Discussion:
Cat GC25K Fuel problem

Ok I am a car mechanic and new to the LP fuel system. Motor would crank but not start and now after many many hours I have removed the top of the carb and diaphram. the throttle plate was completey closed and the electronic throttle would not make it open. I put a screw driver in the carb to prop open the plate and shot a little starting fluid down it and it fired right up. Any ideas???
  • Posted 26 Mar 2011 05:08
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
Showing items 21 - 32 of 32 results.
not a chevy man myself but sounds like a wet ecu or cap. Try covering each item one at a time with celaphane to try and isolate the problem.
  • Posted 28 Mar 2011 04:20
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
You might have to crank the engine and step on the accel.to see if the butterfly opens. Additionally, as I remember, there were 2 or 3 wires spliced on neg coil.
I'll send you over some info to your email, but this is not rocket science it should not be to difficult to find.

You did say you are a car machanic, I have an issue w/ one of our chevy vans. V-6 vortec chevy 2000 express will not start Monday morning, when it rains durning the week end, truck is outside. Tuesday morning, starts fine w/ 24 hours of drying time.
Got spark and fuel, book says weak spark is like no spark( it dont look weak to me, but may when damp its just below level).
Any ideas? Was told to look at the fire wall connector or spark making componet.
Thank you
  • Posted 27 Mar 2011 20:40
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
What type of signal should be going to coil, voltage?
it appears the wiring has been spliced several times and neg from coil and dist are tied together. throttle plate will not operate at all with the key on and accel pot has tested ok.
  • Posted 27 Mar 2011 00:53
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
If it runs w/ start fluid then you have spark.
1st check to see you have fuel to lock valve and after lock valve.

2nd check if throttle butterfly opens w/ key on. If not then you have an electrical issue w/ ECU, accel pot, or wiring ect

3rd, if 1st 2 checks ok, then the problem is more than likly in the carb diaphram, (it pulls the fuel in from the convertor), or the convertor is no good.

make sure #1 wire on the ECU, tack signal, goes to neg coil.

If after you done all these checks and still have a problem, I will email some trouble shoot info.

The weather is warming, The Spartan Warrior is now leaving to go skydiving
  • Posted 27 Mar 2011 00:47
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
ed@shopteks (dot) com
  • Posted 27 Mar 2011 00:23
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
If anyone might have a troubleshooting guide my email is [email address removed]
Thanks!!!
  • Posted 27 Mar 2011 00:22
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
SER#at82d90348
electric Coleman carb
  • Posted 27 Mar 2011 00:18
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States
John, thanks for the recommendation (head swells)[especially coming from someone I think actually knows the difference]. BUT I do prefer that I answer on the forum, so that it is Google search-able and someone else with the same problem may benefit from the answer at some later point in time.
I DO try and give other folks a chance to answer some of these posts, if they want to, it is not my intent to monopolize the conversation.
I agree with everything 7777 offers up and while a serial number often helps, the description of the carb is good enough so that I know this is a tier 1 (2003) forklift at82d serial number series. (so it would be the electric lockoff) and of course, the first steps in troubleshooting an IC unit is (still, with or without computer controls) to find out if it has spark and/or fuel getting to the combustion chamber.
In this case, I would first recommend that you do NOT test the red and white wires at the vacuum control valve (mounted on a bracket on top of the regulator) as they are a pulsed signal to ground, and testing them with a test light or a meter may have just the circuit to let the smoke out of the ECU and then you would have the problem you describe as soon as the smoke clears.
I would also ask that 7777 and ed_h consider adding their e-mail addresses to their -profile-, so if someone wanted to send them something via e-mail, it would be possible to copy-paste a properly formated address.
When ed_h says "shot a little starting fluid down it and it fired right up" does he mean it ran until the starting fluid/fuel was used up, or it kept running until the key was turned off?
Has anyone messed with the accelerator pot? if so, it may have to be set using the computer program to set both the high and low sides of the pot, as this unit will not send a signal to turn on the fuel lock off or to open the throttle butterfly if the pot is too far out of normal setting, or has not been set up properly. also, has anyone pushed down on the accelerator pedal linkage without the floorboard installed? since that can also cause the ECU to consider it a problem with the pot reading being too far out of setting and may shut down the engine.
ALSO on this unit, there is what looks like a cable lug on the manifold mounting stud, that has 2 black wires into it. this is NOT a wire lug, it is a sensor for the engine temp to the ECU and putting those 2 wires together can cause this unit to not start (the ECU will consider the engine to be overheated to the second stage and shut it down).
These also do have a rod/valve in the lock-off/filter assembly that can get stuck and prevent fuel from flowing into the regulator, that I think was what 7777 was getting to when he mentioned "there are easier ways to check".
7777 used a blocked word where his post shows "****" and that word rhymes with truck, starts with the letter s, has 4 letters (or 5, if plural, as used here) and means "to draw a vacuum like we do through a straw".
  • Posted 27 Mar 2011 00:08
  • Modified 27 Mar 2011 21:50 by poster
  • By edward_t
  • joined 5 Mar'08 - 2,334 messages
  • South Carolina, United States
"it's not rocket surgery"
If you used a screw driver to open the carb, you probably have an elec. controlled carb. The carb is contrlled (to the best of memory) by a variable pot on the accelerator, and by an ECU (small black box w/ 12 wires). Be sure #1 wire is tied to neg. coil. You should see the carb. operate w/ the key on, when depressing the accelerator. If that operates, then your just not getting fuel.
Follow the fuel line from the tank to the 1st valve. Is it elec. or vacuum operated?. If elec. check to see if the soliniod operates and allows the fuel to flow. Remove it supply powr, and see if you can blow through it ( there are easier ways to check it).
If vaccum oper. there is a small vaccum hose that operates the valve and allows flow, check that.
Next is the convertor, the diaphram on the carb actually *** fuel from the convertor( the convertor has an input line at the top, 2 water lines in the middle, and 2 lower pressue fuel lines on the bottom, one is plugged)
Note: LPG fuel is pressured at 300lbs, is -40 degrees be careful.
Sometimes our customers get a bad fuel tank. when they replace tanks, a black quad ring comes out of 1 tank lodges inside the screw coupler, and wont allow fuel to flow from the new tank.
I also have some trouble shoot info.
J_CFORKLIFT@YAHOO (DOT) COM

THE SPARTAN WARRIOR
  • Posted 26 Mar 2011 21:37
  • By 7777
  • joined 8 Mar'11 - 649 messages
  • New York, United States
Maybe it is the vaporisator that doesn't let the gaz to the carburetor. Is your vacuum ok, no cracked hoses?
  • Posted 26 Mar 2011 12:45
  • By Dwaive
  • joined 7 Aug'09 - 33 messages
  • Quebec, Canada
I can't help other than let you know there is a guy on the forum edward t in north carolina who is very familiar with cat/mitsubishi lifts & very helpful to techs. His email address is in his forkliftaction profile. Surf around and find his name then double click on his name and it should pop up - send him an e-mail. Give him the make, model & serial number of the lift truck in your message - he will always ask for it. s/n on forklifts are important as the build dates on automobiles.
  • Posted 26 Mar 2011 06:22
  • By johnr_j
  • joined 3 Jun'06 - 1,452 messages
  • Georgia, United States
"Have An Exceptional Day!"
It is a 2002 Cat GC25k lift with a Mit 4g64 motor, Impco Cobra Yellow dot regulator and coleman carb with 2 red wires. if that helps.
  • Posted 26 Mar 2011 05:25
  • By ed_h
  • joined 26 Mar'11 - 13 messages
  • Georgia, United States

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