Hello, I have the exact same problem. The forklift starts to run well until it exceeds half of the accelerator pedal. That's when it starts to lose power but the engine accelerates well. I have changed the potenciometer, engine rpm sensor and it remains the same. I've found that translational solenoids lower the voltage when you do that. It does so both ways. It has changed all the filters and hydraulic oil. It does not fail on the console. If the belt is incorrectly synchronized, how does the LHC module detect it?

I was gonna suggest turbo failure

Do we know what engine code it is?

you say timing jumped 3 teeth in that VW engine?

well you better be checking the valves in the head then
those engines had almost zero tolerance in the head and valve train and if the timing got off any at all there was valve damage pretty much 100% of the time.

if and i mean IF that engine is running well it wont be for long
we've done too many of these in our shop to know better than to assume everything is ok inside it after something like that

in the USA you can buy parts individually, we normally replace them at the same time.

Per the service records it was replaced few years but we weren't maintaining the unit at the time it was supposedly replaced.

we replaced belt, tensioner and waterpump for piece of mind.

Was tensioner replaced at same time when the timing belt was replaced?

Over here in UK they come as a kit, can't get timing belt on its own.

Problem solved. Timing belt tensioner failed & became loose and belt jumped ~3 teeth.(last timing belt was 1800 Hrs) ECU was putting LHC in to a limp mode due to low vacuum & running rich at higher rpms but would not throw a code. Its hard to believe a truck would start nearly instantly and rev up could be 3 teeth off. Thanks for all the help guys

I would replace the accelerator potentiometer as well as the 2 plastic gears. If there is ANY play in the gears it will cause this problem plus the gears are really inexpensive.

Yes, this is definitely an electronics problem. Faulty hydrostatic transmission (usually the internal leakages caused by some strictly mechanical defects) would reduce/disable the traction at any speed.

Its very rare for a newer design Linde hydrostatic transmission to give any trouble, in the 5+ years I've been looking after a fleet of 392 & 394 Linde's we haven't had any issues with the hydrostatic transmission at all.

Only things that have actually failed so far on the fleet & caused a breakdown are:

Brake micro switch x 2
Coolant reservoirs x 3
Gas shut of valve x 1
Throttle pot x 3
Inner rear hub bearing x 1
Parking brake **** interlock spring x 2
Parking brake actuator lever x 1

Plus a loose starter motor cable connection.

The newer family of Linde IC counter balance's is the best you can get in Europe, there very well designed, there built to last & there easy to service / repair when needed.

It sounds like your local Linde dealer need's to invest in some training OR get someone else with experience to look at this truck.
If you don't know your way around Pathfinder you can really mess the truck settings up & causes all sorts of problems.

supposedly, Hes from the Local Linde Dealer (The Largest One in the US) He seemed uncomfortable operating the pathfinder software last time when he diagnosed the bad hydrostat. which we replaced and didnt solve our issue. He mentioned he felt like he needed more training

A replacement pot needs to be calibrated with Pathfinder.

Also its very easy to fit the pot incorrectly if you don't have experience at changing them, the little tab needs to be perfectly aligned when fitting - I've seen this happen before a couple of times when I've been called to look at a Linde.

Is this an official Linde trained engineer with Pathfinder coming back to look at it?

waiting on the dealer to show back up we replaced the pot , it didn't resolve the problem either

I've replaced a few throttle pot's on Linde 392's, they never seem to throw an error but the poor performance of the throttle can normally be caught with Pathfinder by watching the voltage trace.

Last one I did the truck had lost top end traction performance, no errors showing but with Pathfinder you could see the pot was faulty, even recalibrating the pot didn't fix it.

New pot cured it.

How about the errors shown on Pathfinder (Linde Diagnostic Software) I understand, the disgnostics with the computer has been done by Linde service.

By the way, the fwd and rev selenoids are activated by the proper power not voltage.
You may check it with diagnostic software.
The wheels should start to rotate at circa 440/460 mA.
With the fully depressed acc pedal the value should be about 1220 mA.
The desired traction wheels speed should be ~ 200 rpm.

Generally, in my opinion, you may have problems with the traction pot. Even the calibration itself may not be enough. The pot may be anyway dead.Possible is the problem with the gear or pinion gear linked with the pot.

Still - it's all speculation. Yo can get the answers simply asking the dealer service (I understand it's Linde) for some serious computer diagnostics.

Max engine rpm is set to 2700RPM
Both Speed Sensors Has been replaced. the linde speed sensor looks to been defective or was going bad. The engine revs smooth and easier now but does not solve our issue. The VW engine speed sensor made no difference

There is no error codes shown on the display at all.

Good remarks, duodeluxe

I'ld ask additionally if there are no error codes on display or in Pathfinder? I understand Linde dealer service connected the laptop to the truck? If there are issues with the traction electronics, the Pathfinder should identify them.

I would stop replacing parts and check for simple things like the pedal stops.
Was the truck ordered with reduced travel speed?
What is the maximum engine RPM?
What is the serial # of the truck?
There are two engine speed sensors, one is Linde and the other is VW. Have you checked them?