No Fuel

2000 Tundra

Shut truck off. Went to start no fuel

Parts taken out:

dropped tank, pulled pump, bench tested and works fine.

Parts Replaced:
Battery
EFI relay
C-OPN relay
Pump
Pump screen

Put everything back together,
Battery full charge,
With fuel line off turned ignition key and fuel discharged.

Reconnected fuel line, turned key, good pressure, truck started right up.

Shut truck off went back in the shop to rest, drink a beer, and play a little guitar.

Came back out with great satisfaction that all was well and turned the key.

Epic FAIL… No Pressure, No Fuel, No Go$&@“

Deep Breath.

Stumped

I’m new to Tundra. And would like someone to explain all the components of the fuel sending unit and how you could have power at the sending unit connector, but not have the pump activate???

As I said earlier the old pump we pulled out of the tank works great.

We just wasted $183 on that…


The no fuel scenario and the fact all the relays are good, the fuel pump resistor was about .68 ohms, we tried bypassing it just because… it has power going through both legs…And power down to the connector.

What in the sending unit if it’s messed up could be causing this problem or are we barking up the wrong tree?

Any and All Help would be appreciated.

W

 

Check your crank position sensor, and more importantly, its harness. If you have the V8, a lot of times during timing belt maintenance, the crank position sensor harness will get misrouted, and nicked by belts. I can show you pics if you really need to see it, it happens often. The ECU won't trigger the fuel pump relay if it can't detect crank position. Carefully inspect the sensor to make sure it's not broken, look at the harness for bent pins, and carefully inspect for nicks and tears in the entire harness where it's near the belts.

You may also try jumpering the fuel pump resistor to verify it's not an issue with the fuel pump kicking into low-flow mode or test the resistor. Beyond that, your ECU is the "brains" behind the fuel operation, the fuel circuit and workings diagram are here. Links to the FSM are in the megathread, near the top.

Beware of LAPS parts. These trucks have, love it or hate it, sensitivities on the electronics. Stick with the OEM brand (Toyota/Denso, Hitachi in some cases, etc.). Not only that but store brand/aftermarket parts have turned into heaping gobs of shit as far as quality these days. I can't tell you how many times - especially with the fuel pump and starter, specifically - someone has come on here, like, "yeah, fuck you and your claims to only use Denso parts for those two, it's bullshit snobbiness elitism!", only to find their brand new aftermarket LAPS fuel pump or starter was either DOA, and/or it failed within the first few days/weeks/months. Store brand parts SUCK these days but people still buy them to save a few bucks, and sadly, scAmazon and fleaBay are littered with authentic-looking knockoffs so there's some places you just CANNOT buy parts from (Summt Racing and Rock Auto are always safe bets, often cheaper than scAmazon). Don't trust the aftermarket. OEM brands lasted 15+ years, they'll last another 15+ years if you buy from an authentic source, it's why they cost more money.

There are other things to watch out for, like ECU shorts etc. This thread (reply #2) kinda covers a lot of them.
There are some great suggestions from @BubbaW over here also.

Lastly, some of the earlier-model trucks have found this video helpful. Although, we've had a couple reports of wires getting pinched between the firewall and fuel pump for fuel, and in rust belt states, we had one or more people complain about corrosion in wiring connectors external to the vehicle causing fuel delivery issues ... so checking for continuity on your wires is critical too. I realize that's a lot of info ... will be curious what you find.

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

 

Thanks Shifty,

Yes sir it’s the 4.7L

The timing belt was changed not to long ago.

The pics would be nice, it would help orient me a bit and understand what you’re talking bout…

Crank position sensor harness

It’s going to take a bit to plow through this but I sure do appreciate you takin the time out to enlighten me…

I was almost done with the last load of AG Solution in the fields and the my fuel was down close to E.

Shut the truck off, loaded up, turned the key and nothing…

Im going to get on with my journey here and look at all ya sent and if you sont mind I’d like to holler back at ya along the way.

W

 

That "megathread" I linked has a lot of the info you need, pics etc. but I realize you've got a lot to pluck through. Let me save you some effort.

First, here's one example of the crank position sensor harness getting nicked. We've also seen cam position sensors get similarly nicked by the timing belt in the earlier years, one example is here, the OEM replacement part comes with a retainer clip to tuck the wiring out of the way, factory didn't, apparently. Another example of cam position sensor is here. But I don't think the cam position sensors (don't quote me on this) isn't linked to the fuel circuit (verify that in the FSM).

Second, FSM for '00-'03. The "DI-###" section is for diagnostics.

 

Is the crankshaft position sensor visible when you look up under…. In other words is the sensor mounted on with couple of bolts with the wires hangin out….

 

This should help you with location.

https://www.youtube.com/watch?v=3MPGlaBH3VI​

 

Thanks Shifty, that’s exactly what I needed.

