no pump poweer

[jasonochs25]

Guys/gals I've gone through pages and pages using search and cant find a fix, I need help ASAP. 97 4runner started but dies instantly. everyone I've talked to said fuel pump. I checked the COR and EFI relays and both check good and even swapped both with tail relay. I cut a hole in my floor and replaced the pump yesterday....still wont start. I'm not getting power to the pump. What can I check to figure this out? Please help. I have got to get this running before work.

 

[IBallEngineer]

Guys/gals I've gone through pages and pages using search and cant find a fix, I need help ASAP. 97 4runner started but dies instantly. everyone I've talked to said fuel pump. I checked the COR and EFI relays and both check good and even swapped both with tail relay. I cut a hole in my floor and replaced the pump yesterday....still wont start. I'm not getting power to the pump. What can I check to figure this out? Please help. I have got to get this running before work.

If it starts and dies, it is NOT the fuel pump. And probably not anything supplying power to the fuel pump, but rather a control issue. Ie the ECU or related circuits/components. But just to be sure...

Check the 20A EFI fuse and the 10A Ign fuse with a test light or multimeter. I won't go in to too much detail on checking power AND ground at teh COR and EFI relays because I don't have the 97 EWD and I know it is probably a little different than the one I have. Lucky for you my man El DURKO keeps good records. What say you [MENTION=10169]TheDurk[/MENTION] ?

:second:

 

[theesotericone]

If it starts and dies, it is NOT the fuel pump.

I agree it's not a pump issue. If the MAF got unplugged or has damaged wires it will do exactly what the OP is describing. As far as I have seen the ECU in these rigs is pretty bomber. I'd check the MAF wires first if it was my rig.

 

[jasonochs25]

I checked fuses, but will double check. My manual says fuel pressure, so thats why I went that direction. I'll check the maf wiring and other wires. I have 241k miles on it and its been the most reliable truck ever

Thank you for the replies. Keep them coming!!!

 

[jasonochs25]

but why no power to the pump when checked with volt meter?

 

[alumarine]

My understanding is that when cranking the motor the fuel pump gets power to start the motor.

Once the motor is running another circuit determines that it's running and powers the pump. If for some reason it can't determine the motor is running the pump will not get power.

The MAF is a component that determines if the motor is running.

I believe there is a procedure to make the pump run for testing purposes.

Have you checked for codes?

 

[jasonochs25]

no codes. that i know of. I dont have a obdII tester. There was no check engine light. It ran fine the day before. I checked all fuses again and checked the MAF and its wires. All seem good.

 

[TheDurk]

If it starts and dies, it is NOT the fuel pump. And probably not anything supplying power to the fuel pump, but rather a control issue. Ie the ECU or related circuits/components. But just to be sure...

Check the 20A EFI fuse and the 10A Ign fuse with a test light or multimeter. I won't go in to too much detail on checking power AND ground at teh COR and EFI relays because I don't have the 97 EWD and I know it is probably a little different than the one I have. Lucky for you my man El DURKO keeps good records. What say you [MENTION=10169]TheDurk[/MENTION] ?

:second:

This is for the '97 V6. Post up if OP has a 4 cyl.

Red Sox/Yankees series finale tonight so I don't have time to look at this....

 

[jasonochs25]

3.4l

 

[jasonochs25]

and honestly, I have no clue how to read the diagrams. or troubleshoot components. My manual is pretty much crap as far as that stuff as well.

 

[jasonochs25]

And maybe I should re-iterate my issue...It cranks, but as soon as it fires, it dies. It never completely starts if that makes sense. It fires and then immediately dies.

My original post states that it dies immediately after starting but I should have said it never completely starts.
My manual says...
1.loose or damaged wire harness connection at dist., coil, alternator,
2. insufficient fuel flow to injectors (which led me and several others to think fuel pump, including several youtube videos),
3. vacuum leak (I sprayed around engine vacuum lines with carb cleaner while the neighbor kid cranked it....nothing)
4. idle speed incorrect

 

[jasonochs25]

so I rented a code reader while I was at autozone getting my battery charged....See what I did there? The guy at autozone didnt realize it either.....

 

[KingPrat]

There was another post like this the other day. Can't remember if it was 3rd or 5th gen forum, and the negative battery terminal was loose.

Are you saying that your problem has been solved with a battery charge??

 

[jasonochs25]

no, im saying i disconnected the battery so I couldnt pull codes.

 

[TheDurk]

no, im saying i disconnected the battery so I couldnt pull codes.

That's funny.

Plus the codes won't be there when you put the battery back in. You have wiped the memory. You'll have to drive it until they come back, if there are any.