Fuel pump issues or problems with electrical? (1 Viewer)

[hickuptruck]

Well, heres the most uninspiring picture I've got of my 100. Its an 02 with 192k miles. First time its left me stranded.

It stalled on me pulling out of a parking lot (had just recently driven 25 minutes on the freeway). I tried to start it again and it only cranked without start. Tried probably about 5 times in 5 minutes starting it. I then gave it 15 minutes while I was on the phone for a tow truck, and it started. I only drove about 60 seconds and 1/4 mile before it stalled again and wouldn't start back up. I then swapped out the 20 amp EFI fuse with a good extra one, checked the fuel pump relay next to it (it was really clean without any corrosion), and tried starting it up again. It wouldnt start.

Tow truck came and an hour later, it dropped it off in my driveway at my house. I could start the LX without any issues, and I let it idle for 5-10 minutes without it stalling. I even held the throttle down at 2k rpms in N without it stalling.

Whats the verdict? Fuel filter is 15k miles old, and fuel tank was at 1/3rd of a tank. Should I start with getting a new Denso fuel pump?

 

[JunkCrzr89]

Turn ignition to ON, but don’t crank the engine, and listen for the fuel pump. It should “click” and not “whine”. But your symptoms do sound like a failing fuel pump to me. You could also just have bad gas or loose ground cable, etc.

 

[ramangain]

I slways pimp out the "loose ground" fix since it is free and easy.

Any stored codes?

 

[hickuptruck]

Turn ignition to ON, but don’t crank the engine, and listen for the fuel pump. It should “click” and not “whine”. But your symptoms do sound like a failing fuel pump to me.

Yeah I listened, no audible noise coming from under the carpet.

I slways pimp out the "loose ground" fix since it is free and easy.

Any stored codes?

No CEL. Going out right now with techstream to see if there are any.

 

[medtro]

Did you have blinking security light when it cranked with no start? I would get fuel pressure before swapping new fuel pump.

 

[jerryb]

you have techstream and haven't checked the fuel pump yet? While you can hear it run you can't check it's temperature or volume flow without too much extra work. Just cheaper to replace it unless you know it's less than a few years old.
Not sure why everyone doesn't have a cheap set up to check rail pressure.

 

[abuck99]

you have techstream and haven't checked the fuel pump yet? While you can hear it run you can't check it's temperature or volume flow without too much extra work. Just cheaper to replace it unless you know it's less than a few years old.
Not sure why everyone doesn't have a cheap set up to check rail pressure.

For the greater good- whats a good "cheap" set up and the (or your) process for checking FRP? .....

 

[jerryb]

toyota tool # 09268-45014 should be sufficient, i don't know about cheap

cheap can be a russell 640700 = a take off banjo bolt with 1/8" npt port. then any wet gauge 1/8" npt male.
But assembly required each time.
Both sides of the crossover fuel pipe banjo bolt are m12 X 1.25
A permanent schrader valve can be installed in combination with a take off bolt.
Venting that would be a dribble when you release it or want to remove the hose/gauge set up. Good for leakdown rail test, then when an hour or four have gone by just uninstall with minimal fuel leak.
TEst kit from harbor freight should be fine, plus a take off banjo bolt. Take off meaning an open port on the top. 30$?
Leaking injectors is the thing your looking for, they must be leaking pretty badly for pressure to drop from 40 to 21 psig in less than 5 minutes.
Pay someone to do the test if you don't ever want to do it again yourself.




oveboard and unnecessary info below.

There are fancy aluminum QD fittings to make it nice for a permanent install where you just connect your gauge and look, no venting. minimal leak when removed or set with the engine running.

At the end of each rail, fan side there are ports with m14 X 1.5 plugs in them. You can put anything in there also, temporary or permanent.
MAMBA on ebay has excellent adapter fittings for all. M14 X 1.5 to 1/8" npt port
A common electric sender and gauge might be 60$ and a fitting for 15$. There's no real reason to constantly watch fuel pressure on this truck. But it's handy.

realize that NPT isn't going to seal well at all. You can ignore that for a regular one time test. But to really seal a schrader valve in a 1/8" npt port you need something.
I use loctite SF 7649 primer and loctite 545 sealant (not cheap) I've used both for more than 10 years now to seal fuel fittings. Im' sure permatex has a one tube solution also for less money.

I used a QD on this truck first, then i switched to an electric sender when I wanted a temp probe and pressure sender in the rail.

 

[jpd motorsports]

Currently chasing same issue 1999 lx. leaning towards fuel pump on mine. same symptoms as yours. And i just re cleaned, greased all the grounds and power cables. My thinking is the pump is getting hot and that little bit of time 20-30mins let it cool enough to start for a small bit, and i can also push down on the fuel pressure regulator while somebody ic cranking and "pump it" basically.

