Fuel pump not turning on

[defuse411]

Im not sure what is going on but I have tired the folowing

-Fuel ECU Bypass = nothing
-diagnostic port bypass = nothing
-efi relay replaced = nothing
-direct 12v = turns on

I am now tempted to just wire in a 87a relay and be done with it all but would prefer to find the actual problem.......any ideas?

I have went over most of the info in Alldata but it is kind of lame but kind of at a dead end

Thanks
E

 

[PR_SC400]

Disconnect the fuel pump, get a multimeter and see if it gets power at the pump if not then trace it back till you find the problem it could be something as simple as a bad wire.

 

[smokeyo1]

Totally agree, clearly a bad wire But where?? why not run a new wire from the ECU trigger to your own 87a relay, jump on the feeds and kick it into life, remember though by doing that the pump gets constant 12v and doesnt drop down to 9 when running (wont hurt)

 

[samsdad]

Now does the fuel pump actually work?

Are you sure that it hasn't died?

 

[samsdad]

Oh hang on read post a bit better...

Fuel pump relay is triggered by earth return from ECU so possible ECU fault

 

[John M]

When you say direct 12v does work, where are you applying it?

 

[defuse411]

update

Just a little backround I bought this car not running from a close friend I know a little history since he has owned it but thats all.....


-I found out there was a fault in the signal wire to the EFI relay from the ECU so it wasnt turning on

-I wired in a relay where the Fuel ECU is in the rear, increase gauge size on the wire so the Pump is now working with the key


now now since I have the pump able to turn on off the key it seems I dont have injector pulse( checked with noid light) or spark..... Im going to keep digging any info would be nice, I am following the 6 page wire diagram of the car going wire by wire

 

[defuse411]

just tested for voltage at the coils and good there

 

[gloverman]

Have you ever had the vehicle running?

 

[John M]

For most vehicles a lack of injector pulse and spark means the ECU doesn't see the engine turning.

Before you tackle that, have you pulled the ECU itself and checked it for leaking capacitors? I'd hate for you to address all the symptoms but miss the main cause.

 

[PR_SC400]

^ bingo!

Or just get another ecu from the salvage yard cheap I bought a 98 vvti ecu for $15 the other day.