Crank but no start after rebuild (1 Viewer)

[nagrom46]

Hello all.

I’ve spent the better part of the last year learning and rebuilding the motor (96 lx450).

Tonight was the first start. Pulled the fuel pump relay, turned it over several times. Plugged relay back in, turned it over and it started. Ran it for approximately 10 seconds, then turned it off.

Now, it will crank but will not start.

My CEL is on when the key is in the “on” position.

I’m just confused as it started and ran, and now it doesn’t. Not sure what to do first.

I did drain the gas tank and added in approximately 2.5 gal of fuel. Maybe that’s not enough in the tank for the pump?

 

[Fj80oregon]

Did you build oil Pressure when cranking? Start with the basics, electrical connections, spark, fuel and air. How’s your fusible link? Timing?

 

[nagrom46]

Yes. Fusable link is new. Went through all connections. All appear intact. As far as timing, I’m hoping it’s good as I followed the FSM while reassembling.

 

[nagrom46]

Had a little time this morning to take a better look.

I am getting spark.

Remove return line from fuel pressure regulator. Nothing.

My diagnostic skills are nonexistent at best and I have a new Toyota fuel pump I was going to install anyway. I’ll do that and add a bit more gas and give it another whirl.

If that fails as well, I’ll go ahead and invest in the proper electrical tooling and get to learning that side of things.

 

[Fj80oregon]

Fuel pump relay? And fuses related to fuel pump. Maybe your efi relay needs replaced.

 

[nagrom46]

I don’t have a way to test the relay. Visual inspected and switched around fuses. Same result.

Put 12V to the fuel pump per the FSM, and got nothing. Pulled the pump and found this. Yikes.

 

[Malleus]

No surprise; that was going to be my guess.

I'd guess the engine was running on the fuel in the supply line and when that was exhausted, it quit.

Do what you can to clean the trash out of the tank, too. If you have a low volume, low pressure sprayer, like a garden sprayer, put a gallon of fuel in it and spray the interior. If you can get the trash into the sump area, you'll be OK. Make sure to get it off the walls, where the fuel sat, and around the seams where the baffles meet the tank, as best you can. Make sure to install a new gasket on the drain plug.

The new pump should have a sock on the pickup. Make sure it's well seated and take care that it doesn't become dislodged as you install it.

I'd also recommend that you blow out the supply line, from the filter to the tank, if you can, and replace the fuel filter. It's a PITA, but you should only have to do it once.

 

[nagrom46]

No surprise; that was going to be my guess.

I'd guess the engine was running on the fuel in the supply line and when that was exhausted, it quit.

Do what you can to clean the trash out of the tank, too. If you have a low volume, low pressure sprayer, like a garden sprayer, put a gallon of fuel in it and spray the interior. If you can get the trash into the sump area, you'll be OK. Make sure to get it off the walls, where the fuel sat, and around the seams where the baffles meet the tank, as best you can. Make sure to install a new gasket on the drain plug.

The new pump should have a sock on the pickup. Make sure it's well seated and take care that it doesn't become dislodged as you install it.

I'd also recommend that you blow out the supply line, from the filter to the tank, if you can, and replace the fuel filter. It's a PITA, but you should only have to do it once.

Great suggestions. Thank you. I’ll do all of that.

As for the fuel filter, it’s brand new. Still replace? Massive PITA with the engine back in the truck from the looks of it.

 

[Malleus]

Great suggestions. Thank you. I’ll do all of that.

As for the fuel filter, it’s brand new. Still replace? Massive PITA with the engine back in the truck from the looks of it.

If it's new, I wouldn't. Those filters are huge for US driving. They were meant for driving in areas where you have to strain fuel three times, before you put it into the tank.

 

[nagrom46]

Got it all back together. Same problem. Again, I removed the return from the FPR and no fuel.

I put 12V to the connector on top of the sending unit that serves the fuel pump and got nothing. Brand new Toyota pump on.

Hooked up 12 V directly to the old nasty pump and it runs.

Seems to me that the pins in the connector that attaches directly to the fuel pump maybe just need a cleaning. Pretty rusty and nasty looking in it. Had to scrub off the male pins on the old pump to get a good connection to get it to run.

Question though, does anybody know how to de-pin this connector? I’ve done most of them on the main engine harness and replaced with new, however, this one is a bit different and looks like it may be hard to source if I destroy it.

Or maybe I should be looking elsewhere for my issues?

 

[TheBussman]

yea that little piece of plastic with the "5" on it pops out and then you unlocks the tabs to de-pin it. i think your on the right track.

 

[nagrom46]

yea that little piece of plastic with the "5" on it pops out and then you unlocks the tabs to de-pin it. i think your on the right track.

appreciate that!

 

[DaviMH47]

I had the same issue after a rebuild but I had no spark. Ended up being the igniter box being loose and not grounded.

 

[alia176]

I don’t have a way to test the relay. Visual inspected and switched around fuses. Same result.

Put 12V to the fuel pump per the FSM, and got nothing. Pulled the pump and found this. Yikes. View attachment 3823488

This pic is making me ask why did that bracket get so corroded? The tank was empty but it's a closed system so the AR humidity shouldn't have been a huge factor. So, does this mean there was/is water in the tank?

 

[nagrom46]

This pic is making me ask why did that bracket get so corroded? The tank was empty but it's a closed system so the AR humidity shouldn't have been a huge factor. So, does this mean there was/is water in the tank?

I’m pretty sure this truck sat for a long time at one point in its life. Maybe had just a few gallons of gas in the tank while it sat and condensation occurred

 

[tech_dog]

1) Missed ground connection maybe?

2) What Nagrom said about old fuel.... I had to flush my boat tank twice after it sat for three years. The first flush wasn't enough and It plugged up the newly rebuilt carbs again. (yes, carbs.)

 

[alia176]

I’m pretty sure this truck sat for a long time at one point in its life. Maybe had just a few gallons of gas in the tank while it sat and condensation occurred

couple of years is a long time, and I can see how the rust occurred.

 

[bicycleagent003]

Okay, that fuel pump is straight out of a horror movie. You gotta warn us before you put up a photo like that! Yikes!

 

[nagrom46]

The problem was that connector. Got the pins cleaned up, tested it prior to installing back into the truck, and then installed the pump back in the truck and it fired up. Ran it for half hour so I’m confident that problem is solved.