help! -no power at fuel pump

when the ign key is put into position 2 I am seeing no voltage at the pump,so it does not prime .

checked the all fuses inc EFI ones,tested the relays which are working fine.

I have quite a lot of sensors on the inlet manifold and throttle body unplugged,inc the injectors,but would this make any difference?

the car is in the middle of having its single conversion so the engine can not be cranked yet to test.

anybody have any ideas why I have no power at the pump?any help would be much appreciated.

thanks Rich:)

Start with the easy one - are you de-immobilising the car before testing?

Next step - with the ignition off, jumper pins +B and FP in the diagnostic port. Turn the ignition to position 2 and de-immobilise the car and see if the fuel system fires up. (don't put in or take out the jumper wire with the electrics on as it sparks like a bastard, not good when you are checking the fuel system...)

-Ian

Start with the easy one - are you de-immobilising the car before testing?

 

Next step - with the ignition off, jumper pins +B and FP in the diagnostic port. Turn the ignition to position 2 and de-immobilise the car and see if the fuel system fires up. (don't put in or take out the jumper wire with the electrics on as it sparks like a bastard, not good when you are checking the fuel system...)

 

-Ian

hi Ian,the car is being de-immobilised every time,will try putting the jumper in the 2 ports tommorrow and report back,thanks for the help.

Rich:rolleyes:

if I get no action from the fuel system with the jumper in between the terminals ,what comes next?

The fuel pump on the Supra doesn't run until you are cranking the engine, so it won't run with the ignition on unless you jumper the diagnostics port as Ian says.

Actually when you key off it spins the pump for a couple of seconds to preprime the fuel system for the next starting event, I think it does this regardless of if the engine has been turned over or not.

-Ian

Yeah, but if you're turning the key to position 2 from off and then going to have a look at the fuel pump voltage and expecting it to be on it won't be, that's what I'm getting at.

Yeah, but if you're turning the key to position 2 from off and then going to have a look at the fuel pump voltage and expecting it to be on it won't be, that's what I'm getting at.

there is 2 of us on the job,1 person with a multimeter at the back of car and 1 at the ign key.

OK Richie, the diagnostic port jumper trick has proven out the fuel pumps but it bypasses the fuel pump ECU, the EFI no2 Relay, and the EFI No2 fuse.

I still say that you should finish the engine work before getting worried over this The fuel pump ECU has a control line from the main ECU, and as you say there are meny sensors unplugged etc so the main ECU is probably fault coding left right and centre and not letting anything run. Cross this bridge if you get to it

-Ian