1998 Toyota 4Runner no fuel

Tiny
JARRODVASQUEZ
  • MEMBER
  • 1998 TOYOTA 4RUNNER
I have a 1998 Toyota 4-runner with 150k auto trans. When it was running it would surge at speed and want to die at idle. I have replaced fuel pump twice, fuel filter, fuel pressure regulator o2 sensor and finally tried another ecu. I have narrowed my problem now I think to no voltage at the fuel pump. I have checked both relays the EFI relay and the COR under the dash and both are good. I check voltage at EFI relay and get 12v at COR I only have approx. 2volts. As I read the schematic the only thing between the the two relays is the ECU so what would make the ECU draw voltage? Some sensor or what sorry if I rambled but this one is confusing to me thank you for your help
Tuesday, August 21st, 2007 AT 1:41 PM

6 Replies

Tiny
2CARPRO JACK
  • MECHANIC
  • 11,533 POSTS
Does it not start now? Or does it still die at idle and surge? Now im confused too. Have you check the fuel pressure with gauge?
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Wednesday, August 22nd, 2007 AT 7:35 AM
Tiny
JARRODVASQUEZ
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  • 4 POSTS
The truck no longer runs because of lack of fuel. Not enough voltage to make fuel pump run. No guage nessesery because fuel pump not getting adequate voltage to run and pressurize system.
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Wednesday, August 22nd, 2007 AT 9:38 AM
Tiny
2CARPRO JACK
  • MECHANIC
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My schemaytic (2.7l) only shows a junction block between the COR and EFI relays. What wire is only getting 2 volts? The blue/orange comes from the COR through the junction then to the fuel pump. White/blue should be the 12 volt feed from the EFI relay to the COR
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Wednesday, August 22nd, 2007 AT 11:39 AM
Tiny
JARRODVASQUEZ
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The white blue wire from the EFI module is only getting around 2 volts so I think there is a draw from somewhere but where if it was a break or short there would be no voltage. One more thing I forgot to state that is a V6 4runner hope this helps!
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Wednesday, August 22nd, 2007 AT 7:06 PM
Tiny
2CARPRO JACK
  • MECHANIC
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If the blue/white wire only has 2 volts, yet the EFI relay is getting 12 volts in, I would try a new EFI relay, might not be getting a good connection inside, it is the source of the power for the COR, MAF, supplies voltage to the ECM. If you suspect there is a draw/short, try unplugging the MAF and see if the voltage changes, same with the PCM
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Thursday, August 23rd, 2007 AT 7:50 AM
Tiny
JARRODVASQUEZ
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Put everything back together and have discovered a problem in my troubleshooting, well it turns out that I am getting twelve volts to the fuel pump when I crank the motor but when I release the key lose all voltage to fuel pump. Totally lost on what would cause this problem. Thanks anything that you could give me would really help thanks in advance.
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Thursday, August 30th, 2007 AT 9:57 PM

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