Greetings fellas, This is my first post and I am glad to have found the forum. I have a Clark G127 Model: GCS15 Built in 1990. We have owned this forklift for more about 14 years and it's been a good little tug for what we do. When we originally got this unit it was used and didn't have any problems for the first few months. After that it blew a headgasket that I discovered when it missed and did a compression check and found 1 cylinder at 60 psi. The others were in the 120's We took it to a well-known shop here and they returned it in the same condition after 2 months, and I made them take it back and fix it, well same thing it came back with the same blown headgasket. I got fed up and told my bosses I would go ahead and order the parts and replace the headgasket. After all it's just a little 1.6L Mitsubishi 4 cylinder and I was familiar with the 2.4L used in the trucks and the 1.6L turbo engine from the Dodge Colt. I took the head in to a machine shop I used for my car engines and had them resurface the head (they took less than .010" off), did a valve job on it and I got a new timing belt. To replace it as well since I was in there. I also did a tune up at the same time. After I got everything together it started up and ran like a champ. No problems at all. It would start right up and idle and run throughout the rpm range with out a hiccup. Fast forward several years later and I start getting a miss off idle, and it spits and sputters but will usually run well if you hold it to the floor, but part throttle it’s a bear to get this thing to do much. We can make it work, but it’s a pain in my side because I cannot figure out what is wrong. I replaced the plugs and wires, cap and rotor and to no avail, Compression is all within 10%. It has a Pertronix electronic ignition module and the spark will jump any gap on my tester I set. I have checked for vacuum leaks and have replaced any related vacuum hoses that needed it. So I ordered 2 things a regulator rebuild kit and a mixer rebuild kit. (CA55). I am a pretty busy guy and travel often so my boss decided to have someone come in and fix it. Well he replaced the entire regulator with a new one (now I don’t have the priming button) and he told my boss that the forklift was just cold and would run better once it warmed up. Now I know this machine since the day we had it and other than having for the transaxle to warm up a little to get it moving the engine ran like a champ seconds after start up if you had to. So they send in another guy to work on the thing and he just pokes around and doesn’t really do anything. Just said it was cold. (Here in Houston in the middle of summer). So I finally get some time and I remove the mixer and rebuild it and call Clark about a plate that originally had a check valve, but now it’s just a small orifice. They reassure me that it was a running change and it’ll work. I get it put back together and it runs the same no change. There really isn’t much to adjust on this thing but I do have the service manual (I do not have a CO meter) but I set it per the manual as far as I could. I have adjusted it all the way in and all the way out with very little change. I followed the steps for setting it with out using the CO meter and it runs but the same. I have been thinking that maybe the Ignition module might be bad, but it’s just really weird once in a blue moon it’ll run like a top but then when we say something it goes back to missing and sputtering. The coil has a strong spark, the ballast resistor checks out hot or cold, and I have even bypassed it for a few just to see. I am out of things to check. Any ideas? Thanks, Jeff
I assume it has an Impco vaporizer since it has an Impco CA55 carburetor? I'm not real crazy about the CA55, but it should work nevertheless. You stated you rebuilt the carb (mixer), did you check that the piston inside the air body moves up and down freely? I ran across one CA55 that the seal ring on the piston was causing excessive friction for piston movement. The piston seal was a split ring seal, I simply sliced of a tiny amount of the cross section of seal with a razor knife and it fixed it. Also, does it have a vacuum lock off on the propane line prior to vaporizer? Most vacuum lock off valves have a filter inside of them. If not, do you have an in-line filter where the hose comes from propane tank and meets the machine frame or counterweight?
The vaporizer is a Impco Model J. I did check for free movment of the piston when I reassembled it. It did come with a new piston, I thought or at least the split seal. I do have what I am pretty sure is a vacuum lockout as the lind from the bottle passes through this device with 2 bellows and a pipe that runs from one side to the other and a vacuum line that attaches to it. If I remove the vacuum line and plug it the engine will die in a matter of a minute or so. As for a filter the line runs from the tank through a machined aluminum block that has what looks like a tap on it with a large flat blade in the end. and this is bolted to the top above the radiator cover then passes to the lockout. My question is even if the filter is blocked why would it run at full throttle? I have even run it at top speed through the parking lot and at WOT it runs fine. I may take a look at that piston again maybe it has swelled some and is causing it to stick. Thanks for the reply, Jeff
Ok, I just got in there with the flashlight and watched the piston and it moves freely with no sticking. I started the engine and slowly started to rev the motor and as I watched the piston it moved with the slightest throttle input. I can vary it up and down and the piston moves smoothly. I then went from Idle to WOT and the piston moved all the way down and as the motor reached the governed speed the piston moved back up slightly and it maintained the governed RPM. It's almost like it has a dead miss on one of the cylinders at times then it may be 2 cylinders. If you are just cruising its a steady baaaaaaaaa pa baaaaa pa bapapabaaaaaa if that makes any sense. But at WOT it runs perfectly. I am not as familiar with Non gas engines, but I am competent with most any engines except diesels, they just have to be gas fed with fuel injection or carburetors. This one has me leaning to the ignition module being bad or maybe my coil. I have the service manual for this unit and it indicates that the engine originally came with points and I am aware of Pertronix through the performance engines I have worked on in the past. But I can’t find any reference to this unit that is in the distributor. I have checked the vacuum advance on this unit and it is working and I don’t really have instructions on the Module. I have moved it closer to the lobe and farther away with no change, so I moved it back to it’s original location. I’m just at a loss here. Jeff
The redneck way of checking if it's running lean is to run it without the air cleaner, which might make it run a tad leaner, and when it runs rough you use your hand to block 3/4 of the air intake, making your own choke of sorts. If it smooths out then it might be lean, weak spark can also fire smoother on a rich mix, I think, but then a weak spark is worst at full throttle, right? I have no idea if "choking" would have any affect on a propane unit or not? could maybe try an unlit hand torch to test?
