2006 Crank, no start,

Tundra started up fine, went 50 feet, I stopped and truck shut-0ff clean. I have check engine light and codes for O2 Sensor problem only. I have spark, will run with starting fluid sprayed in intake. This same thing happened 2 years ago, I never really found the problem. 2 years ago I replaced the crankshaft sensor, that did not immediately solve the problem, but after many days of trying to find the problem, one day it cranked and started, same thing now 2 years later. Only about 130,000 miles on truck. I want to be able to get power to the fuel pump to rule that out, is there a connection in the wiring harness where I can access the wires going straight to the pump? What wires? I am in a remote part of Alaska, truck is on a muddy road, and constant rain. Advice and/or recommendations greatly appreciated. Thanks

 

Just for shits and giggles, when was the last time the timing belt was replaced? If "never", you may want to pull back one of the timing covers and confirm it's still intact.

Otherwise, there's a wild variety of things that could be wrong, and when you mention constant rain, and intermittent issues, I immediately think water is getting into something it shouldn't. Like the ECU, kinda like this guy over here, or the main fuse/power distro block inside the cab like this guy over here. When it dries out, "magic", things work. Gets wet again, womp-womp, no joy.

If you took out the constant rain suggestion, fuel pump is where my money would be, but replacement requires dropping the tank which is a PITA. Given you confirmed spark, the only other thing to do is to confirm the fuel pump is doling out fuel. There was one guy on here recently who was able to get under the truck, pop the power/ground leads off his fuel pump, and use a battery pack to power his fuel pump up. But really, if you can turn the truck on and throw a pressure gauge on the fuel line, then crank while watching the gauge, that should tell you what you want to know.

Short version though, I'd check the fuel pump, check the ECU for water damage (if either floorboard is wet, could be a good indicator of water intrusion), and go from there.

 

Oh, and Alaska is cold as shit, and I assume you have rodents/varmits. Did you check the MAF to make sure nothing was clogged in it, check the air filter and under it to make sure nothing was chewing on it, look for chewed wires behind the glove box, in the engine bay, etc.?

 

Just turn the key to on position, and go down to fuel tank area to hear if the fuel pump make humming noise, but I’ll check the fuel pump relay and fuses first

 

Is this true on a 1st gen truck? I don't think the fuel pump engages on 1st gen until you turn it over. I swear this has come up a few times in the past and someone corrected me when I suggested you could just turn the key to the ON position.

 

Fuel pump relay checked-good, c/op relay checked-good. C/op relay removed and switch side sockets jumped, cranked/ no start. I tried putting 12volts to the switch side of the Fuel Pump Relay hoping to run the fuel pump, nothing.

 

I know there is a wire bundle connection under the drivers seat, some wires continue toward the back of the truck. Does anyone know if any of these go to the fuel pump, I don't really want to have to squeeze under the truck in the mud to try and find the wires going to the fuel pump. It ran fine, and then this crank/ no start all the sudden, would really like to verify the fuel pump is bad before replacing it. I am thinking I will cut a hole through the bed of the truck to replace the fuel pump if I have to replace it, Is that a viable option?

 

https://youtu.be/VoerlgT8pck

 

Correct. Runs while cranking, if the engine doesn't fire it shuts back off, if it does fire it keeps running.

 

ya, but it will go on for a few seconds to built up the pressure

 

1st gens don't. The pump will not run until you start cranking. No fuel pump prime. It's a older Toyota thing. My 96 Camry is the same way.

 

I can confirm this @Winning8, when I heard this the first time I didn't believe it. I've owned so many vehicles where, when you open the driver door, you'll hear the fuel pump kick on and prime, or you turn the key to ON w/o cranking and you hear the fuel pump kick on.

But sure enough, just went out to the truck before I posted my comment. When you open the driver door in my '06, or you turn the key to ON without starting, you don't hear jack. Stuck my head under after clicking the key forward, nada. Put my hand on the tank, turn the key forward, nothing.

I dunno if there's some means by which the fuel pump maintains pressure after shutoff or what, but ... it's almost instant-start when I crank, but no typical 1-2 second fuel pump pressurization noise in my '06. I was primarily a GM guy prior to this, with lots of other brands sprinkled in over the decades, so this was, like, totally bizarre for me.

 

My '98 Land Cruiser has the same 2UZ engine. The fuel pump runs once keyed "on"...it runs for a few seconds until it reaches pressure, then stops.

 

Toyota just couldn't make up their minds apparently.

 

Could it be that the system is "Smart?" If the pressure sensor says to the fuel pump: "Hey, I've still got enough pressure. You don't need to prime."

