2005 AC won't start - fuel system problem?

I have a 2005 AC. It's been parked up a mountain for a few months while I was distracted with other things.

Symptoms:
- Won't start. Battery is good, engine cranks, no start.
- Gas tank shows empty even though it has fuel in it (and I added more to be sure).
- P0441 - EVAP System incorrect purge flow
- P0452 - Evaporative Emission Control System Pressure Sensor / Switch Low Input
- P0455 - Evaporative Emission Control System Leak Detected (Gross Leak)

I'll bet $100 that the underlying issue is that mice chewed wires .... I've had that problem once before. If it matters, it's also parked on a bit of a slope, front end uphill.

Bluedriver suggests replacing the vapor canister purge solenoid and vapor canister purge valve assembly. But what about the fuel tank showing empty?

I'm 2 miles up a steep gravel road and a long way from a tow truck. Any suggestions on wiring to examine or parts to try replacing? Diagrams to help me find my way?

Thanks.

 

Why bother with what Bluedriver says? They're having you treat the codes, but that won't help you get the truck starting, it'll just help with emissions and possibly smooth idling, eh?

I think you probably pinpointed your problem: Mice. But don't just suspect chewed wires, they like to chew the plastic lines coming off the fuel tank, under the bed and cab also, it's not just the wires.

No fuel signal = likely chew-through of the sender wire. If you have a way to check for fuel pressure while cranking that would be helpful.


Here's a good video on fuel diagnostics:

https://www.youtube.com/watch?v=VoerlgT8pck​

Another great video on starting diagnostics, maybe not as applicable:

https://www.youtube.com/watch?v=0jWouSQYTnU​

 

Oooh, here's the example I was looking for.

While I suspect a rodent probably did chew through the wire, I just wanted to share another target of rodents with our 1st gen trucks. Check this thread: https://www.tundras.com/threads/fuel-assembly-line-leak-replacement-02-sr5-4-7l.14153/

 

Thank you. I will take a look this weekend and report back.

 

AAA+ might be helpful to have. 4 tows/year up to 100 miles max anywhere.

 

@drapp this document may also help with regards to how the fuel system works. But it doesn't cover chewed wires, unless rodents also chewed up your crankshaft position sensor wiring. Given the gas needle stopped working, it makes more sense that they chewed something on/around the pump, or between the cab and pump.

 

Well. It’s good-news bad-news.

good news: not a complicated diagnosis.
Bad news: the mice chewed A LOT down there.

photo attached, looking in on top of the gas tank from the drivers side.

Am I right to think that I have to drop the tank to get at the damaged wiring and sort it out? If so I think that’s going to be beyond me.

Thanks again for your advice and help.

 

Whoops. Looks like they got a vent line as well. See this photo. Ugh.

i think I’m looking into a tow truck at this point.

 

Or maybe lifting up the bed would give me enough room to work on it? Less work than dropping the tank?

 

It's pretty easy to drop the tank...especially if you don't have to be careful of the wires

 

DO NOT REMOVE THE BED.

It's a waste of time on access cab, the fuel tank port is under the cab, not the bed. Not to mention, there area lot more bolts and wires to removing the bed, than dropping the tank.

It's not hard. I had to do it last winter, in the snow, which sucked because of the snow, but was not difficult until I broke a bolt. If the bolts that hold the tank straps are not seized, its a simple job, even by yourself, with a helper, it would be MUCH easier.

The trick is, to make sure the bolts turn, before you drop the tank. Its easy to knock out the strap pins with the bolts tight and drop the tank, but to put it back in, you have to be able to unscrew those bolts because they are what tensions the straps and hold the tank in.

 

Start hitting any related bolts now with PB Blaster, Kroil, your your preferred similar penetrating oil.

Dropping the tank is probably easiest. Complete the wiring work, and replacing any needed parts. then wrap the bejesus out of it with something that rodents won't eat, or will kill them if they do.

This has to be the worst I've seen yet Good thing they hit the tank sender wire, else the diagnosis wouldn't have been so easy

 

Thanks guys for all the advice and help. Following up:

I think the 05-06 Tundras must have a different tank design than the earlier first gens. I was able to unbolt the bed and lift it up a couple of feet and get to the fuel pump and all the chewed wiring. I was more confident lifting the bed than dropping the tank.

I bought a new plug to connect to the fuel pump because I didn't know what to expect of the wires. There were a total of 7-8 chewed wires. I spliced them all with crimps -- you can see the wiring complete in the attached photo.

Taped the wires and got them into a loom and the truck fired right up, runs fine, no codes. So far so good!

I still have a problem with the fuel vent system. They chewed up the vent tube that runs up to the filler neck, as well as the attachment point to the tank (the red plastic). I tried attaching rubber tubing, you can see in the photo, which works great except that when I filled the tank, some gas dribbled out of the attachment point. Need to figure that out next.

But: the truck runs, it's down the mountain. Thanks again!

ps - need a plan for the mice. another day ...

 

Indeed. My fuel tank port is about 6" under the rear of my cab and bolts in instead of that lock ring looking arrangement.

 

Glad you got it running! Good diag, and thanks for following up, we love to see the wins when they happen. Many don't bother. You just saved a LOT of money by looking up under there.

 

Is the red part removable?

Worst case scenario you can drill and epoxy in a barb fitting (or drill and tap a npt barb) after dropping the tank to clean any shavings out.

 

I wouldn't be surprised if there's already shavings in the tank from the rodents. But then again, that's what OEM screens on fuel tank uptakes are for.

Epoxy+barb is a great solution. I'd get a really sharp blade and cut flush what's left, carefully seeing the wires next to it (cut away from those), and use that method.