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I have a RAV4 that I've been trying to get running for a while now. Here's what's working:

  • Spark based on simple light tester
  • Installed coil packs from a known working engine and new plugs
  • Compression is within spec on all cylinders
  • Fuel pressure at the input to the fuel regulator is within specification
  • Swapped fuel pressure regulator on the fuel rail from a working vehicle and noticed the fuel rail was pretty dry
  • Cleaned injectors, tested for clicking with 12V, cleaned fuel rail
  • Turned over engine with pressure regulator detached from fuel rail and saw fuel flowing
  • Turned over engine with injectors pointed up and saw fuel spitting lightly in a sequence that looked reasonable for each cylinder
  • Vehicle won't fire, sprayed starting fluid into intake and it sputters alive once, but then will not sputter again.

I'm going to remove the throttle body and clean it up and look for anything there but I'm pretty stuck. What could I be missing here? The history on the vehicle is mostly unknown. Previous owner said it ran fine then one day she couldn't get it to start and it's been sitting for a long while now.

UPDATE:

  • There's no engine codes and I had a friend check with TechStream for any additional codes and it's ok
  • I've tested the pressure going into the regulator on the fuel rail and it was within spec.
  • I pulled the fuel regulator off and swapped it with a working one off another RAV4 (same year and running fine).
  • Previously I was getting RPM readings over ODBII while cranking but I'm going to swap out the cam shaft sensor
  • When i had the fuel regulator off I cranked it and saw fuel pour out, but not spray (it is a much bigger diameter than the injector nozzle so I think it was ok)
  • Injector nozzles when pointed up sort of spurted rather than a full blast spray that I sometimes see on injector test beds on youtube
  • Today I swapped out injectors with a known working car and no change
  • Tried a cam sensor from another running vehicle with no change

Here are some data screen shots from before and during a few attempts at cranking the engine.

https://i.stack.imgur.com/AmZkN.jpg

I retested with a fuel pressure gauge and found that even though the new fuel pump was putting out fuel, it was very low pressure < 5psi. Putting a known good pump in for the new one supplied enough pressure to get the car running again. There's still problems, but I'm at least able to drive it and it runs again.

Thanks to everyone who helped give ideas.

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  • Engine speed should always register when cranking. You need to confirm your crank sensor signal. You say the fuel pressure is in spec but what numbers are you hitting at the rail while cranking? You also need to confirm injector and coil operation. Also in 2/3 of your pictures the fuel pump relay is off when cranking. If you need to, reduce the number of pids so you get faster updates.
    – Ben
    Apr 4, 2019 at 23:04
  • Thanks Ben. I'm trying to retest the fuel pressure right now and having difficulty repeating what I got before (about 34 psi). Perhaps there is a problem in the crank sensor harness. Is there another way to look for the crank signals?
    – user6972
    Apr 4, 2019 at 23:23
  • You might be able to use a multimeter set to ac rms. You'd be looking for around 2v IIRC. You could also do a resistance test, spec is 985Ω - 1600Ω. If it shows in spec but you don't get an AC reading then there may be a spacing issue or the tone wheel is damaged. 34psi sounds low spec is something like 45-50psi. Make sure you're getting the full 12+ volts and have a good ground to the fuel pump.
    – Ben
    Apr 4, 2019 at 23:30
  • Well, i got it running, sort of. The new fuel pump was faulty. It was putting out fuel but the pressure was <5 psi for some reason. I put an older pump back on it and I was able to get it to fire up finally. Thanks
    – user6972
    Apr 5, 2019 at 22:19
  • 1
    Occam's Razon still in full effect, 7 centuries later. Air, fuel, and spark. Glad you got it running.
    – SteveRacer
    Apr 6, 2019 at 1:30

1 Answer 1

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I suspect one of two things:

Ignition timing, possibly a failed crank or camshaft position sensor.

The "sudden" failure of the previous owner suggests this.

There are two terminals in the diagnostic connector (OBD II) that you can short to establish base timing. You might try that and see if it makes a difference.

Also, are there any engine codes? Those would probably reveal a failed position sensor.

The other (more likely) possibility is a failing fuel pump or clogged fuel filter. You can replace the fuel filter cheap enough, and it probably needs one anyway. Then check fuel pressure with a gauge. Fuel "spitting lightly" isn't a good sign (although I didn't witness it). Fuel should be spraying out in a fine mist. If it's just spitting drops, fuel pressure isn't right - back to the pump and/or filter. And you mentioned the rail seemed dry. Try cranking for a bit and then opening the rail somewhere; there is probably a test port you can use. Fuel should still be under substantial pressure and will come squirting out. (Wear safety glasses.)

That also might explain why it sputters on ether. Starting fluid vaporizes quite easily and might support combustion. Little spits or drops of injected fuel (due to low pressure) will not. High pressures are needed for proper atomization and achieving a uniform A/F mixture density.

If you brought it to me, I'd start with a new fuel filter, and then check fuel pressure. Bad pressure means failed fuel pump.

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  • Thanks. I updated my post with more information. I'll try the crank shaft sensor, but I've put in a new fuel pump and prefilter on the pump, but I don't think the 2002 RAV4 has an additional filter.
    – user6972
    Apr 3, 2019 at 22:52
  • Check the pids with an OBD II scanner while cranking. Take a look at intake air and coolant temp sensors, as well as any airflow sensors to see if they make sense.
    – SteveRacer
    Apr 4, 2019 at 4:10
  • I added some screen shots from my neighbor's friend's computer while it was cranking. There's no error codes and the sensors seem ok to me. Engine speed will register if I use a bit of starting fluid. Note there was 4 misfires recorded on cylinder 1 but during start I think error codes are suppressed.
    – user6972
    Apr 4, 2019 at 21:56

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