 

[jerryb]

That's the other decent way. Bump the supply pressure with a brake line clamp, briefly. Just realize you're back pressurizing the supply line all the way back and you have no way to stop before you go too far. Then you know you have a volume issue and or temp/age. Be careful.

check voltage at the fuel pump (tank cover) also. There is 100% chance you're not getting battery voltage. this issue just makes it worse than it already is, and mostly likely planned for by the maker, but over 20 years it could be significant.

 

[sacman]

I'm chasing similar issue and despite rigging up the EFI bypass, which helped for a few trips, it won't even crank now. I'm ordering the fuse box and will try to diy. I scanned for code using OBDII reader and it came up clean without any issue which leads me to electrical wiring.

 

[abuck99]

toyota tool # 09268-45014 should be sufficient, i don't know about cheap

cheap can be a russell 640700 = a take off banjo bolt with 1/8" npt port. then any wet gauge 1/8" npt male.
But assembly required each time.
Both sides of the crossover fuel pipe banjo bolt are m12 X 1.25
A permanent schrader valve can be installed in combination with a take off bolt.
Venting that would be a dribble when you release it or want to remove the hose/gauge set up. Good for leakdown rail test, then when an hour or four have gone by just uninstall with minimal fuel leak.
TEst kit from harbor freight should be fine, plus a take off banjo bolt. Take off meaning an open port on the top. 30$?
Leaking injectors is the thing your looking for, they must be leaking pretty badly for pressure to drop from 40 to 21 psig in less than 5 minutes.
Pay someone to do the test if you don't ever want to do it again yourself.




oveboard and unnecessary info below.

There are fancy aluminum QD fittings to make it nice for a permanent install where you just connect your gauge and look, no venting. minimal leak when removed or set with the engine running.

At the end of each rail, fan side there are ports with m14 X 1.5 plugs in them. You can put anything in there also, temporary or permanent.
MAMBA on ebay has excellent adapter fittings for all. M14 X 1.5 to 1/8" npt port
A common electric sender and gauge might be 60$ and a fitting for 15$. There's no real reason to constantly watch fuel pressure on this truck. But it's handy.

realize that NPT isn't going to seal well at all. You can ignore that for a regular one time test. But to really seal a schrader valve in a 1/8" npt port you need something.
I use loctite SF 7649 primer and loctite 545 sealant (not cheap) I've used both for more than 10 years now to seal fuel fittings. Im' sure permatex has a one tube solution also for less money.

I used a QD on this truck first, then i switched to an electric sender when I wanted a temp probe and pressure sender in the rail.

Thank you

 

[medtro]

I'm chasing similar issue and despite rigging up the EFI bypass, which helped for a few trips, it won't even crank now. I'm ordering the fuse box and will try to diy. I scanned for code using OBDII reader and it came up clean without any issue which leads me to electrical wiring.

You have a 2003 model, some of the electrical stuff including fuse box is different than the 2002 model discussed here. Have you tried to trouble shoot it systematically or just throwing new parts at it? The fact that it won't crank now is a good news, that gives you a specific area to look at.

 

[medtro]

For the greater good- whats a good "cheap" set up and the (or your) process for checking FRP? .....

I have been watching this one and haven't found a cheaper one with the same adapters.

Amazon product ASIN B07LF26ZTJ

 

[graveling]

I have a 2000 tundra in which the Fuel Pump died at 270K. It's one of the few parts I hadn't changed over the years, so I bought one about a year back to have with me just in case. Sure enough, it died at my cabin in MI. A few month earlier I had watched a video in which a mechanic advised whacking the tank with a rubber mallet a few times. Apparently these motors get carbon build on the brushes which causes them to not turn when it stops in just the right position. Sounded like BS, but sure enough it worked. It allowed me to get the truck to a place in which I could drop the tank and replace it. I'm going to replace it on my new to me 99 LC, as I know it's not been done. Not looking forward to it because that metal protector is rusty as h#ll.

 

[hickuptruck]

LX fired right up first start and strong this morning. Plugged in techstream, nothing out of the ordinary showed up. Ran the fuel pump test - the fuel pump could be heard turning on under the carpet without any whine, and fuel injector tests ran normal numbers. Drove around for 10-15 minutes, and everything seemed ok.

Still waiting on the fuel pump and fuel pump tester. I think thats going to be the solution, a new fuel pump at 192k miles. I dont have any flash red key when the ignition is on, so that's good news that it isn't EFI relay/fuse problems?

 

[medtro]

I dont have any flash red key when the ignition is on, so that's good news that it isn't EFI relay/fuse problems?

May be. This is not a good indication when the engine cranks and starts. It should start when the security light is not flashing. You need to find out if it is flashing when the engine doesn't start.

 

[JunkCrzr89]

Not looking forward to it because that metal protector is rusty as h#ll.

Don’t have to drop the tank on 100s. Just pull up the rear seat and pull back carpet. Access hole is in the floorboard!

 

[medtro]

Don’t have to drop the tank on 100s. Just pull up the rear seat and pull back carpet. Access hole is in the floorboard!

Need to remove seat IIRC.

 

[JunkCrzr89]

Need to remove seat IIRC.

Yep. That’s what I meant but didn’t convey