Fuel pump issues

I went out to start my 2002 Toyota Tundra 4.7 SR5 and it will crank, but won’t start. So I listened when I turned on the key, and no fuel pump. I’ve taken all the relays out, C/OP, EFI, and Fuel Pump, and they all seem to be functioning correctly and have continuity. I make a jumper wire and went directly off the positive terminal of the battery and connected it directly to the fuel pump female end of where the relay goes in and the pump comes on. I don’t have a pressure gauge, but felt the lines coming up from the tank and can feel pretty good flow, but the truck won’t start. I can’t figure out why it won start if the fuel pump is jumped and working. I’ve pulled all fuses and checked them too, all fine. I also threw a multimeter on the wires for the pump that run along the door and nothing when the key is in the on position or cranking, but when I have the jumper wire I get 12v.

It usually fires right up, before today. Only 96,000 original miles. Anybody have some input for me? I really appreciate any insight. This is my first thread, forgive me if it’s long winded.

 

Boy you’ve got me stumped, have you tried to pull any codes? Do you have spark?

 

You need spark and working injectors for the engine to run. Did you check the fuses a multimeter to confirm that they are good? Check for chewed or loose wires? Confirm your timing belt is not broken?

 

Just figured it out, I’m an idiot. I had the EFI relay out when jumping the fuel pump bc I was testing all connections and the 3 relays that could possibly be bad. It fired right up when I jumped the fuel pump off the battery. So looks like a fuel pump relay. Thanks for the replies and I’ll let you know if that solves it. Appreciate it. Man I was stumped when I first jumped the fuel pump and it wouldn’t fire. Obviously I need the injectors and just was trying to eliminate too many things at once. Thanks again.

 

It was the circuit open relay, not the fuel pump relay like basically everybody says to check. It really should be fuel pump relay #1. Thanks again. Truck runs great.

 

New to the site and the whole Forum scene!
But I have a strange issue. I will call it the ghost fuel pump issue!!
I have a 2000 Tundra with a 4.7 V8 it has 304,000 miles on it I bought is used two years ago and it was running great until 3 weeks ago. parked the truck at a job site and it would not start again. It would crank but Not Start.
Towed it home and it would start if I sprayed starter fluid in the air intake. Towed it to local Toyota dealership and was told that they checked it and IT WAS the fuel pump MALFUNCTIONING and it would cost $1400+ to replace it!! Told them that I paid $1200 for the truck and that was not going to happen.
Towed it home and bought a new pump, a transmission jack ((it had basically a full tank) to replace the pump. I syphoned as much gas as I could out of the tank as possible to make it lighter and was checking the gauges for amount of fuel in the tank and I just tried the ignition and the truck started right up and it has been running just fine for the last week. Here are some things that might be worth mentioning:
- The truck got a new frame due to the recall, I have heard of shoddy work and/or loose connections, hoses etc.
- The temperature dropped pretty drastically overnight last week.
- The timing belt was changed about 100,000 miles ago
- The dealership says they checked the fuel pressure (don't know what they found)
- The dealership says they think it is the Fuel Pump Malfunctioning. I guess they don't want to commit to a dead fuel pump?
- In PA we have to get annual state safety inspections - The mechanic told me that I had a fuel leak on my fuel tank!. When I got under the truck I could smell gas and the top of the tank was wet to touch. That was 10 months ago, but I have kept an eye on it and have not seen it again or smelt any gas. Used to fill up the tank until recently when I got an engine light for charcoal canister Evap code and was told this happens when you top off my tank regularly!!!!
- I have checked and replaced the Relays -(Fuel pump relay and C-Open relay) since there are no fuel pump fuses
- I don't believe it is the crank shaft position sensor, since the truck started when I spraying starter fluid in the air intake.
Sorry for the long story but I wanted to give all the information I had to see if anyone out there has had something similar since I don't want to keep replacing things if not needed BUT I would hate to get stranded in middle of nowhere if it is the fuel pump!!!

 

Just to summarize, making sure I didn't get confused in that wall'o'text...

• Suddenly fuel pump wasn't pumping
• You know it wasn't mice chewing the wires, because you swapped out the fuel pump, and saw the wiring then, and wiring was OK
• (Note: We need to know what BRAND of fuel pump and where you bought, since OEM is bulletproof and aftermarket are shit, prone to fail)
• Fuel pump was working great after replacement, at least 1 week
• Suddenly fuel pump isn't working again

Mice love chewing things up, soy-based wire casings, fuel stuff. We see it here a LOT. Always the 1st thing to check.

