Mobile Fuel Pump Mechanic
Discussion
Within the 14CUX loom the ignition supply only supplies 2 points - one is the wire going to the FP relay that you have 0 volts on , the other is pin 19 on the ECU plug to turn the ECU on- So assuming there is no skull duggery by TVR or anyone else in the loom, you know you have 12v ignition on the ECU because RoverGauge is working.......
blitzracing said:
Within the 14CUX loom the ignition supply only supplies 2 points - one is the wire going to the FP relay that you have 0 volts on , the other is pin 19 on the ECU plug to turn the ECU on- So assuming there is no skull duggery by TVR or anyone else in the loom, you know you have 12v ignition on the ECU because RoverGauge is working.......
Which just leaves the the connection between the loopback and the fuel pump relay pin 86.Steve
It does now feel we are getting somewhere. I located the loopback and the 3xgreen/white, 1xblack wires. All connections are 12V+ with the RGauge set to continuous fuel pump, although it sounds like that should not make any difference to those wires. Sadly the pump did not prime while I was buried in the footwell peeling off ancient insulation tape.
Coefficient said:
It does now feel we are getting somewhere. I located the loopback and the 3xgreen/white, 1xblack wires. All connections are 12V+ with the RGauge set to continuous fuel pump, although it sounds like that should not make any difference to those wires. Sadly the pump did not prime while I was buried in the footwell peeling off ancient insulation tape.
One of those white/green wires goes to the fuel pump relay pin 86 so if you still don't have 12V at the relay then there has to be a break between the two.Steve
Coefficient said:
I couldn’t figure how to connect at the loop back. I did easily bridge from pin 30 to 86 though. That caused the relay to click with Rocergauge set. But still no fuel pump which is frustrating. Perhaps related to my messing with the fuel pump yuh terminals. About to give up now....
I was thinking just poke the wire into the back of the loopback.Anyway progress all the same. you know the relay is alive but have not proved its contacts inside are good. You have proved the ECU is alive and talking to the relay.
So take your wire and bridge fuel relay pin 30 to pin 87 (with the Black wire and possibly a white/purple wire) and see if the pump works.
Steve
Coefficient said:
I did the test without Rovergauge. Bridging to 87 didn’t help but I was surprised the bridge to 86 still clicked the relay?
Did you unset the immobiliser?Putting power to pin 87 still has to go through both the immobiliser and the inertia switch before it can run the pump.
Steve
Edited by Steve_D on Friday 3rd July 21:30
Good news is that the wire wiggling seems to have worked. The embarrassing news is that the last few tests the relay was in the wrong socket. The weird results made me go back to Steve's 2016 thread and I thought the picture looked a bit odd. I guess the long term solution is to properly re-wire from the loopback to the relay socket. Hopefully I can now get the car to a TVR specialist for this.
For more fun while the glove box is out though, I might try to replace the heater control valve motor. And if that works I may even try to get the blower fans working again....
Thanks to everyone for their guidance and encouragement!
For more fun while the glove box is out though, I might try to replace the heater control valve motor. And if that works I may even try to get the blower fans working again....
Thanks to everyone for their guidance and encouragement!
Well done!!
For reference, I have had a lot of problems over the years with my Chimaera heating system.
Symptoms - fan not running.
Diagnosis - replace, or repaired, the control box under the dash top three times - they are prone to the live terminal burning out.
First time I bypassed the terminal myself, second time I bought a spare off PH classifieds, third time I got Jodie at Python Racing to rebuild it - that one is still working.
Second fault was a wiring fault, under the carpet by the passenger's left knee. Fixed.
Then my fan itself seized. Replaced by Mat Smith, which he declared to be a horrible job, as it is located behind the fibreglass and carpet by the passenger's left lower leg. Horrible place to get at, and they don't make an exact replacement any more, so you need to butcher/cobble.
If it is a new fan that you need, check the heater matrix while you are at it. I believe it is located in the same place.
Mine was completely clogged with mud and rubbish off the roads.
After 41,000 miles of ownership, I now have warm air in the cabin when I want it.
For reference, I have had a lot of problems over the years with my Chimaera heating system.
Symptoms - fan not running.
Diagnosis - replace, or repaired, the control box under the dash top three times - they are prone to the live terminal burning out.
First time I bypassed the terminal myself, second time I bought a spare off PH classifieds, third time I got Jodie at Python Racing to rebuild it - that one is still working.
Second fault was a wiring fault, under the carpet by the passenger's left knee. Fixed.
Then my fan itself seized. Replaced by Mat Smith, which he declared to be a horrible job, as it is located behind the fibreglass and carpet by the passenger's left lower leg. Horrible place to get at, and they don't make an exact replacement any more, so you need to butcher/cobble.
If it is a new fan that you need, check the heater matrix while you are at it. I believe it is located in the same place.
Mine was completely clogged with mud and rubbish off the roads.
After 41,000 miles of ownership, I now have warm air in the cabin when I want it.
Gassing Station | Griffith | Top of Page | What's New | My Stuff