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ChriSOL

fuel pump not getting power

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after a week of poring over the EWD, bugging Rue, Kyle, and Mark my car is still not running.

 

driving to work and the fuel pump cut out. doesn't come on with ignition in the "ON" position anymore. it's a Walbro 255 and runs very loud as long as the key is turned to that mark. now it's dead quiet.

 

so far i've:

 

- verified no voltage at the connector in the trunk

- verified no voltage at the connector for the fuel pump resistor in the engine bay

- swapped fuel pump relay with a known working unit

- swapped circuit opening relay with a known working unit

- swapped EFI main relay with a known working unit

- jumped the EFI main relay in the engine bay fuse box and got voltage at pin 2 on the circuit opening relay

- still no voltage at the fuel pump relay pin 1, but i have 12v at pin 4 (indicated in EWD to be the wire running to pin 16 on the ECU).

 

i hotwired the pump to the battery and it kicks on so the issue is somewhere in the vicinity of the relay box, near as i can figure.

 

i've never done more wiring than installing gauges, stereo and fixing some minor issues so most of this is new to me. Rue and i found that the original circuit opening relay had been jumped with a piece of paper to be in constant on, but i'm not sure that was related.

 

tell me there's something stupid i've forgotten, or some easy troubleshooting tip that i missed. i've been checking all the grounds that i can find and haven't found anything wrong yet. i thought that i'd rubbed through one of my harnesses under the fenders but i relocated them years ago and nothing is messed up that i can find.

 

fp1_zpsffcc6e1t.jpg

 

fp2_zps6elj5zty.jpg

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manually ground the circuit op trigger from the ecu. At that point it should be key on. If it's not check out the ground on the circuit op.

 

Have you checked continuity from the circuit op to the pump plug at the trunk?

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nope, i need some longer leads to check continuity there.

 

so turn key to ON and ground the black pin from the opening relay, if the pump doesnt come on check the white/black wire to ground from the opening relay for a short?

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Chris, just a small note, have you followed the TSRM dignosis proceedure to the letter, and not shotgunned different ideas, like a blind man ?

You may be hunting the wrong problem.

 

First, get rid of ALL the bandaids on the car.

Then follow Toyota's proceedure.

 

I can't stress how important this is.

Do other wise is just fucking retarded.

 

I have fixed countless industrial machines/circuits, that people had been mis-diagnosing for years, by doing this.

Sometimes you couldn't see where the original circuit ended, and the 10 years of bandaids started, in which case it all got ripped out.

 

Stop being a 17 year old highschool autoshop drop out, and do it right.

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afaik there are no bandaids left in the wiring following the removal of the jumped circuit opening relay. when it comes to wiring i am that 17yo drop out gordo.

 

but going through the tsrm, ive already eliminated most of the items they're referring to either because my car doesnt have them post swap (afm, dist, cold start inj) or they checked out fine before i started getting into the wirinng (battery, alt, relays, grounds). the related systems like ign and the ecu getting power/triggering relays up the line is where i'm at now.

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Well, even a 17 year old can follow a TSRM, after all, Toyota wrote it for auto mechanics.......


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ps the jdm bumper and fenders i bought off you seem to work pretty great. they just need a roll and paint. i made the bumper support work and it clears my intercooler w/ no issues

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Yeah my attack would been like mark said, getting right at the COR and trying to get it running from there. If not, you're gonna have to confirm each leg of the circuit to do so, or be lazy and get some decent wire for the load side and run your own relay if you don't care or have time.

 

Use the power flow chart in the tsrm, or if it's kinda vague, create your own specifically about that circuit, then work it in steps confirming continuity from start to finish.

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If the tsrm is confusing, consult the section in front "how to use this manual". If that doesn't do it, kill yourself.

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tsrm isn't confusing at all, and for someone who admittedly never read a circuit diagram in his life the EWD is better than a textbook and this is a crash course. i'm still figuring out what conditions to recreate and look for with the meter. i guess i'd feel worse about it if it was something really dumb like a loose connector, but so far i haven't been so lucky.

 

i'm going to get back to the c/o relay tonight and try that.

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i kind of missed getting shit all over, so i'm glad i created an opportunity. feels like joining an AA group and admitting that you've never pissed the bed before.

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