If it starts with starter fluid, that suggests spark is fine, but adequate fuel isn't getting into the cylinder to ignite. In this case, it's never the fuel filter being clogged, it's typically that something isn't tripping the fuel pump. Are you able to test for fuel pressure while cranking to test that theory?

If I understood the diagrams right, the fuel pump usually only kicks on when you're holding the key forward, and after it starts, only if the crank position sensor is working correctly and telling the fuel pump that the engine is going. There's a silver finned fuel pump resistor under the brake booster on the driver side for older trucks, and on newer trucks, a silver finned fuel pump resister on the passenger side fender next to the power steering reservoir which are also key components.

There's a connector, I think under the driver's seat on some years/models, where you can jumper to force the fuel pump on, you can use that to see if you hear the fuel pump kick on, and to test pressure without the key forward. Someone has a diagram of the IC on here somewhere.

More info may be gleaned here, along with diagrams.

If you choose to ignore that, here's the fuel pump circuitry if you want to understand how the fuel system works.

Here's a link to some diagnostic videos that may help you diagnose starting issues:
https://www.tundras.com/threads/2005-ac-wont-start-fuel-system-problem.113385/#post-2921783

Meanwhile,

 

Thanks Shifty,
Just to make some corrections here,
The fuel pump was NOT changed
Truck would crank and not start previously and Toyota Dealer said it was a Fuel pump malfunction and it would cost $1400 to replace.
Towed it back home
Siphoned gas out of the tank to make it lighter to remove.
I don't know how to check fuel pressure and I don't have the equipment to do it.
It now starts with no problem.
I just don't want to be stranded somewhere
Has this happened to anyone before? Should I check anything?

 

What about it being wet on top and smelling like gas? Does it still do that? If so, you need a new gasket on top, which requires removal of the pump. I'd get an OEM pump and replace it when your tank gets low.

 

Tell us what cab your truck has so we know how hard swapping the pump is and what details to give you. For example, on older access cabs, you drop the tank. Newer access cabs, you can unbolt and lift the bed a bit.

"Fuel Pump Malfunction" is pretty generic. That could be a failure in the wiring/circuitry or a failure of the pump. It's unfortunate they weren't more specific.

Some of the owners here have had cases where they drove the truck a while to get it up to temp, then parked for a short period (i.e. truck still warm), and when they went to start, it just kept cranking w/o firing. There was some skepticism maybe it was the fuel resistor, but ... it never came back for one guy, and is sporadic with the other.

I've personally had a similar case, except when I turned the key forward, everything went black. Still no clue what that was about, but after 3-4 minutes, it self-resolved.

Yes. Did you check the video I linked to? You really should, if you haven't, it'll explain how the fuel system works on a 2002. Except he's wrong about just turning the key to "ON" position, that won't engage the pump (it actually engages when you turn the key fwd to crank).

First things first, watch that video. As a cursory, check for chewed wires on top of the tank, leading up to the tank, etc. Check the wiring for your crank position sensor. to make sure it's intact and firmly plugged. Next, check the fuel pump circuitry link I posted. Look at the diagram, you can confirm what I'm saying about the fail points that would cause the fuel pump not to pump, other than the obvious (fuel pump relay, etc. watch that video). If it happens again, consult the video to troubleshoot through it.

I know you're saying you've only got 96k miles, but understand LACK OF USE / AGE WITH LACK OF USE kills things just as easily (or more easily) than mileage. These trucks are built to be driven. I have 73k miles on mine, you do not want to see what I found under my valve covers from all the short trips the previous owner took - it looked like it was coated in molasses.

I've been told my whole life that consistently running your tank to 'E' causes the excess heat in the fuel pump, because many EFI vehicles have the fuel pump immersed in fuel, using the surrounding fuel to act as a heat dissipater. If there's no fuel in the tank, unless the OEM baffled the fuel pump in a way that keeps it submerged, it will heat up more frequently, possibly shortening the life.

