No power to fuel pump

Hi guys, I have a 97 2Runner 5VZ I've been trying to get running as a daily commuter. I initially bought it for parts, for my 4Runner, but the GF needs a car now.

Right now, I'm at the infamous crank no start.

'Cracked open the fuel line in the engine bay and it's bone dry. There is fuel in the tank.

I tested for voltage at the blue-orange cable on the fuel pump connector, while cranking, and got nothing. Also unplugged what I believe is the COR, and tested for voltage at the blue-orange there while cranking, and got nothing.

I'm kind of a noob, but I set my multimeter to ohms and put one probe on each of the camshaft position sensor pins, it read 1.147. This seemed a little low according to the manual I have for a 99, but I got 1.160 on my running 4Runner so I think I can rule that out.

Spraying starter fluid while cranking gets the engine rumbling a bit.

I read on another post here that with the diagnostic port in the engine bay I can jump the +B to Fp to test the pump and rule out some stuff, but my diagnostic port doesn't have a pin in the Fp slot.

I tried with two different computers.

Thanks for any help or suggestions, this seems electrical, maybe related to sensors, and I'm very nooby when it comes to that but I'm doing my best

No Fp pin


12V at +B


No voltage at fuel pump connector blue-orange


No voltage when cranking at COR blue-orange


What a beauty

 

Not really versed in the fuel system, but can you use your working 4runner as a baseline? You should be able to use it to test suspect components and establish normal behavior since you know it runs fine. I don't think the 1 year age difference or the fact it's not a 4wd affects the system your trouble shooting.

 

Any codes from the OBD?

 

You should also be aware that a lot of vehicles have a 'G' switch inline with the wiring to the fuel pump. The purpose of the 'G' switch is to turn off power to the in tank fuel pump in the event of a high enough impact at the front of the vehicle. You said you bought the truck for parts, do you know the history of the vehicle?

I don't have access to wire diagrams - but you might need it. It would show if there was a switch (the switch is resettable, usually in the back of the vehicle).

There are a few really good electricians that hang out on this forum, such as @ElectroBoy and some others.

 

I was always told there is no inertia switch (what you call a g switch) on these rigs.

You need the wiring diagram. What I would do, is run 12v directly to the fuel pump and see if it runs. Then I would see if the car would start. That rules out a bunch. You then need to figure out why you aren't seeing 12v when the ignition switch is used.

 

Thank you for the information.

 

There isn't an inertia switch on 3rd gen 4runner

 

Awesome. Thanks for straightening me out.

 

These trucks have a different setup than a "G Switch". They have what's called a Circuit Opening Relay. It cuts power to the fuel pump in the event the engine stops running. Keeps the fuel pump from pumping fuel from a broken line in case of an accident. I'm not an automotive electronics engineer (I'm an aircraft electronics engineer, Navy trained), but from what I can tell, the COR is a darn good thing to have. Prevents fire during a accident, saving the driver, and first responders.

If you notice, in the test jack in the engine compartment, there is a B+ and a Fp jacks. If you jumper them, a paperclip works great for that, the fuel pump should run. Bypasses the COR, among other things. You can even start the truck with that jumper in, but it's a very BAD idea to run the truck on the road with the jumper in. If there's an accident, the safety feature that is the COR and it's associated circuits, won't shut the fuel pump off, so there's a possibility of fuel being pumped out onto the ground. Highly dangerous. It's a good way to test the operation of the fuel pump, like running a direct 12vdc wire to the pump, however.

In previous generations of the 4Runner, the COR is easy to find. In the passenger's side kick panel, right above the ECU. Very easy to locate, remove, clean, check, etc. It's something you might want to check on. I'm not certain about the gen 3 trucks, but I believe it's the same setup.

I hope my rambling helps some...
Pat☺

 

Pat,
Thank you for that. I knew there was a safety in the fuel system to prevent the fuel pump from fueling a bonfire in the event of an impact.

 

And now you know everything about it, whether you wanted to or not
Have fun
Pat☺

 

Appreciate you Sir, and thank you for your service.

 

Oh my, I didn't realise there was so much activity on this. thanks for all the input. I'll address some questions / comments:
1) Unfortunately while I am ok with mechanical things, I am a total noob at electronics. My 98 Runner doesn't really give me any hints. I did swap it's crank / cam position sensors between the two cars ( my running runner still starts, and the non runner still doesn't ).

2) I haven't been able to use a code scanner on it yet. I had rented one from an AutoZone quite a while ago, and it read nothing at all. I also had a Bluetooth OBD that would read live data from my 98 but nothing from the 97. I returned it. I'll rent another from AutoZone tomorrow just in case.

3) As far as the COR is concerned, I removed it and tested for voltage at the blue orange which seems to be the fuel pump power line and got nothing, I'm accumulating as many wiring diagrams as I can but have a hard time reading them xD.

4) I was going to try and hook up my 20v drill battery to the fuel pump ( assuming it being 20 volt doesn't cause an issue ). I'm guessing for this I would do negative to the white-blue and positive to the blue-orange on the fuel pump itself?


5) I'd like do use the diagnostic port / test jack to jump the fuel pump on but mine doesn't have any pin on the Fp slot. I've seen others mention this in various posts so I think 3rd gens might just not have it. A paperclip would have been a great way to test this , looks like jumping the pump with a battery is the only route here though.

