Can you share the timing degrees? I have same issue and timing wants to be around 15 degrees btdc and idle is good but dies or very underpowered with any drive load.

Hi. I think my inching valve needs adjustment. Cat 50DSA Lift Truck. Lifts loads no problem. Runs nice. Slow to move forward or back when cold. Can't climb small inclines with load at best of times. No info on inching valve maintenance or repair in operation and maintenance manual. Can you tell me where it is and how I can adjust it? Thanks!

Trust me - it was all of your efforts that made it happen!!

D*mn- I lost that bet. I wouldda bet the house the inching spool was out of adjustment-have seen it a million times! Glad to hear it was nothing major- congrats mr mixit

yep yep... kudos to mrfixit for making the correct guess
that little voice in the back of my head was screaming at me telling me to mention timing but i wasnt listening at the time... DOH! hehe... i'm sure it would of come to me at some point though ;)

congrats zoran

Yes, the lift is now operating like new. I've taken all suggestions from ignition, mixer, wires, plugs, etc. However, all those repairs and replaced parts made a slight improvement. The true issue was the "timing was off". Got the timing corrected and now it takes inclines and loads as it should. Thank you all for the suggestions, especially Mr. Fixit

come back and let us know if adjusting the power trim on the mixer really made much difference and brought that engine back to life. I'm curious now, have never had many issues with that in the past myself.

Any updates?

The power valve is located on the fuel inlet to the mixer on the underside of the inlet is a rich/lean adjustment.....you rev the engine to full speed and put it into tilt bypass and adjust the power valve.....is best to do it with a CO gas analyzer but know not everyone has one........to clean just remove the mixer from the truck and remove the diaphragm from the top of it and spray a rag down with a good cleaning solvent and wipe out the inside of the mixer good and can use air to blow it out.

from your descriptions first things i would do is take pressure readings
if engine is not missing or skipping why tune it up?

- take compression check on cylinders
- take pressure readings on hydraulic system
- take pressure readings on transmission @ the control valve (clutch, main pressure, torque converter)

- make sure the inching pedal system is adjusted correctly.
- you may have more than one issue with this truck being it has 12000 hours on it. it could be worn out
- the clunking in the torque converter area might be a broken flex plate so check it closely, or it may just be a clutch pack sticking or hanging up and then freeing itself up as you rev the engine.

you will find out alot if you just run pressure checks
there are tests that test it at idle and at high rpm... there ARE expected pressures at either low and high rpm.

just follow the testing procedures in the manual, if it does not meet the required pressure ranges at the expected rpm's you have a problem that needs to be fixed.

Kevin

You're correct on engine and air mixer model.
Where is the valve adjustment on the mixer? Any suggestions for a product for cleaning the mixer ? Thx

New discovery.. I heard a very faint clunk from the torque converter at low idle (almost like it was hitting a loose torque bolt). It disappears as the RPM's increase.

Any thoughts??

I'm thinking it's a fuel/ignition system issue myself.....what is your idle RPM.....Waht RPM is it when you put the pedal to the floor in neutral with park brake on.....when you put the pedal to the floor and pull back on the tilt lever and put it into tilt bypass what is your RPM drop to?? I have seen trucks do this and was jut a simple power valve adjustment on the IMPCO 100 air mixer...this truck more than likely has the Mitsubishi 4G64 engine with an impco model J and IMPCO 100 air mixer....sounds like it is running on the lean side and starving for fuel under load.....also how clean is the air filter.....need both fuel AND air to make a correct fuel mixture....

I don't know your particular machine but I would do the following: make sure the trans fluid is up to full, pink in color- not brown & burnt.

I would then make sure the inching valve assy (on the trans) is adjusted correctly- sounds like the trans is slipping.

As I said' I'm not familiar with your machine, so maybe one of the brethren here could describe how it's done on this lift

The ignition and/or camshaft timing may be off.

Kevin,

I will get right on new spark plugs cap rotor and wires and clean out the Vaporizor....I will go thru both the fuel and ignition systems and post the results.

Thats correct, the engine lifts with no issues as long as I rev the engine. No miss, blog, or hesitation.

It also has no issues accelerating when climbing a grade forward or reverse... it will eventually climb the grade by inching along.

It lifts capacity weight with no problem as long as you rev the engine- the engine doesn't bog or miss, etc?

Having to rev the engine on newer units to lift any weight at all is common- older lifts had a different style of hyd. system which would easily lift weight at idle- now this is not the case.

As far as having trouble climbing a grade, I assume the engine is accelerating but the unit fails to move? If this is correct- does it have trouble in both forward & reverse?

when was the last time the truck had new spark plugs cap rotor and wires put on it? Or could be the Vaporizor is full of tar and gummed up starving you for fuel....I would go thru both the fuel and ignition and do a COMPLETE tuneup on both

Year 2000

Model # GC30K
LP

Serial # AT83C01249

hours 12,000