Dealership told you it's a fuel pump malfunction, I'd take it to heart. If I were you, I'd proactively swap the pump specifically with another OEM pump (and any associated seals, if applicable, your pump setup is different than my '06). At 20 years old, that fuel pump did you awesome justice, but it may be on its way out. You should be able to get an OEM for a couple hundred bucks and do the work yourself. I can link you to a video of the process.

I can't stress enough. OEM pump or Denso brand at the local parts store. DO NOT buy it from scAmazon or fleaBay unless you like counterfeit parts.

Alternately, wait until it happens again. When it does, go into the relay box under the hood and tap the fuel pump relay shown in the video. Sometimes relays go on the fritz, a lot of times you can firmly tap a failing relay and it'll engage. You may just want to proactively replace the fuel pump relay with a OEM/Denso replacement.

 

PS - don't buy parts directly from the dealership parts counter. You'll pay full MSRP. If you order through https://parts.toyota.com you can see a substantial discount.

More info can be found on using the Toyota Parts system lives in a sticky topic at the top section of this forum.

 

Sorry for not writing back for a while. After driving it for a few days The truck wouldn't start again, towed it home and decided to change the fuel pump. Got a fuel pump (with an installation kit) from Rock Auto for $28 the only issue was the electrical connection did not match the Toyota connection. I dropped the Fuel tank, emptied it out and cleaned it. Installed the fuel pump. The scariest part was making electrical connections inside the tank that would be exposed to fuel but after checking a few videos on youtube realized that gasoline is not a conductive liquid and it is ok to have open wire connections (still scared of the whole idea!!). I decided to replace the tank fill hose and tank breather hose since there was some gas on top of the pump assembly. These hoses are very expensive - if anyone has a less expensive way of getting them please share.
From what I gather the original pumps (304,000 miles) could stop working and then come back and work intermittently!!
I have been driving the truck since fuel pump replacement with no problems.
Thanks for all the input.

 

Awesome news - in-tank fuel pumps are easily one of my least favorite jobs. And you really never know when they're gonna go out, and no two ever seem to go out the same way.

 

Anyone know how much the Denso fuel pumps go for and what’s their price?

 

Depends on the year. All are submersible, but I'm pretty sure all the earlier trucks have a caddy, and you can just swap out the barrel pump directly. The later models like mine it's one whole assembly.

Best thing to do is to hit the Denso site and plug in your make/model/year and look up the part: https://www.densoautoparts.com/#find-my-part

I peeked in on your '02, and it looks like just the pump alone runs about $75-95 depending where you buy. Denso also sells a pump and strainer kit to refresh everything, which run anywhere from $70-125 depending where you buy.

 

I don't know yet, but the denso find my part website is listing two different fuel pump kits. Strainers, and shit included.

 

Yup, that's about what they had when I ran @Jack McCarthy's truck:

(You can check pricing/availability here, since some items are on nat'l backorder)

 

Other than the strainer length, I can't figure out any difference. Can you?

 

The one with a black body is longer in length, other than that, I was stumped. I admit, I didn't check specs. Maybe one is higher duty cycle, pushes more GPH, or ??

They sell the strainer and the foam tank seal separately, seems more efficient to buy the pump and strainer as a package though.

 

I wonder if they'd both fit, and it doesn't matter or if it does matter? I'd hate to order, get the parts, drop the tank, and then find out it's too long. That'd be a yuuuuuge bummer

 

Yeah but at least you got the Corolla if you have to wait on an exchange in parts. For me it’s right the first time or I’m getting Lyft or taking the bus to work.

 

That's a good point. I didn't consider that...

 

Damn. I hope I don’t need an ac drier or evaporator. Those are discontinued. Also the gas tank seal is discontinued as well. Guess I’ll be using FIPG there.

 

I just figured something out on the denso site using RockAuto as a parts Gauge.

The denso site shows V6, and V8 parts regardless of your engine selection. Here's a rockauto link to a fuel pump for my V6. The part number matches one that @shifty` has highlighted in his post above. (Pic is link)


Here's my selection on that website.


Here's the listing for ignition coils. One for V6, and one for V8.






So to summarize, and stay current with this thread.... the 950-0107 pump strainer kit should be for the V8.

 

For gaskets, I'm sure you can get aftermarket. In cases where I can't, I go to scAmazon and buy XCEL 1/8" neoprene foam pads (or sheets) in whatever size makes sense to make the gasket. I've done this for a few things, repairing firewall and gasket leaks on things that don't have a replaceable gasket.