I have used an unlit propane bottle in the past with a tube attached to check for vacuum leaks. I had the entire air cleaner assembly off when watching the piston in the mixer move and saw no change. I have also choked the engine by holding my hand over the end of the snorkel. And it still doesn't change the part throttle response. I'm thinking its got to be an ignition problem but without any info on the ign module pickup, I'm a little stumped. I've set points and even dual points, but not a pickup like this. Ford TFI and DIS systems, Honda and GM HEI I am very familiar with. This one not so much
Swap the coil out first? cheap and easy at least.
Any recommendation on a coil, preferably from an auto parts store?
Any coil you have lying around or can borrow from a running engine should work fine to test it. To buy a new one I would go solely off of the pertronix unit. It may be that the Pertronix will work with any stock coil, then you're back to any coil you want. It sounds like you know a lot more about ignition systems than I do, but I do know a bad coil can work when it wants to. Wouldn't hurt to take out the ignition module and clean up any connections either. I'd be buying a new module if the coil doesn't help.
I don't really have a coil that would work DIS coil and an HEI coil, might be able to get the coil from my 95’ Taurus to work I’m not driving it right now anyway. I'll check one of the parts store for one with a built in resistor and give it a try. I wouldn’t doubt that the coil and ign module would survive without the resistor, I have bypassed it before and nothing changed. Your right about coils being flaky I have had them take me to my house only to not work the next morning. I’ve had them heat up and stop working, I have had them internally sort and cause a weak spark. It’s probably pretty cheap anyway. I am not sure when the ignition module was installed but it has no markings on it other than Pertronix. I just looked up their website and they have an Igniter system for Mitsubishi distributor. I’ll have to find the part number and (verify it is a Mitsu dist.)see if I can get another one, but after I check on a coil. Looks like I am going to have to talk to my friend at Autozone since the website won’t let you look just at what you want only for a specific car, besides I’ll get to rummage through boxes of parts. All this will have to wait till I get back from GA. Jeff
Ok, So a little time has passed and I was able to buy a coil for a early 70's truck with a 250 straight 6. This is a brand new coil and needs to be used with a ballast resistor or resistor lead. I have a ballast resistor installed, and changed the coil. It started up ran "fine" no real change to the sputtering and I left out of town again. I got a call that they were unable to load a 400 Lb load onto the truck and had to have the thing floored all most all the time. It would not idle. I returned home the next day and checked everything over and found nothing wrong. I tried to start it and had a difficult time and once it was running it ran terrible I could barley make it run. I ended up just swapping the +/- thinking that maybe they were marked backwards, still the same. I re installed the old one and the thing ran just "fine". I had a guy in to replace the packing and wiper on the secondary cylinder and I quizzed him about it and other than spraying some carb and choke cleaner he adjusted what he called the power valve. This is located at the inlet of the mixer where the LPG comes in, and has an arrow on it. Normally the setting is pointed at the inlet. He moved it 180* from fully left to fully right and it made no difference at all. He stated that it should kill the engine but it does nothing. Today I turned the thing around thinking it is basically a ball valve and I have played with it and played with it and it changed nothing; Does anyone out there have anything on these mixers the book and the instructions are pretty vauge. Regards, Jeff
I honestly don't know what the deal is with this unit at this point. But to my knowledge, that "power valve" should not kill the engine when you turn it to full minus (-), it doesn't fully block the port when it's at full minus. It's more of a flow (volume) control valve. The way it's supposed to work, or be adjusted, is with the engine at WOT and the most load you can put on the engine, such as holding the mast tilt back and running over relief valve, turn steering wheel to stops and hold it there. With engine under load, adjust the valve toward (-) until engine RPM begins to drop, then move it slightly toward (+) until it runs smooth.
