97 LX450 Struggles to Accelerate After Startup (1 Viewer)

[Lextronix]

The fuel pressure resistor has a male plug so you can jump the female(main harness) side with a paperclip or something more elegant.

The fuel pressure resistor provides for two speeds for the fuel pump...I think. Wide open during starting or high load and "normal" once at standard operating temps. I don't think there are any cons to running the fuel pump full bore in the near to medium term and likely none in the long term so its an easy and relatively risk free test.

I am dealing with a slight stumble at idle which I think may be a fuel delivery issue so I follow any thread some what related to the topic. I don't think your issue is well trod territory despite the insistence from others to search rather than spend. So thanks for posting!

 

[BILT4ME]

^He wont have a viscous coupler.

Why won't he have a VC?

 

[Lextronix]

Looks like I goofed, I'll go visit that search button.

Edit: I'd like to delete that but hopefully people will come to the second page and see me eat my humble pie.

 

[alia176]

Never heard of this. Is the a write up available? Also sounds like a good way to test.

Hey bud,

Look at the pic on post #12, see where the finger is at? Pull that vac hose off then cap it. Done and done. Your FPR is now bypassed!

Given the fact that you have no CEL on, it *feels* like your issue is strictly mechanical. As in, your ECU has no clue that something is amiss. You have to push your gas pedal all the way down for the vehicle to move AND you hear no funky clonking, squeaks or any other sounds tells me that this could be a mechanical issue but nothing is actually broke!

Since you have no Viscous coupler (did you remove it?), then we need to rule out your transmission slipping. You have a new to you TC so the tranny was dropped and my mind is going there. Your vehicle drove fine after this project so we can rule out poor electrical connections at the top of the tranny.

If you can engage your CDL and move the 80 then it's in the Tcase or something but this wasn't touched, or was it?

Oh, please update your first post with the pertinent info listed below. Also, update the first post with any info that may help us help you, rather than having to read bunch of posts . I'm sure more info will come to your mind that'll help your cause.



As for recent work, Jeez... Had the tranny out to do the rear main. Guide button thing on the torque converter was broken and missing and had to source a used one from a buddy. Went back together and ran like a top. Went on a 3day glamping trip in the NE Georgia Mountains and the truck basically s*** the bed on the trail. Short version there is that t

 

[BILT4ME]

After reading the post from @alia176 , I went back and re-read your posts.

He may be onto something here, but we need some clarity.

Can you place the transfer case into Low Range and will the CDL Lock light come on?
If so and the light comes on, does the truck still rev real high before it takes off?

When the engine revs, is it running poorly?

 

[bonestock]

After reading the post from @alia176 , I went back and re-read your posts.

He may be onto something here, but we need some clarity.

Can you place the transfer case into Low Range and will the CDL Lock light come on?
If so and the light comes on, does the truck still rev real high before it takes off?

When the engine revs, is it running poorly?

Truck shifts into LOW and the CDL sand ABS lights both come on. Truck does not rev real high before taking off.

It really only runs poorly after start up and the initial getting underway, especially up hill.

 

[b4kwav]

Mine was tranny solenoids but I have a 94

 

[Ghostrider I]

Why not replace the fuel filter?!?~!??!?!??!!?!?

 

[BILT4ME]

Truck shifts into LOW and the CDL sand ABS lights both come on. Truck does not rev real high before taking off.

It really only runs poorly after start up and the initial getting underway, especially up hill.

So, the "lurching and driveability" clears up when placing it it LO?

The engine still runs poorly, but it moves like it's supposed to?

 

[bonestock]

The lurching and drivability does not present itself in LO, at least that I am able to perceive. Another tidbit, the lurching and drivability does not always occur and not always to the same level of severity.

 

[BILT4ME]

The lurching and drivability does not present itself in LO, at least that I am able to perceive. Another tidbit, the lurching and drivability does not always occur and not always to the same level of severity.

OK.

Place the truck in LO so the CDL and ABS lights come on, then shut off the truck.

Then pull the 30A DIFF fuse in the lower right of the fuse block by your knee in the cab.

Then shift the transfer case back to HI and start the truck. This will keep the CDL locked until the fuse is placed back in. If this eliminates the driveablity and lurching, then you may have stripped front drive flanges.

 

[bonestock]

Why not replace the fuel filter?!?~!??!?!??!!?!?

Fuel filter is less than 3 months old and the sick and the fuel pump was relatively clean.

 

[alia176]

OK.

Place the truck in LO so the CDL and ABS lights come on, then shut off the truck.

Then pull the 30A DIFF fuse in the lower right of the fuse block by your knee in the cab.

Then shift the transfer case back to HI and start the truck. This will keep the CDL locked until the fuse is placed back in. If this eliminates the driveablity and lurching, then you may have stripped front drive flanges.

Great plan

 

[bonestock]

I have the CDL switch (7 pin mod I believe it is called). Can I just use that?

 

[alia176]

I have the CDL switch (7 pin mod I believe it is called). Can I just use that?

Yes sir, make it so #1.

 

[bonestock]

Doing it in the high side with the both the CDL engaged and disengaged. Can I pull a flange off to confirm?

Edit: now I am pulling a familiar 301 code.

 

[BILT4ME]

Doing it in the high side with the both the CDL engaged and disengaged. Can I pull a flange off to confirm?

Edit: now I am pulling a familiar 301 code.

It's hesitating both with and without the CDL engaged?
It will only move if you rev high?

 

[bonestock]

It's hesitating both with and without the CDL engaged?
It will only move if you rev high?

It was hesitating with and without the CDL engaged. High rev is relative I guess. Currently, I can just kind of baby the throttle for a couple minutes and it seems to clear up. Sometimes, it seems that trying to do anything other than 100% throttle will make it hesitate/bog down. It's hard to say because there are some many different scenarios and circumstances. I really do appreciate your trying to shepherd me through this though!

 

[alia176]

Maybe do a video then upload it to YT?

 

[BILT4ME]

Maybe do a video then upload it to YT?

Exactly what I was going to say!