Loss of Power (1 Viewer)

[virafp]

Hi..need some help here. 2001 LC 100 with 230K.

Recently, on ocassion, when driving up hill the engine loses power. The first two times this happened, the fuel was below 1/4 tank. The last time it happened, the fuel was at 3/4.

Suddenly, pressing the gas pedal has no response, but the engine is still running. It lasts about 15 seconds, and then everything is OK again. No issues on start up. The third time it happened, my daughter was driving, and she pulled over, shut it off, restarted immediately, and all was OK.

Any help would be appreciated - no CEL or any other lights are on. I initially thought it may have something to do with fuel delivery on a low tank, but then it happened at 3/4 tank as well.

Any suggestions would be great.

Thanks

 

[2001LC]

Was she going up hill also?
What maintenance has be done recently & by whom?
Anything else going on?

 

[mrbigboy]

Reminds me of the TPS (Throttle position sensor) or APPS (accelerator pedal position sensor) issue that occurs frequently with older Dodge diesels. Might be a place to start. I haven't had this issue with the LC, but perhaps others that know more about this can chime in.

 

[virafp]

No work has been recently done except for new brakes on all 4 wheels. I Yes, it only happens going uphill. and normally when not at full operating temp.

I do not feel its the tranny, because its not like the engine revs stay up and the speed slows. Its the engine revs dropping and no response to throttle inputs.

Thinking of replacing the fuel filter and cleaning the MAF sensor as well.

Is this a warning sign for fuel pump issues?

 

[El Cid]

I am experienceing a similar issue, but the power loss is shorter and less dramatic. Not always on a hill. I've replaced the fuel filter and still have it. Yours may be something more pronounced.

I'm convinced it's the fuel pump and I intend to replace it, but I think the checklist approach of the other items mentioned above still has some validity as I won't know this was the problem until the fuel pump is in . I'm at 175k and probably need a new fuel pump regardless.

TPS (Throttle position sensor) or
APPS (accelerator pedal position sensor)
Fuel Filter
Fuel Pump.

This is a tough one to diagnose. I've taken it to a Land Cruiser knowledgable mechanic and still don't have a firm grasp as to the diagnosis.

 

[virafp]

I am experienceing a similar issue, but the power loss is shorter and less dramatic. Not always on a hill. I've replaced the fuel filter and still have it. Yours may be something more pronounced.

I'm convinced it's the fuel pump and I intend to replace it, but I think the checklist approach of the other items mentioned above still has some validity as I won't know this was the problem until the fuel pump is in . I'm at 175k and probably need a new fuel pump regardless.

TPS (Throttle position sensor) or
APPS (accelerator pedal position sensor)
Fuel Filter
Fuel Pump.

This is a tough one to diagnose. I've taken it to a Land Cruiser knowledgable mechanic and still don't have a firm grasp as to the diagnosis.

Yes, I am also inclined to think its the fuel pump as the next possibility. Two times it happened, the tank was below a quarter, so I wonder if its also gunk that is blocking pick up of fuel at low tank levels.

How easy is it to either clean or replave the fuel pump? I believe the pump also has a filter.

Just saw this as well...

TPS/APPS problems

 

[2001LC]

Are you giving it a lot of gas (pressing peddle)? What is RPM before, during and after?

Suddenly, pressing the gas pedal has no response, but the engine is still running. It lasts about 15 seconds, and then everything is OK again. ***

 

[virafp]

The RPM's are around 2200, not going too fast, probable 25-30 mph. As it happens if I push on the gas pedal, nothing happens. Then it all comes back to normal in 10 secs

 

[2001LC]

So RPM just holds at 2,200 RPM for 10 seconds! Assuming your rig is well maintained, and hill climb nor gas tank level had nothing to do with issue. Then it sounds like throttle body issue possibly TPS or APPS.

 

[virafp]

So the CEL came on today - that will give me a better idea when I check it tomorrow.

 

[mrbigboy]

Keep us posted on what you find.

 

[virafp]

Keep us posted on what you find.

So the code was P1074. I cleaned the MAF, reset the code, and so far no code and it seems to run smoother, so I am hoping that was the issue. Am also planning on changing the fuel filter, and having the fuel pump pressure tested.

 

[virafp]

So cleaned the MAF and cleared the code. Just finished a 600 mile road trip and all is good again! I love how simple our trucks are! And how great this forum is!

 

[virafp]

And we are back! So the last two days it has lost power on the same uphill, in almost exactly the same spot. Today, it stayed at 2000 rpm, but would not climb any higher. I dropped her into 2nd, and it still stayed at 2000 RPM. Got home, it had a code P0171, so I cleared the code. Disconected the battery, and now whe wont start! Cranks fine, feels like it wants to fire but does not. Thinking no fuel maybe?

Fuel Pump?

Any ideas?

 

[DiegoCrzr]

Clean MAF sensor

 

[ton504]

Sounds like a fuel issue. You won't get any codes that will point directly to fuel but it will give you lean codes you're getting. Denso pumps are cheap on amazon and are pretty easy to install. Remove the LH middle row seat and pull back the carpet, this will expose the access panel to the fuel pump. You will be able to hear the pump prime if it's still working.

 

[2001LC]

Quick test of fuel pump low pressure: Pinching the fuel return line, (Edited: Pinching could damage line!) this will increase fuel pressure. It's a rubber hose that is clipped/hung on the engine cover DS near fire wall.

 

[virafp]

Ok, so my hunch was correct. The fuel pump would switch off intermittently. 230K miles later, not too bad! New pump going in today.

 

[virafp]

Fuel pump replaced. The car feels totally different. I guess pumps lose pressure and then fail. because with teh new pump the performance is much better, especially on acceleration.

 

[El Cid]

Sorry I had not responded, I was busy.....replacing my fuel pump as well.

And that was the culprit. It is scary because you could be in the center lane of a five lane highway in rush our traffic but on the flip side it is a straightforward fix.

Immediately mine ran better and with the age of my engine it made sense.

Your power loss was more dramatic but I would tell anyone to just replace the filter and pump to be in the safe side. My challenge was my mechanic didn't believe me....it turns out I was correct originally but ok.

Relatively simple and safe part but it can leave you stranded.