help diagnosing a problem: rig not starting easy

[hatchethead]

My 2004 LC100 has had trouble starting for the last few months. I'll turn the key and it will turn over (crank?) but not 'catch'. Sometimes the truck will start on the first attempt, but for a while it took two attempts. Lately, it's taken three. I replaced the fuel filter, hoping that would help, but there was no appreciable change in the truck's bad behavior.

Yesterday, the guy who was replacing a u-joint of four reported that he couldn't start the truck at all. Its tank was 3/8 full, according to the gauge. (I have no reason to doubt the gauge.) He told me that when the truck was parked on an include, front up, it wouldn't start. But when it was parked on an include, front down, it would.

it started when I went to pick it up, but wouldn't start 30 minutes later. I called my trusty mechanic. He asked some questions, told me to disconnect the mass airflow sensor (?) and try to start it. The truck didn't behave any differently, but it then threw those codes. He told me to put some gas in it and try again. I added about 5 gallons and it started right up. Then I drove it home. Nose up on my driveway incline, it took a couple attempts to restart it. Nose down on the same driveway, it took one try to start. At the gas station where I topped off the tank and the truck sat level it took two tried to start.

Today, it's starting up when parked nose down on an incline.

Is this a problem with the fuel pump or part of the fuel pump? My truck isn't throwing any codes that my ScanGuage is reporting, so I don't know how to diagnose this problem any better.

Thanks in advance for whatever advice you can share with me.

-- Jason

 

[Somniard]

I think your fuel pickup sock is clogged? The hill start stuff points to some stuff dislodging. is your fuel tank rusty?

 

[hatchethead]

I think your fuel pickup sock is clogged? The hill start stuff points to some stuff dislodging. is your fuel tank rusty?

Thanks for the reply to my post. I thought the hill start stuff was interesting. I don't know if my tank is rusty.

Do you think pulling the fuel pump and cleaning the sock is worth trying?

-- Jason

 

[Somniard]

Thanks for the reply to my post. I thought the hill start stuff was interesting. I don't know if my tank is rusty.

Do you think pulling the fuel pump and cleaning the sock is worth trying?

-- Jason

I'm no mechanic, but if it isn't too much trouble its definitely worth a look. If its clogged that would be very diagnostic

 

[TahoeZ]

Check valve in fuel pump; replace with new OEM. Possibly fuel pressure regulator.

 

[hatchethead]

Check valve in fuel pump; replace with new OEM. Possibly fuel pressure regulator.

Thanks for the reply. Can you recommend a source for an OEM pump that won't break the bank? PartsGeek, perhaps? PartSouk?

 

[Trunk Monkey]

You said it did have CEL codes, what were they?

 

[hatchethead]

You said it did have CEL codes, what were they?

No, that's one of the challenging things about this problem: no codes that my ScanGuage are showing. (My mechanic's advice to disconnect the air mass flow sensor generated two codes.). My fuel pump problem has not thrown any codes.

 

[OEMGUY0720]

Sounds like a fuel delivery issue. Could be fuel pump, fuel injector/s, spark plug/s and/or coil plugs. I would start by physically inspecting all of them for wear and eventually run functionality tests.

 

[Trunk Monkey]

At 200k+ miles, I'd go with fuel pump. Look for one of the SE dealers upcoming sales, there's a thread.

 

[hatchethead]

At 200k+ miles, I'd go with fuel pump. Look for one of the SE dealers upcoming sales, there's a thread.

Thanks for the advice. What are 'SE dealers' and where on ih8mud do I find these threads of which you speak?

 

[SmoothLC]

SE = Southeast Toyota dealers

See Latest Toyota/Lexus dealer sales and discounts

 

[hatchethead]

SE = Southeast Toyota dealers

See Latest Toyota/Lexus dealer sales and discounts

Bit the bullet and ordered Toyota pump from Decatur, online. Thanks for the recommendation.

 

[hatchethead]

Installed the new pump. Had to use the old filter. Oh, well.

The FSM has some info about testing a fuel pump, so I think I'm going to do that now that it's out. If it checks out OK, I'll put it in my cache of other Toyota parts-and-things. I hope it DOESN'T check out and that the new pump solves my problem.

Starting the truck with the new pump worked, but the truck behaved a bit like it did with the old pump: turn the key, turns over for a scant 2 seconds and then starts. Can someone tell me if this is normal, or would the starting happen faster if everything was hunky-dory?

(When my gas was low or if I was parked on an incline, it might take two tried to start. Or the truck might not start at all.)