Crank No Start

Hi Everyone,

I've been a lurker for years, but alas I need some help. Beyond this weekend running through and testing per IN-27, any other ideas? I'm hoping something I missed something easy.

2001 Tundra
4.7 V8
Access Cab

Last week my truck was sitting for a few days at an airport lot and the attendant didn't close the door all the way, light stayed on and killed the battery, now it cranks but no start and had to have it towed home. I replaced the battery as it was having issues holding a charge and dropping too much when cranking.

Symptoms:
Engine cranks well, but no start.
No communication via obd2 and I know this worked previously as 2 years ago my O2 sensors threw codes. I tested my scanner against another vehicle, and also a loaner one, both with the same "no communication".
Using starting fluid, the truck runs.

Things I've checked so far:
Brand new battery
Fuel pressure is 44PSI when attempting to start
Checked all fuses (multimeter and tester light) and relays (9v and multimeter)
Timing belt is in good condition (didn't pull other shroud off, but only replaced 30k miles ago), but still tight and don't think it would have slipped
Crankshaft position sensor (sensor was good)
Checked voltage on ECM between +B and E1 and it's at 12.2V

 

But does it STAY running, is the question? If it doesn't that suggests a fuel delivery issue, but you said 44psi so that can't be the case, right?

Sounds like your scanner is borked if not working with 3 vehicles.

Dumping the entire battery would force the ECU to unlearn how to run. That can lead to all kinds of fun stuff, but I'd expect it to get past it after a drive cycle. Given all this started after the battery drain, it's what I'd think. I doubt rodents chewed your stuff while 2 days at airport.

Crankshaft position sensor is fine, and the wiring is fine? i.e. didn't get misrouted during your recent timing belt install, and didn't get nicked? Again, not thinking it's the culprit, since this started after.

Did it rain outside while you were at the airport? Does the windshield have any cracks? Was the windshield replaced at any point in the last few years?

 

I've tested two different known working scanners against the truck and both don't work.

Rain in the PNW? Yes...but it's been doing that for decades on the truck.
No windshield cracks or replacements.

I checked the crankshaft sensor wiring and it looked good too. It was routed the proper way which was nice.

It does run if you keep up the starting fluid, which makes me think it has to be fuel related...if though it has pressure.

I checked some more sensors and I'll check the injectors to make sure they're good, but it would be surprising to have it impact those and and OBD2.

 

Most cars I've owned have an OBD fuse in the fusebox. Is it possible yours is blown?

When you reattached the battery, did you make the mistake of attaching the positive cable last? It's a good way to blow fuses, including the EFI fuses in the engine bay... Did you check the EFI fuse(s)? Did you check all the other fuses under the hood? Just tossing some thoughts out at you.

RE: fuel pressure ... Are you sure the truck maintains constant pressure, or are you seeing the pressure drop while running?

 

EFI fuses have been tested and I went through and tested all the fuses and relays again for the 5th time just to be sure I didn't miss anything.

I did see this video though https://www.youtube.com/watch?v=9wLrTjeb9TY if that applies to 1st gen Tundras. I pulled all the fuses and the tester light was still on...