92 Camry - no power to fuel pump

toyota
electrical-wiring
camry

#1

1992 Toyota Camry, 4 cyl 2.2 5-speed trans. (5SFE engine)

A year and a half ago i was driving down the road and got a phone call. I pulled over to answer the phone and put the car in neutral while on the phone and back in to first when i was done. I went to pull away and the car stalled out. Tried to start the car again but the engine would not run. Called a family friend that knows cars and was suggested the fuel pump was bad. Purchased a new pump and installed it roadside with no change. Towed the car home and checked all my fuses, everything was good. changed a few relays, the EFI main relay in the engine bay, the Fuel pump relay (?) as it was called at Autozone (located behind the glove box in the center next to the starter relay) all with no success. Tried to bridge the pump at the test terminal under the hood (FP to B+) but did not get fuel pressure. Hot wired the fuel pump off the battery and the pump kicked on and pressurized. I am at a loss as to what to try next. I dont have power at the block connector on top of the pump, and when testing the pins in the relay behind the glove box got voltage but only when cranking the engine. someone help me… I would love to get this car on the road again, it was a blast to drive and super reliable up until this strange issue… I have a mechanic telling me that it is probably the computer, and im prepared to go to my local pick and pull to snag one tomorrow if this sounds accurate. Thanks in advance to everyone for reading =)


#2

Is there an accident fuel cutoff switch?


#3

my local auto parts store was able to pull one up for the vehicle, but i cannot for the life of me find where on the car it is, and was told that they were mainly a ford thing? this was strange to me but i cant figure out where to install the thing if i buy it


#4

The fuel pump won’t get powered up unless/until the computer senses the engine is turning. There’s probably a sensor in the distributor that tells the ecm when the dist shaft is turning, and that sensor may be faulty. Could be a problem w/the distributor itself. You could remove the distributor and see if it turns or not during cranking. You may also have a broken timing belt, if your engine uses a belt rather than timing chain.

It should be relatively easy for a Toyota experienced shop to determine why the pump isn’t being powered.

I have a 92 Corolla and I wouldn’t have any difficulty figuring that out. Fixing whatever’s not working, that may be difficult. But figuring out, not so much.

BTW, on my Corolla the fuel pump gets power during cranking whether the engine is turning or not.


#5

google this 92 camry fuel shut off switch location


#6

I was helping out a friend of mine with his Toyota Sienna, and that thing had a circuit which powered the fuel pump only in next cases:

  1. engine is cranking
  2. oil pressure sensor detects non-zero oil pressure

if you tell that circuit is getting energized only during the crank, I would check if oil pressure sensor is not at fault or its wire is not chewed by a rodent for example

oh… and I hope you’ve already checked the fuses :slight_smile:


#7

Google search doesnt seem to yield anything for me, but re mentioned the “it being a ford thing”. another forum directed the person to the EFI main relay, but i have changed that already


#8

Yep as far i can tell i have even changed all the relays involved with the problem, ill go double check the rodent thing tomorrow but with it dying on the road so randomly i dont think that was the original issue. Is the computer POSSIBLY the issue? with the options i have tried at this point im almost ready to go pull one out of a salvage just to see, but i am getting mixed reviews on that being worth the time or not. some say yes, some say the computers go out so rarely that it is probably not the issue. Ill swap the oil pressure switch tomorrow and post results as well


#9

Try this.

Locate the fuel pump relay and unplug it.

In the relay socket, install a jumper wire in the terminals for the secondary side of the relay.

If the fuel pump runs anytime the ignition is turned on, the driver in the computer for the fuel pump has failed.

Tester


#10

when you say fuel pump relay are you talking about the one behind the glove box?


#11

I don’t know where the fuel pump relay is on your Camry, but on my corolla it is located in the center console area, sort of between the gear shift lever and the dashboard. Toyota doesn’t call it a fuel pump relay. they call it a “circuit opening relay”. Located adjacent to the ecm.


#12

ok thats the one behind the glove box on my car. we tested voltage there in the sockets, on various different pins and only seemed to get power when cranking, but that power is not getting to the pump


#13

behind glovebox it seems to be a relay opening the circuit when car is not supposed to get any fuel

it may be another one, in a fuse box: http://www.shilas.online/watch/-W409vrHE24/

this link may be of some help too: https://ww2-secure.justanswer.com/uploads/djenn434/2011-01-21_183732_pump_0000.jpg


#14

the fuse box in the car is just standard fuses, all checked and working. Under the hood there are 2 fuse boxes, one of them has nothing to do with the fuel pumo, they are labeled as fan fuses/relays… the other one has a few thing that are important to this issue… the first is labeled the EFI MAIN relay, this has been replaced. there is another green block fuse in there that i cant at the moment remember but that has also been replaced. also, i believe the vid you linked is on a gen newer camry than mine


#15

I have posted another link from '94 Camry, and it looks like it is one relay only, and it activates of the starter or by ECU which is supposed to pull a second relay coil to the ground

based on this, oil pressure switch has nothing to do with fuel pump on this camry, so the theory of ECU failure which @tester provided may be quite possible, given it is not a trivial wires/connectors fault

having wiring diagram it should be possible to test wires, just to make sure you are not swapping parts to find the trouble was in wire


#16

The circuit opening (fuel pump) relay has two control coils. From what I see the power to the 1st relay coil goes through a 10 amp fuse called “starter” and apparently is powered up w/the key in “start” . The second control relay is controlled by ECM pin FC (presumably fuel control). The power to the pump comes off pin 1 of the relay, which is also connected to FP on the diagnostic connector. The power input to the relay comes in on pin 2, originating from the battery via a 15A fuse then the EFI main relay.

If you connect FP on the diagnostic connector to battery +12, the fuel pump should spin. Does it?


#17

im assuming thats the terminal under the hood, with all the female sockets. I jumped FP to B+ and the pump did not run.


#18

With FP jumped to BAT, do you measure 12 volts on pin 1 of the fuel pump relay?


#19

i didnt test voltage with it bridged, just tried to start it with no success… should i check voltage? what would be my next step based off the possible results?


#20

With FP jumped to BAT, follow that circuit to pin 1 of the fuel pump relay, then to the fuel pump. The wire is labled l/b which I presume means yellow with brown stripe. It’s that same color all the way to the fuel pump. At some point you’ll lose the 12 volts, and you need to determine why.