Heading out to the parts store to find an OEM CPS…

You just saved me a whole bunch of time.

I appreciate all your help. And the cattle also.

I’ve got two more fields to get done. The tanks on the trailer are full.

The Tundra is perfect for this kinda work. Better than a tractor.

Hey Shifty, you been most helpful….

I gotta get at it.

 

Denso brand is OEM in this case. NAPA may be one of the only local stores that'll carry. Call around or check the LAPS websites online.

 

Look to make sure the wires undear the driver side cam cover aren’t loose and rubbing on the belt

 

@itsgoing2bok that's a good one ^^

Also, for examples on wire crushing etc. check this out: https://www.tundras.com/threads/2006-tundra-crank-no-start.133446/#post-3401893

That's how miniscule it can be.

 

Hey Shifty, finished the 12 pack and we’re a little closer but not there yet.

If you don’t mind could ya comment on this.

Crankshaft position sensor changed

Took the driver side door rocker panel off and found the Blue & Orange wire and the Black & White wire that goes to the fuel pump.

Grounded the Black & White
Powered up the Blue and Orange

turned the key, had pressure, truck started up and ran fine… for a bit…

suddenly pump shut off and truck died

could that be a faulty wire in the tank?

Didn’t trace the Blue & Orange back to the C/OPN or the Fuel Pump relay yet but I’m thinking bad wire or connection to the tank

Bypassed everything and truck ran fine

 

Probably not, it sounds more like your fuel pump has shit the bed.

If you went with an aftermarket fuel pump (something other than Toyota/Denso from a reputable source), I think it's time you heed advice you'll get here and purchase a Denso pump (or direct from Toyota dealership if Denso is out of stock) from anywhere selling direct to consumers from their own validated inventory, i.e. avoid buying from scAmazon, fleaBay, WallyMart, Sears/Kmart, etc. Just know if you buy direct from Toyota, I think they sell you the entire pump-and-assembly (with new sender), so it WILL cost more than buying the pump alone from Denso.

However, I know what a pain in the ass it is to change fuel pumps on trucks. So if you really want to be 100% sure, when the pump enters "DEAD" state, test continuity for your power and ground wires from the spot you tapped in, and the pump connector.

Also, I'll warn you, get a mirror and look on top of the gas tank for evidence of mice nesting.

Lastly, if you replaced the fuel pump with one that required you to cut wires, check whatever you used to splice the wires, you should NOT have used an un-sealed (i.e. need to use self-sealing) butt splice.

If you confirm there's continuity on the wires, it's the fuel pump.

If you went aftermarket on the fuel pump, it's probably the fuel pump. Aftermarket parts are THAT shitty these days, and you'd be the dozenth or more person who's had this same issue with an aftermarket fuel pump at this forum in less than 2-3 years.

 

My son-in-law gave us the truck and was changing pumps etc for the last 15 or so years.

Found the problem

Everything back to original all is well

Thanks Shifty

 

So it was a fuel pump wire connection problem??

 

Looks like someone used a standard (unsealed) butt splice when connecting the pump. I take it OP inspected the wiring and found them after suggestion above, or the recommended continuity test would've revealed it too.

Glad fuel pump replacement wasn't necessary.

 

Yes

I was running a hydro unit on the back of a trailer pulling a ton plus.

Thing that caused the problem was when I started hitting a steep grade left to right so the truck was tipped to the side at a good angle.

Apparently the fuel sloshing around was moving the negative wire on the fuel pump side to side at a good rate.

Once I turned the truck off it was over.

It’s been a long time since I’ve gotten into something like this and I was definitely rusty.

I bench tested the pump and wiring harness the first time and everything seemed ok.

once I reinstalled everything and bypassed the whole system to eliminate any complications the truck started then died after awhile.

That’s when I knew nothing ahead of that point was a problem, it was all in the tank.

took the tank out, pulled the sending unit with pump.

pulled the connector off the pump on the bench and with a 12 volt bench power supply I tested the pump only and it was good.

put the connector back on and attached power leads to sending unit connector and nothing.

Wiggled the negative wire and there it was!!!

Changed out the butt connectors

used high grade connectors with silicone heat shrink and all is well . All sealed up, right size connectors.

if I wasn’t such a dump ass this wouldn’t have taken so long.

I went based on a history and didn’t question the integrity of the past work.

This is an example of one butt connection causing hell for 15 years.

I hope I won’t be dealing with anything like that again; however, that is wishful thinking.

During this process I found there is a ground short.

I pulled the positive battery post wire, took the continuity tester and clipped on the positive lead and then touched it to the post… it lit up.

I started to pull fuses and when I pulled the (Dome) fuse the light dimmed.

that’s all I got for now.

Eas able to get the last 300 gallons on the field

Thanks Shifty.

 

Fuel pump connection problem

The End

Thanks Shifty

Sorry for boring you with the details.