Hesitation when hot and under load above 2000 rpm

[Therealtotodile]

Hi mud,
I was trying to get to the Kirkwood area to do some dirtbiking and encountered dome issues when I got to independence, driving from San Diego.

After about 300 very hot miles, the engine began hesitating under load. If I’m above 2k, it feel like power just dips, like it’s not getting fuel. Seems worse on inclines. I waited all night, and nothing yet this morning and I have been driving for a couple hours. The fact it’s intermittent. Makes me thinks it’s probably not a clog…. But!

The cats have an audible noise, and I know could be clogged. They have been destroyed the entire time I’ve owned the truck, over like 6 years.

The fact the car runs fine today after sitting all night in the cold mountain air, makes me think it is not fuel. Fuel system has been recently redone including filter sender and pump.

I also cannot find any vacuum issues.

Wanted to ask if anyone had other ideas, it’s Sunday, so I’m on. My own.


Best,
Chris morrissey

 

[OffRoadScott]

The hesitation could be several things. I would first check the fluid level of the transmission and make sure it is clean and filled properly.

When you say hesitating can you feel a miss or is it not shifting down? My assumptions is it could be your wiring harness near the EGR. This is a known issue with the LC as Toyota routed the harness close to the EGR and over time it does tend to melt and the wires could short out.

If it is not shifting down on the hills the kick down cable could be out of adjustment.

I would also check the resistance of the O2 sensors as well. They could be reading wrong and dumping fuel when extra fuel isn't need or vice versa. If I recall correctly per the FSM the O2 sensors are supposed to read between 5.5-6 ohms.

 

[tbasch1]

this is probably unrelated but I had a similar issue around 2000 where the power would dip and it would feel like it was bogging down and for me it happen to be a bad/loose sparkplug causing a miss and that resolved the issue for me

 

[alia176]

Chris,

Please check for vac leaks using a smoke tester. Looking at vac hoses yields not much data. A smoke tester pumps your air pathways with smoke then you see where it's leaking out of. If you don't have a CEL, start with the easy stuff. If you do have CEL (fault codes), then pull them and update your first post. Pls keep updating the first post with info rather than burying pertinent info in your thread.

 

[Lancy96]

MR. Morrissey.
I had this issue not too long ago. The truck is fine when cold, once up in operating temp. it'll start to hesitate. Thanks to the old thread here I decide to tackle the easy job by pulling out the throttle body as you can see in the pic. I don't have the issue no more. Good luck.

Acceleration hesitation

Here is a list of the order I diagnosed the problem in. No CEL and had a studder when under load between 1300-2000 RPM's and when engine was warm: -Did a drain and refill on the transmission (thought it was the transmission slipping) -Visual inspection on all vacuum hoses -Undid...

forum.ih8mud.com

 

[ozarkmud]

It could be the fuel pump filter sock. Does that seem possible?

 

[alia176]

It could be the fuel pump filter sock. Does that seem possible?

Fuel delivery issues on our old engines are always a possibility. Having a field pressure gauge stuck to the windshield while driving will help the driver understand what's happening. However, doing this little task is a little bit of a chore since we don't have convenient access to the fuel system for a gauge.