help fuel pump / relays / wiring
Discussion
fuel pump doesnt kick in, well its does every now and again, I have checked the relays and they seem to be working. The wiring going into the relay socket seems to be ok but I think this is the problem as if I put the relay back in nothing then by chance put everything in the footwell the pump starts again etc etc, has any one taken one of the relay sockets apart before.
any other suggestions welcome as I am meant to be going to a meet tomorrow and this is the second one Iam looking like missing as every time we have a meet the car breaks down.......spooky
cheers
adi
any other suggestions welcome as I am meant to be going to a meet tomorrow and this is the second one Iam looking like missing as every time we have a meet the car breaks down.......spooky
cheers
adi
someone else on here has had this,cant remember who though.the connector contacts can become worn,giving a loose hold on the relay terminals.have a closer look and see if you can bend them a little to tighten.failing that you could always replace the blocks with some crimp terminals for an immediate effective repair until you buy some new blocks.i think thats what id do.
Had the very same thing happen to me. I found that one of the spade sockets within a multiplug had been fitted wrong way round. These spades have a spring clip on them which locks them into the multiplug. With this one being the wrong way round, its spring clip was not able to retain it and it worked its way out slowly. First thing I knew was when it was just loose enough to start going intermittently open circuit.
Look on the bottom of the relay plug to see if one of the connections is not fully inserted. If it's OK then disconnect the ECU multiplug, remove the rubber seal which will reveal the securing screws, unscrew these and pull the rear casing off the plug. I found one of the spade sockets in there was the wrong way round and was causing my fuel pump to work only intermittently.
Don't just push it back in. You've go to make sure it's the right way round otherwise it'll just work its way out again.
>> Edited by tvrbob on Saturday 12th February 17:38
Look on the bottom of the relay plug to see if one of the connections is not fully inserted. If it's OK then disconnect the ECU multiplug, remove the rubber seal which will reveal the securing screws, unscrew these and pull the rear casing off the plug. I found one of the spade sockets in there was the wrong way round and was causing my fuel pump to work only intermittently.
Don't just push it back in. You've go to make sure it's the right way round otherwise it'll just work its way out again.
>> Edited by tvrbob on Saturday 12th February 17:38
Yes. Had several unrelated wiring faults that took me several months of investigation to track down.
The relays themselves have an intermittant failure mode, they can run fine for 20 minutes and then stop until they've had ten minutes to cool down. A poor contact between the socket and the relay can cause local heating which knackers both the relay and the socket. The poor contact could be caused by corrosion or by the terminal being too loose. If it's too loose you can feel this by putting an ordinary male spade terminal into the terminal. If it goes in easily the terminal is probably too loose. Both problems can be cured by cleaning up the contact faces and lightly squashing the terminal to increase the clamping load. If you've had this problem bear in mind that it might have overheated any relay you fitted, so even if a new relay didn't cure the problem, it may have been damaged and contributing to future problems.
The next potential problem area is the inertia cut-off that is supposed to cut power to the fuel pump after a collision. On mine this is a 'tilt' switch screwed to the front of the passenger's footwell. I don't know where this is on yours, but some Chimaeras have them in the boot. Mine was badly corroded and would intermittantly go open circuit.
Finally check the condition of the wiring by the pump. It's exposed to the elements and vulnerable to corrosion. Mine had a partially broken wire which probably wasn't helping reliability.
If you're having trouble, I suggest that as a precaution you make up a direct power supply for the pump. It just needs the right size spade connector for the pump, a fuse, and something that you can connect to a known good 12v supply. On the V8S the battery is conveniently in the boot so I used a croc clip at this end. At least then you know you can always get home.
It's probably going to be a bit of a job to track it down but rest assured you will eventually get to the bottom of it.
>> Edited by GreenV8S on Saturday 12th February 17:46
The relays themselves have an intermittant failure mode, they can run fine for 20 minutes and then stop until they've had ten minutes to cool down. A poor contact between the socket and the relay can cause local heating which knackers both the relay and the socket. The poor contact could be caused by corrosion or by the terminal being too loose. If it's too loose you can feel this by putting an ordinary male spade terminal into the terminal. If it goes in easily the terminal is probably too loose. Both problems can be cured by cleaning up the contact faces and lightly squashing the terminal to increase the clamping load. If you've had this problem bear in mind that it might have overheated any relay you fitted, so even if a new relay didn't cure the problem, it may have been damaged and contributing to future problems.
The next potential problem area is the inertia cut-off that is supposed to cut power to the fuel pump after a collision. On mine this is a 'tilt' switch screwed to the front of the passenger's footwell. I don't know where this is on yours, but some Chimaeras have them in the boot. Mine was badly corroded and would intermittantly go open circuit.
Finally check the condition of the wiring by the pump. It's exposed to the elements and vulnerable to corrosion. Mine had a partially broken wire which probably wasn't helping reliability.
If you're having trouble, I suggest that as a precaution you make up a direct power supply for the pump. It just needs the right size spade connector for the pump, a fuse, and something that you can connect to a known good 12v supply. On the V8S the battery is conveniently in the boot so I used a croc clip at this end. At least then you know you can always get home.
It's probably going to be a bit of a job to track it down but rest assured you will eventually get to the bottom of it.
>> Edited by GreenV8S on Saturday 12th February 17:46
shes alive, they always say dads are the best well in this case I have to offer the greatest respect to my father who came up tonight, ran a check across the relays one by one using a battery charger, found that the fuel pump one was faulty, we went out to try and get a replacement couldnt so came home and he took the relay apart, its really coroded inside, put cleaned it all put it back together and hey presto she lives again.
Must order 2 new relays and get a spare, judging by the state of that onne the other I assume will need a change
good ol' dad
thanbks for the help guys
adi
Must order 2 new relays and get a spare, judging by the state of that onne the other I assume will need a change
good ol' dad
thanbks for the help guys
adi
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