EFI problems, no combustion (1 Viewer)

[uscmas412]

This is interesting.

Has it sat for a while before this no start condition occurred?

Sort of. It sat for four months while I was deployed. Came home to a dead battery, replaced the battery with a new one and it cranked right up. Drove fine for two months after that.

 

[tacocat]

Then this started out of the blue one day? How much gas is in it right now?

 

[uscmas412]

Then this started out of the blue one day? How much gas is in it right now?

A little over half a tank. I’ve only filled with non-ethanol fuel due to the amount of time it sits, but this is a fresh tank.

 

[uscmas412]

I’ve had no start issues before, but it was always a Click, No start. As in ignition or starter issues.

 

[uscmas412]

UPDATE:

I removed the Fuel Pump Resistor and Fuel Pump Relay. The resistor appears to be original to the vehicle, but no visibly chaffed or broken connections. I cleaned all connections with electronic contact cleaner and checked for proper operation per the FSM multimeter tests. Both checked out okay.

For anyone else, this thread provided good information regarding the resistor test.

If the resistor does fail, I just discovered they are discontinued. Part # 23080-66010

I installed both back in the vehicle and I'll be damned if it didn't fire right up. After cleaning up the fuel spill from the FPR return hose and reconnecting it, it fired up again without hesitation. After cleaning up the backseat a bit, I tried to pull it in the garage.

It now cranks intermittently, but with serious hesitation and stumbling. It looks like I'm on the right track, but I need to get this perfect. I think I may have a bad connection going to the ECU. Any other ideas?

 

[azngarage]

check the fuel filter. it's under the intake manifold

 

[uscmas412]

check the fuel filter. it's under the intake manifold

Replaced last year with OEM Toyota.

 

[uscmas412]

Bump. She’s back to not starting/no combustion due to lack of fuel.

I think the problem is somewhere in the attached diagram. Where is the fuel pump switch/VAF meter located?

 

[uscmas412]

This problem is driving me nuts, I've checked everything in the diagram above and tried to start after checking each connection. Nothing. I pressed the gas pedal 10x with the key to ON and it fired right up. I let it run for 10 minutes, increased throttle to 4K RPMs and everything was running smoothly. Shut it off.

Now it won't start again.

 

[BILT4ME]

Bump. She’s back to not starting/no combustion due to lack of fuel.

I think the problem is somewhere in the attached diagram. Where is the fuel pump switch/VAF meter located? View attachment 2326708

What Manual are you looking at?

If you are working on a 97 FZJ80, it doesn't have a VAF. The VAF is on the 91-92 versions.(3FE)

 

[uscmas412]

What Manual are you looking at?

If you are working on a 97 FZJ80, it doesn't have a VAF. The VAF is on the 91-92 versions.(3FE)

I've got a 97 FSM, but I found that digram pic in another thread, so it very well could be from the 3FE. I tested the MAF per the FSM and it was good.

 

[jonheld]

What Manual are you looking at?

If you are working on a 97 FZJ80, it doesn't have a VAF. The VAF is on the 91-92 versions.(3FE)

That is not a 3FE manual.
3FE manuals all call it an AFM (air flow meter) and it does not have a separate fuel pump relay and fuel pump resistor like the 1FZ.

 

[BILT4ME]

That is not a 3FE manual.
3FE manuals all call it an AFM (air flow meter) and it does not have a separate fuel pump relay and fuel pump resistor like the 1FZ.

I always get them confused.

AFM 91-92
VAF 93-94
MAF 95-97

 

[uscmas412]

Still troubleshooting, starting to become intimately familiar with the EWD but it's still a learning process.

I'm operating off a few assumptions I need verified:

1. If the fusible links were bad, I would experience other electrical issues. Specifically, the FL MAIN 2.0L feeds to the headlamps and the 15A EFI circuit. If it was blown, the headlamps would not turn on. Also, I would not be getting good spark or the CEL with the key to ON. See attached diagram.
2. If the NSS/PNP switch was bad, the starter would not engage.
3. The VSV controls fuel pressure, but only under certain conditions (high-temps and immediately after starting). A faulty VSV wouldn't necessarily prevent the engine from cranking. The VSV does appear original to the vehicle. The VSV is one of the few items I haven't checked due to its location.
4. Is the fuel pressure regulator "downstream" from the injectors? I.e. fuel flows from the pump to the fuel filter, through the fuel rail and then to the FPR? If so, I don't believe it would cause this issue.
5. With the FPR return hose disconnected, no fuel was coming out at cranking and it was dry when disconnected. Lack of fuel is the root cause of my issue.

 

[jonheld]

Have you verified that the fuel pump logic is correct?
Does the FP run if you jump out the logic?

 

[uscmas412]

Have you verified that the fuel pump logic is correct?
Does the FP run if you jump out the logic?

I don’t believe the logic is correct. When I replaced the fuel pump, I tested the old one with a 9V battery and it kicked right on.

But both the circuit opening relay and fuel pump relay checked out good.

 

[azngarage]

Disconnect the connector at the fuel pump. Have someone crank the car and see if you see a 12v on the Red and Green stripe wires (it's the biggest wire and should be the top right if you look at the connector). If you used the volt meter, positive lead on the red/green wires and negative lead to the chassis ground.

 

[jonheld]

I don’t believe the logic is correct. When I replaced the fuel pump, I tested the old one with a 9V battery and it kicked right on.

But both the circuit opening relay and fuel pump relay checked out good.

So you have not verified the logic.

 

[uscmas412]

Okay just tried the following steps:

1. Sprayed starter fluid in intake. Cranked, stumbled and died immediately
2. Hooked up 12V to the new fuel pump (still installed in the tank) per the FSM, it immediately turned on.
   1. Left the fuel pump harness disconnected, tried cranking since the fuel lines were pressurized. Cranked, stumbled, died.
3. Placed the multimeter positive lead on the R/G wire and black lead to body ground as described by @azngarage. Had my helper crank and measured 11.4V
   1. Plugged the harness back together, tried cranking and nothing. Same issue.

What does this tell me? Does this verify the logic @jonheld ?

 

[azngarage]

Check the connector of the fuel pump