Cliffnotes: Pump runs with key in "on" position when the AFM door is opened or the test connection is jumpered, but when key is turned to start it does not run. What is causing this?

Ok, so I just finished putting in my rebuild, get all excited to fire it up.

I turn the key to "on", and I don't hear the fuel pump prime. So, I'm thinking maybe it's a different car of mine where you hear the pump prime first, since it's been so long since I've driven the rex.

Turn the key, nice strong exhaust pulses, but not even an attempt at firing.

So, I figure out there's no pressure in the lines. Do a little research, try jumpering the connection with the key to "on", the pump runs. Try opening the AFM door with the key to on, the pump runs.

So, since that's working, what is causing it to not run at start, or what is it I should check?

 

The safety switch in the AFM has failed. This is what shuts off the fuel pump if the engine stalls (like in a crash). Jumpering the the test connector bypasses the safety switch for testing purposes. You need to repair the switch or replace the AFM. In the mean time you can drive the car with the jumper wire in place with no problems, but I wouldn't leave it like that.

 

******So, I figure out there's no pressure in the lines. Do a little research, try jumpering the connection with the key to "on", the pump runs. Try opening the AFM door with the key to on, the pump runs.***********

I don't understand the NZ answer since you wrote the above. You just said you put the key to ON and opened the vane and the pump ran, like it should. And you did the jumper job with the key to ON and the pump ran like it should.

So? What makes you think it's not running when you go to START?

Try this. Reach under the car and pull the small wire off the starter. Now turn the key to START. The motor won't turn over, that's a given, but you should be able to hear the pump run as you hold the key to START.

If it does not, then you have a open wire in the starter circuit to the Circuit Opening Relay. I run without that particular wire/circuit and have no starting issues. The vane pulls open when the the starter is turned over due to the suction on the vane from the rotors.

 

Whoops, brain fade. I completely missed the bit about pushing open the flap...

 

That's understandable, coming from someone that uses the metric system. If you came from a land that used fractions, feet and miles your brain wouldn't fade as much. because it would get exercised more .....humor, I'll stop this right here.

 

Thanks for the replies guys. I tested with the small wire off the starter and I did hear the pump kick on, so something else is causing my no-start situation :S

 

Pull the fuel pumps plug off.

Buy a can of starter fluid.

Spray for just one to two seconds into the air filter or snorkel to the air filter. No more.

Try starting the engine. Does it make a starting sound? Rev for a moment? Remember, fuel pump plug off when you do that and do NOT try to keep the engine running with starter fluid if it does rev up. If it revs up and dies do that procedure again then reconnect the fuel pumps plug and try yet again, this time it might keep running.

If with starter fluid it NEVER revs up, then I'd suggest its a spark issue.