper motor. But decided to clean the plug connections anyway.
Moment of truth starting sequence.
Immobiliser red led extinguished with fob plug, no buzzing, no pump run, turn key to 1st position, pump runs, turn key engine starts.
Turn off engine with key, pump stops, and short delay red led starts flashing.
Replaced relay not getting warm.
Can now finish putting the carpet back round the fuel tank and put everything from the dash I removed.
Cheers
Update.
Photo of replaced relay, the tiny water leak must have migrated down the wires into it.
[quote=lancepar]
Thanks all, I'm confident things are back to normal.
I replaced the 4pin 30amp relay for a new one.
Thought the buzzing could have been the stepper motor. But decided to clean the plug connections anyway.
Moment of truth starting sequence.
Immobiliser red led extinguished with fob plug, no buzzing, no pump run, turn key to 1st position, pump runs, turn key engine starts.
Turn off engine with key, pump stops, and short delay red led starts flashing.
Replaced relay not getting warm.
Can now finish putting the carpet back round the fuel tank and put everything from the dash I removed.
Cheers
Update.
Photo of replaced relay, the tiny water leak must have migrated down the wires into it.
lancepar said:
Slightly related, this is what I happens when coolant gets down the wiring into a relay.
Thanks all, I'm confident things are back to normal.
I replaced the 4pin 30amp relay for a new one.
Thought the buzzing could have been the stepper motor. But decided to clean the plug connections anyway.
Moment of truth starting sequence.
Immobiliser red led extinguished with fob plug, no buzzing, no pump run, turn key to 1st position, pump runs, turn key engine starts.
Turn off engine with key, pump stops, and short delay red led starts flashing.
Replaced relay not getting warm.
Can now finish putting the carpet back round the fuel tank and put everything from the dash I removed.
Cheers
Update.
Photo of replaced relay, the tiny water leak must have migrated down the wires into it.
Nice
That relay should be put on display in a glass box
lancepar said:
Thanks all, I'm confident things are back to normal.
I replaced the 4pin 30amp relay for a new one.
Thought the buzzing could have been the stepper motor. But decided to clean the plug connections anyway.
Moment of truth starting sequence.
Immobiliser red led extinguished with fob plug, no buzzing, no pump run, turn key to 1st position, pump runs, turn key engine starts.
Turn off engine with key, pump stops, and short delay red led starts flashing.
Replaced relay not getting warm.
Can now finish putting the carpet back round the fuel tank and put everything from the dash I removed.
Cheers
Update.
Photo of replaced relay, the tiny water leak must have migrated down the wires into it.
That relay should be put on display in a glass box
Neil E 99 said:
Was messing about with this for a couple of hours.
The only way of shutting off the pump was pulling fuse 7.
Nothing else apart from turning the ignition off would stop it.
Not exactly clued up on car electrics so when this chaos is over someone with lots more knoledge can have a look.
N
In which case fuse 7 has an ignition supply connected to itThe only way of shutting off the pump was pulling fuse 7.
Nothing else apart from turning the ignition off would stop it.
Not exactly clued up on car electrics so when this chaos is over someone with lots more knoledge can have a look.
N
No it shouldn't
As shown in the above diagram, fuse 7 is supplied by the fuel pump relay
At least you now have proven what's causing the problem and are able to pass your findings onto whoever will be delving deeper into the fault for you
The thing is, if you fancy checking further, the modification of the fuse wiring may be there to be seen when looking at the back of the fuse-box
As shown in the above diagram, fuse 7 is supplied by the fuel pump relay
At least you now have proven what's causing the problem and are able to pass your findings onto whoever will be delving deeper into the fault for you
The thing is, if you fancy checking further, the modification of the fuse wiring may be there to be seen when looking at the back of the fuse-box
Thanks Penelope.
Finally had half hour to myself to have a look.
Working from the owners handbook so I assume the fuse board is not upside down!! Fuses at the bottom.
From what I can see the White and Purple goes into the Headlamp control relay. However if everything is arse about face then yes its the fuel pump relay
2 yellow wires straight out of fuse 7. The diagram shows a Yellow with a Yellow and Red
All I can say is, there are many after-thought connections with shrinkwrap a plenty!
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