The ECU could be taking the pressure reading and deciding whether it needs to prime or not. @w666's land cruiser may just be slowly bleeding the pressure off back into the tank if that's the case???

I don't know. I have no evidence to support any of this. Just a thought I had.

 

Thank you, that is just what I needed. very helpful.

 

If you end up finding it's the pump, come back and holler at us so we know. Getting that confirmation can make a huge difference for the next guy popping in with the same symptoms.

 

New update: I thought this would solve the issue, but I opened up the wiring harness per the youtube video and the wire colors shown in the video are not on my 2006 tundra. Does anyone know where I can get a wiring diagram or something to tell me what color wires should be going to the pump in a 2006 Toyota Tundra 4.7L V8? The video was great, but those wires don't exist in my bundle.

 

https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/

 

https://www.tundras.com/threads/2006-fuel-pump-power-wire.95231/

blue black and white black

 

Thanks for all the help, at this point I still have not been able to power the pump. Will probably be the end of the month before I can move it to a location to replace the pump.

 

I replaced the fuel pump. Still cranks-no start. Will still fire up and run with starting fluid sprayed in the intake. Confirmed continuity from blue wire/blackstripe to the fuel pump connection. confirmed ground from the middle thickness, white/black stripe in the wiring bundle, there are 3, located under the carpet, under the drivers seat. Like I said, I had this same issue 2 years ago, I never found the problem, one day it just fired up. This time I changed the fuel pump.
What else shuts the power off to the pump, and how do I get rid of it. Still just the O2 Sensor codes.

 

After getting on this forum, I am now aware of the ticking time bomb of the timing belt, and the issue of getting antifreeze into the transmission. With the crazy prices of new trucks, l was planning on doing the preventative maintenance, but I need to win this battle first.

 

The video in reply #8 walks through jumpering power to the fuel pump to hard-wire it at the relay box under the hood. Have you tried that yet?

If that fails to fire up the pump, you should probably test for shorts in the wiring.
If that does fire up the pump, there are a few other things that can cause the fuel pump not to engage or stay on post-ignition:

• Fuel pump relay (in engine bay relay box)
• Circuit opening relay (in engine bay relay box)
• Crank Position Sensor (on-block, check wiring, replace sensor w/OEM)
• ECM failure or wiring damage (ECM is behind glovebox; sometimes rodents chew back there)
• Possibly Fuel pump resistor (on older trucks, it's the silver finned thing on top of driver side fender, under master cylinder, on newer trucks, it's the silver finned thing on top of passenger side fender, next to the power steering reservoir)
• Possibly EFI relay, but I'm not 100% positive if I'm reading the diagram right (in engine bay relay box)

Cheapest parts to replace are probably the relays, but you could potentially also use a relay tester to confirm those? I'd stick with Denso brand if I were you. Call a dealership, they can probably get you a part number for each. If you get the part number, you can order direct from Toyota at a discount using this info. Same deal with the crank position sensor. These are lower-cost parts you can throw at it. DO NOT BUY THESE PARTS ON scAMAZON. You will likely get very convincing counterfeits.

Your ECM will have a part number printed on top of it, in the format of XXXXX-0c0XX. If you have any junkyards near you or can find a working used one on eBay, you could go that route. If it doesn't work, you can always re-list/re-sell on eBay. If you pull it, it's a good idea to open its clamshell and look for water damage.

Here's the FSM for your truck, on mine, looks like page 873 contains the fuel pump circuitry (search for: DI-600):
https://drive.google.com/file/d/0B-5MhfqaHsHObmt6RDVhOGtKWjA/view?usp=sharing

Here's the diagnostic breakdown with the sections to search for and check for starting - check the 2nd row in the grid and follow the pages it takes you to (search for the section, since the links inside the PDF are broken). It'll walk you through testing the ECM and stuff. I still wouldn't be surprised if this is rodent-related, but maybe it is the ECM, a relay, or CP sensor:

 

Do you know what the resistance should be on the fuel pump resistor and fuel pump driver?

 

Check the FSM. I linked it above. It should have that technical information.

I'm in the mountains with patchy internet. Wouldn't be able to look until later.

 

Check the FSM. I linked it above. It should have that technical information.

I'm in the mountains with my dog and patchy internet. Wouldn't be able to look until later.

 

Does anyone have a wiring diagram for the fuel pump driver circuit?

 

Check the FSM. I linked it above. It should have that technical information.

I'm in the mountains with my dog and patchy internet. Wouldn't be able to look until later.

 

The FSM shows the resistor, not the driver. Or could the driver be known by another name?