 

For god's sake don't put 20v to the pump. Less voltage is ok, but 20, sure it might not hurt it immediately but it is really not advised.

 

Please do not put 20 volts to a twelve volt system. Bad things could happen - burn out the fuel pump, and the coil in the relays could burn out also.

 

Also, just buy a code scanner. Cheap ones that will read and reset codes are $30 on Amazon.

 

Haha ok, that's why I asked. Thanks! Can I just use the a car battery with some cables then? and did the photo of the plugs I showed as + and - look right?

 

Assuming I used the right pins. I jumped the pump and heard absolutely nothing. Maybe crickets in the background. Nothing came out of the fuel line I have opened in the engine bay.

I guess it's time to go find a replacement.

 

Dropped fuel tank. Supplied power to where the blue orange and white black plug in again and got nothing. Still trying to confirm those are the correct cables. Found some diagrams. Sorry for all the attachments. I know nothing about electronics so I'm trying to teach myself some stuff at the same time haha. The service manual is handy indeed.





Found this which showed pins 4 and 5 as being the ones I should supply power to. So the pump must definitely be bad...


control circuit


This one has the cable colors, black/white is ground and the "blue"/orange is power.


And this one showing the fuel pump connector "F10" so I can double-confirm that pins 4 and 5 were indeed the right ones.

 

Holy cow, any ideas what happened to this poor thing? lol I guess I should be getting a new pump assembly instead of just the pump...







Fuel sample... why is it red?

 

I would get the whole assembly. It's like $100 I think...pump and sending unit not included though

 

Where'd you see that? looks like rockauto is all sold out on assemblys

 

I only buy from the Toyota dealer. It was for my 2002 and it was a few years ago when I rebuilt the fuel and EVAP system.

 

Back again!

I got two fuel pumps, one from a junkyard and one from a guy parting out his runner. I grabbed his tank as well.

Both pumps run when connected directly to the battery. And I tried with both computers I have.

Anyway just for funsies I plugged in the extra pump ( its a little bent I know ), tried cranking, and... nothing. So... it still doesn't get power. Any more ideas guys? thanks for putting up with me

 

Have you checked/replaced the COR?
Have you jumped the B+ to Fp pins in the DS1 test jack? Does it run when you do?

Remember that the fuel pump gets it's ground from the the body of the tank, so make sure the tank is well grounded to the frame or body before you presume the pump is bad. With the pump sitting out of the vehicle that way, it's not getting a ground from the frame or body metal.

Beware of running the pump for more than a few seconds outside the tank. Remember that the pump is cooled by the fuel it sits in. With no fuel surrounding it, it can overheat rapidly.

Ok, I'm done babbling now...
Pat☺

 

I'm at work right now but I'll touch a few things you said. I had no idea about the ground haha, I know the pump is good as I ran it connecting it directly to a battery. I'll just install the tank and pump and try again when I get home. My 4Runner doesn't have an Fp pin. I'm guessing 3rd gens might not because neither of mine has it. I swapped the COR with my running 4Runner and it still runs, so both COR's I have seem to be fine..

And thanks for the advice I'll be careful with the pump or running it too long outside of the tank. A side note relating to the overheating - is that why people used to say that running a tank to empty is bad?

 

Ok, it ended up being the COR. Somehow I came full circle back to the one that wasn't working even after testing the other two ( which I guess came from the engine bay). I swapped so much stuff I lost track of which one was the original one. Organisation is key. Anyway new fuel pump and new cor and lots of electrical lessons learned. Thanks again! Sadly its running rough, but that's a mystery and post for another day. I'm beat tonight XD.

 

The Fp pin is the other end of the row from the B+. Looking at the diagram on the lid, it's the left end of the row that has the B+ on the right end.

Jumper the two pins, best choice is, obviously, a wire with the size male connector on both ends that fits those females, but even a paper clip uncurled so you can stuff both ends into the connectors works fine. Turn the key to ON, or RUN if you prefer that label for it. You will be able to hear the fuel pump run. This is presuming the fuel tank is installed, and has a gallon or two of fuel in it.

An alternative method, that I use, is to turn the key to START, but do NOT press the clutch down, or press the Clutch Cancel switch. Again, you'll be able to hear the fuel pump run. Again, presuming the tank is installed, and has some gas in it.

The COR is a sneaky little bugger that is forgotten by many, but is the usual problem. Keep it in mind

Glad it running again! Now fix the running rough. That can be a real bear to chase down. Are you getting a CEL from it? The codes it gives on the OBDII reader can be a real help for trouble shooting. Anywho, I wish you all the best of luck! If there's anything I can do to help...

Pat☺

 

I did get an cheapie OBD scanner as negusm recommended, I haven't used it yet but it looks like it's going to come in handy. CEL came on after running it for about five minutes, but then was gone when I restarted it. So I'll try the same thing again after work tonight.

$70 FOXWELL NT301 OBD2 Scanner Live Data Professional Mechanic OBDII Diagnostic Code Reader Tool for Check Engine Light

https://www.amazon.com/dp/B00UJV3E12?ref=ppx_yo2ov_dt_b_product_details

Thanks again for the help. I'll be making a new post shortly if I can't figure this idle out haha