Currently having an issue where the engine will crank no problem but will not turn over or start. Here is the history of the issue:

2 weeks ago I noticed that it was having more laboured starts, it would take twice as much cranking to get the truck to fire up. Assuming the spark plugs were end of life, I replaced them. (I've already done the coils 35k miles ago). I started with no issue, and I ran it until warm then shut it down.

New day, went to start it, same laboured starting issue but ran no problem and after the truck was warm the issue didn't seem to persist.

Two days later, full crank but no start, and now thats where it is.

Here is everything I have checked:
- swapped the EFI relay to check for a failure
- Repeated everything with the spark plug install - no obvious problem signs on the new plugs
- Checked all the fuses in the engine and cab

NOTES:
- when the key is turned to ignition, I cannot hear the fuel pump start
- In park, with the key turned, the truck throw the code P0340
- Tried starting with starter fluid, with the plastic ducting off the intake manifold, tried to turn over and then shot white smoke out of the intake manifold... could be a timing / cam position issue?

Unsure if I should proceed by chasing the fuel pump as an issue or chase the Camshaft position sensor as an issue. Any guidance on where to do next would be super appreciated.

When I Google P0340 Toyota I get:

Code P0340 indicates there is a problem with the electrical wiring of the circuit attached to the camshaft position sensor. This issue can result in the display of a multitude of other codes that relate directly to your vehicle's camshaft. In addition, your powertrain control module (PCM) could also be damaged.

If it were me I would have it towed to a dealership or trusted local garage and get a good diagnosis. Then I would decide if it were something I could handle or not. If you have AAA you can get the tow there and back for free, probably. You'll owe the garage about an hour for diagnosis.

Others will chime in here and offer more/better advice, but that's what I would do. Good luck.

Two quick notes:

- The engine will not run without a sealed tube between the MAF sensor and the throttle body
- The fuel pump does not prime/run with the key in the "ON" position. It will only run while the key is in the START position or the engine is running.

If you are trying to do starting fluid, you need to pull the tube, spray, then reinstall the tube... Or spray it in a vent line or something like that.

In general, "turning over" is the term used for the starting moving the engine, not when the engine is running.

-Charlie

UPDATE:

Tried installing a new Cam position sensor, P0340 is cleared but it didn't affect the ignition at all. Still lots of cranking with no start.

UPDATE:

Tried chasing the problem to the top of the fuel pump array, sprayed contact cleaner but that didn't have any effect. Does anyone know of a good walk-through on how to test the fuel pump without pulling the tank. Vehicle is vry rusted and I am worried about snapping lines, etc.

In the search bar, just above the black bar at the top, type in "fuel pump pressure". You'll find numerous threads on how to test pressure, what the pressure is, etc.

UPDATE:

Things are a little weirder now and I am uncertain what I have done to solve it, but it seems like I am chasing an electrical issue. Here is what has happened.

Uncovered the wiring heading towards the fuel pump from the ECU. Disconnected and reconnected every contact point and sprayed with contact cleaner.

As per some other thread's advice, banged on the tank with a rubber hammer to bring the fuel pump back to life. She started! Now Bonnie is running seemingly without issue, except worth noting that I introduced a garage 120v starter/charger to the mix rather than a jumper pack and learned along the way that my battery jumper pack is toast.

Where some strangeness began - after getting it running, the following things randomly started working again:
- sensor for the rear hatch began reading as if it was stuck open and the overhead light stayed on (wasn't this was before)
- Light for over the licence plate on the tailgate stayed on (drained the battery again overnight and then after jumping it again it turned off)
- I swear my 4WD started working again, which has been an on/off issue for the past few months.

This leads me to wonder if I am chasing a ground/electrical wiring issue. I'm going to keep updating this thread in case anyone down the line has to chase a problem like this and wants to follow along.

Any advice on what these might be symptoms of would be greatly appreciated!

The first two strange issues could be bad wiring to the hatch (in the rubber boot where it bends when you open/close the hatch).

-Charlie

Just how low was your battery voltage when you were testing things/ wouldn’t start?


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Battery Voltage read 11.9 before cranking on the first test, but over a week of attempts really took it down until it hit 6v and I tried some battery jumper packs.

UPDATE: Laboured start first thing in the cold morning - seems I may be right where I was 2 weeks ago. Perhaps it is a fuel pump and I just have it a second life by banging on the tank?

11.9 volts is extremely low. Essentially, the battery is dead at that point. At 6 volts it's useless. I think this is the source of your electrical problems. You shouldn't even try to diagnose anything at that low voltage because automotive systems are designed to run at 12.x volts. If the engine will start, then the alternator should provide the necessary voltage of 12.7 - 13.1. If it doesn't then your alternator is not working. Do a voltage check at the battery when the engine is running.

Banging on anything won't solve any problem. It's a possible fix if you're stuck somewhere. For a daily vehicle it's not a fix. If you're not getting the correct pressure in the fuel line then your pump probably needs to be replaced. Other possibilities are clogged fuel line and corrosion. That's my 2¢