Fuel Pump Failure
Discussion
After parking up in a hotel car park the Cerb now refuses to start
The engine turns over, and it has fired a couple of times
The problem appears to be the fuel pump because when the ignition is turned on usually I can hear it run strongly for a second or so priming the system
Now I can hear it run very weakly
I have tried swapping the relay, and even the fuse, with no effect
Because of how the car is parked it will be nearly impossible for me to remove the wheel and check the connections, and the weather won't help either
Any ideas or suggestions welcome
The engine turns over, and it has fired a couple of times
The problem appears to be the fuel pump because when the ignition is turned on usually I can hear it run strongly for a second or so priming the system
Now I can hear it run very weakly
I have tried swapping the relay, and even the fuse, with no effect
Because of how the car is parked it will be nearly impossible for me to remove the wheel and check the connections, and the weather won't help either
Any ideas or suggestions welcome
The last part in the supply to the fuel pump looks to be the inertia switch
Yellow is the supply into the inertia switch and Yellow/Black is the supply out of the inertia switch to the fuel pump
I suggest you apply a positive to the Yellow/Black at the inertia switch to see if it gets the pump running at full speed
There is a plug somewhere between the inertia switch and the pump (J52) that has the fuel pump supply and earth terminated to it (J52A and J52B)....You could try and find plug J52 then supply and earth the pump at it if the supplying of a positive at the inertia doesn't solve the problem
Other than the above you will have to gain access to the pump to properly test
See below diagram from here - http://www.thetvrsite.com/files/wiring-diagrams/re...
Yellow is the supply into the inertia switch and Yellow/Black is the supply out of the inertia switch to the fuel pump
I suggest you apply a positive to the Yellow/Black at the inertia switch to see if it gets the pump running at full speed
There is a plug somewhere between the inertia switch and the pump (J52) that has the fuel pump supply and earth terminated to it (J52A and J52B)....You could try and find plug J52 then supply and earth the pump at it if the supplying of a positive at the inertia doesn't solve the problem
Other than the above you will have to gain access to the pump to properly test
See below diagram from here - http://www.thetvrsite.com/files/wiring-diagrams/re...
Very relieved that the car fixed itself this morning, so I was able to get home
Had the car not started my plan had been just what you advised and try to find the J56 and check voltage on Yellow/Black, perhaps use my multimeter as an ammeter to run it directly
Failing that I was going to try to lift the car, as it wasn't actually raining, and check for jammed pump by reversing polarity, aided by jumping the PF relay (thankfully I had most of my tools with me as usual, including folding axle stands)
I am going to try to get to the bottom of this, and because the pump and wiring is extremely exposed to road spray I am going to start with replacing the connectors, and probably the pump as well
The car previously suffered from an intermittent problem that appears to be brought on by heat soak, where the engine would only rev to about 2k under load, although it would rev freely when out of gear
It would come and go as if a switch had be flicked, so I assumed it was an ECU issue, but perhaps the pump could be the culprit?
Had the car not started my plan had been just what you advised and try to find the J56 and check voltage on Yellow/Black, perhaps use my multimeter as an ammeter to run it directly
Failing that I was going to try to lift the car, as it wasn't actually raining, and check for jammed pump by reversing polarity, aided by jumping the PF relay (thankfully I had most of my tools with me as usual, including folding axle stands)
I am going to try to get to the bottom of this, and because the pump and wiring is extremely exposed to road spray I am going to start with replacing the connectors, and probably the pump as well
The car previously suffered from an intermittent problem that appears to be brought on by heat soak, where the engine would only rev to about 2k under load, although it would rev freely when out of gear
It would come and go as if a switch had be flicked, so I assumed it was an ECU issue, but perhaps the pump could be the culprit?
If you are going to replace the pump and connectors you could also run the pump wiring to an external relay rather than use the one fitted in the fusebox that contains all those horrible internal links, doing it this way the circuit would only be using the ECU signal to switch the fuel pump relay and the rest of the circuit would be your purpose built circuit with no joints here, there and everywhere
That sounds awfully like your imobiliser is failing. Exactly the same symptoms I had. If it happens again you can disconnect the battery, wait 5 mins and reconnect but be aware this would trigger my alarm for 10 secs. I had it do it in a petrol station, at work, and worse, in the outside lane of the M4 at rush hour, no fuel pump, no fuel, no engine running and a desperate attempt with hazards on to get to the hard shoulder.
Got recovered home and the bloody thing started to drive it off the truck, Got the immobiliser replaced a few days later.
Got recovered home and the bloody thing started to drive it off the truck, Got the immobiliser replaced a few days later.
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