Bob Posted November 27, 2006 Share Posted November 27, 2006 Tried firing the car up for the first time in 2 months last night (battery fully charged, cranked for 30 seconds without EFI fuses, etc.) but she wouldn't turn over. I then realised that the fuel pump wasn't pressurising the system at all, which it certainly needs to do as I've just changed the fuel filter. I've checked the engine bay fuses, and just checked the continuity/operation of both the EFI main relays and they're all fine, I even checked voltages going to the fuel pump (across the 2 large wires): Ignition on: 0V Engine cranking: 8.6V I've also checked daft things like the gear-box is in Park. I odn't think it's the pump itself as the pump is obviously trying to do something when it's being fed the voltage at cranking (can feel the vibrations from it through the top of the plastic hanger assembly). Has anyone experienced something similar or can shed any light on this? Could it be the Fuel pump ECU? This is the final obstacle before I can run my engine for the first time in months! Quote Link to comment Share on other sites More sharing options...
dandan Posted November 27, 2006 Share Posted November 27, 2006 I do not know about the Supra fuel pump ecu in particular (hopefully someone will) but some ecu's will only give the fuel pump a short pulse of power at ign on. This may be 0.5-2 seconds long - ie the pump will not run continuously with the ign on. If you had a leak then this short pulse wouldn't pressurize the full system at all - are you definitely leak free (harder to tell with no pressue!). Have you tried flicking the ign on and off maybe 3 or 4 times with about 2 seconds between each try - then try starting it? Might help with the diagnosis? Or even get someone else to look at the voltmeter at the fuel pump when you first turn the key to ign on.... Quote Link to comment Share on other sites More sharing options...
SimonB Posted November 27, 2006 Share Posted November 27, 2006 It only runs the fuel pump when cranking, not just with the ignition on, that's normal. It should only take a couple of seconds to reach normal fuel perssure from unpressurised. If you want to check the pump is running, join up the FP and +B terminals on the diagnostics port under the bonnet (by the dipstick) and turn the ignition on - that will run the pump continuously. EDIT - to say that it also runs the pump briefly after you key off I believe, but not with the ignition on. Quote Link to comment Share on other sites More sharing options...
Ric Posted November 27, 2006 Share Posted November 27, 2006 8.6V is that not a little low? although i dont know much about the fueling side of things that is about all i could think of. Quote Link to comment Share on other sites More sharing options...
SimonB Posted November 27, 2006 Share Posted November 27, 2006 8.6V is that not a little low? although i dont know much about the fueling side of things that is about all i could think of. No, that's about right. The ECU runs it at low voltage when at low revs/boost and then switches to 12v when needed. Quote Link to comment Share on other sites More sharing options...
JohnA Posted November 27, 2006 Share Posted November 27, 2006 Hence the '12V mod' where the punters second-guess Toyota and feed full voltage to the pump even on idle/low load, overwhelming the fuel return (and heating up the fuel for no good reason) Quote Link to comment Share on other sites More sharing options...
Ric Posted November 27, 2006 Share Posted November 27, 2006 as i said dont know much about that side of things Quote Link to comment Share on other sites More sharing options...
flukey-lukey Posted November 27, 2006 Share Posted November 27, 2006 My fuel pump ECU decided to die not long ago, so I did the 12v mod. Not too sure if this is a good or bad thing to do, but it worked Quote Link to comment Share on other sites More sharing options...
Bob Posted November 27, 2006 Author Share Posted November 27, 2006 thanks for the comments, guys. I have tested the fuel pump as mentioned and found that it works fine - there's pressure in the line, the return is fine and there are no leaks. However, after trying to start it another couple of times, there was a smell of petrol from the exhaust so I took out the EFI fuses and cranked it over a few more times just to clear as much as possible out of there. So, it would seem that there is no spark Can anyone advise on how to test the igniter pack? Quote Link to comment Share on other sites More sharing options...
alan_blue Posted November 28, 2006 Share Posted November 28, 2006 take them out and lay them on their side and crank over looking for the spark Quote Link to comment Share on other sites More sharing options...
Ian C Posted November 28, 2006 Share Posted November 28, 2006 That's the coil pack test my dear chap Igniter pack = substitution. Are you getting a fault code errrr 14? -Ian Quote Link to comment Share on other sites More sharing options...
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