Sometimes you just gotta have the laptop with the right program.

Had no lights flashing on the dash. Called up Great Lakes and sent in a tech with laptop, scanned system and found the 2 bad sensors.
Cost for the parts was approx...$180.00
Service call plus 2 hours approx.$210.00
Having an excellent technician...Priceless!

well thats good info to know michael
gotta love them hyster engineers that were thoughtful to think of that ;o)

cant say that about the mcfa engineers, we have to replace the complete throttle body if the sensor goes bad.... doh!

This particular 3.0 engine has a throttle position sensor mounted on the throttle body that can be replaced without replacing the whole throttle body. Yep, them sensors can cause strange problems.

cool beans bob......
woohoo! :o)

generally the TPS or PPS would throw a code or a flashing light on the dash though
You didnt mention anything about that, didnt notice it i guess ;o)

you replaced both units? the pedal position sensor AND the throttle position sensor (throttle body)?

yeesh... money money.... :oD

Yippie Ki Ya!! The unit is fixed. Ended up being the Throttle Position Sensor and the Foot Pedal Position Sensor.

Thank you for all the assistance.

Bob

When you replaced the radiator- did the engine overheat? I had a Toyota with a 3 L GM where heat was a problem. Had a intermitant shut off problem which turned out to be a bad coil pack.

First off i would like to thank everyone for the assistance. I am still pondering my issue. Let me go into a little more detail. S/N D187V31527B. Gave the Lift Truck a tune up 2 months ago, all was fine. We had a radiator issue. Installed NEW radiator. All is fine. A week or so later we started experiencing stall issues. Replaced LPG filter and vaporizer. No change in the operation. Removed carb cover and checked the diaphram, no holes, saw a couple weak areas. Did not replace. Found a leak at the intake/exhaust gasket. I don't know who did the repair on this but i found only 1/2 a gasket, someone cut the gasket ends off. The exhaust was gasketed with what looked to be Locktite 515. The repair lasted a few years. Replaced the gasket. No change to the stalling issue. :( That's where i'm at today. 3-30-2012 Going to do some electrical checks today, also checking sensors, "it's always a sensor issue" (Joke with the Mectron Engineering guys.) Thanks again folks.

Shannon Precision Fastener

i just thought of one other problem we had with the GM V6's a while back, the oil pressure sensor beside the distributor can cause engine shutdown or no start conditions. I've had to deal with this once or twice and the guys in the shop as well a few times.
More thoughts to ponder on ;o)

Hyster doesn't use anti-restart timer like the cat, on anything that I know of, but they do use a revolutionary switch which can do this also. It is mounted near the battery box. It must sense distributor rotation and can work intermittantly.

i believe meliftman is refering to what is called a "dashpot" or vacum deceleration valve located on the throttle linkage at the mixer body.
I'd also look into seeing if this truck has an antirestart timer on it, cat uses those and they have been problems in the past that cause issues such as this.

More thoughts to ponder ;o)

It could be the diaphram device thatr prevents the throttle from snapping shut on deceleration. On newer units, it is adjustable at the lever. Have to ponder on it for more.