Fair enough. Here are a couple more clues I thought of. Why would the new coil not operate the engine properly? I noticed that blowing into the fuel line from the vaporizer and the carb was very restricted and did not seem to change with movment of the valve. is the adjustment range supposed to be 180* or more? I actually turned it several turns that's why I thought it was some type of ball valve. Thanks, Jeff
I have this same lift (GPS15) and have the same exact problem! When I bought mine it always ran rough the first few mins, then got going fine. One day it started to sound like it was running out of propane, so we shut it off and decided to call it a day. Next day get a new bottle on, and it's just spitting and sputtering. Couple days go by and I use it and it "kind of" works, like you said, on full throttle. I had Modern Equipment come out at for $400 to tell me nothing. I checked all my wires (had a loose one on the alternator I read someone else had a problem with), and just went over everything twice. It ran PERFECT!! So I goto the store to get a new plug wire since I thought maybe one was bad... back to running like crap. Either wire. Few days go by and repeat - ru Sorry for highjacking your thread, but I'm having the same problem and would like to get this solved too!
I just noticed that the bracket that holds the alternator is loose and allows a lottle movment of the dist. I am going to pull the Dist later on and see how the teeth look I am wondering if the teeth are worn plus the loose dist may be causing problems. I did notice that at part throttle that the timing mark would dance around a bit when I put a timing light on it.
The loose distributor sounds like a good bet, particularly if you can see it dance under a timing light.
Ain't saying it's your problem, but many years ago I had a 1965 VW Bug, one minute would run good, next minute missed and ran like crap, just to straighten up and run good again. Took it to a buddy of mine who was a bug mechanic, he was under the hood for quite a spell fiddling with this, trying that, until finally he let out a grrrrrr with a few other words, went to taking stuff loose and yanked the distributor out like Medusa's head. Popped in a brand new VW distributor (that he just happened to have) in it, purred like a kitten the rest of the time I owned that car. It was just a "let's try this" on his part, turned out the distributor must have been so worn out inside that the dwell was constantly changing. Just saying goofy stuff happens with spark engines.
Years ago I had a old Bobcat 630 with a 4 cylinder Wisconsin engine. I had the same issue that you describe. After MANY weeks of lost time and trying to find what the intermediate issue was. I finally found out my distributor was grounding out. I would replace the distributor and see what happens.
I'm pretty sure that's where I'm at with this. Had Modern come out today with their "Top Tech" - Not too much better than their low level tech other than he was able to test the pressure. So now, where do I get the distributor for this?? :Banghead
I believe I have found the source of the problem..... I went to Pertronix's website and downloaded an instruction manual for one that looked close. In the guide there was a troubleshooting section and it mentioned running rough or no start. I checked the battery and had a solid 12.8V and then went to check the infeed of the resistor and found that I only had 10.4V. The book mentioned that to test it to run a jumper wire between the input of the ballast resistor and the battery. I did that and it fired up and ran like a champ. No more sputtering, I am going to let it set over night and see if it works in the morning as well. Jeff
Why I dislike with a passion working on spark engines...just too damn many things can make them go crazy. Anytime I have someone ask me if I do work on cars (spark engines), my reply is "I'd rather pour diesel fuel on them and set them on fire!" :yup
You feel the same way about Spark controlled engines, as I do about CRT TV's. My background is in electronics and whenever someone asked if I worked on TV's I would say no (got shocked a couple of times). I'll work on about anything else but that doesn't seem to be a problem anymore since CRT TV's are obsolete. All I have worked on most of my life are spark engines, from Briggs/Stratton, through 2-4 cylinder motorcycle engines to car engines and performance engines (Forced induction, building and modifying parts). In all that time I have only run into this 1 other time and that was a GM HEI that the Ignition wire would work loose and I would have to reach in in and plug it back up. I have only worked on a couple Diesle engines and that was only to replace a electric pump on a Ford engine and a starter problem on a GM. Jeff
Intrigued to know whether you solved your problem JeffTx? Have recently come across some similar issues and wondered what worked for you. Thanks
garyd, i solved mine with new points and condenser and just making sure all of the wires and grounds were good. i have a source for the parts if you do need them - not sure if i can post links or not here.
It was low voltage at the coil. Earlier I mentioned I had 12.8V at the battery (I had the truck running for a while, shut it down and took a measurment at the battery). I turned on the ignition and only had 10.4 at the input to the ballast resistor. My temporary fix is still there (adding a relay and running a wire striaght to the battery), but it still runs as well as it had in the past. I still need to adjust the mixer a little and reset the timing (from 6* back to 5*) and then reset the idle. Other than that it's working well. no more real sputtering or anything. Note: this is not equiped with points, it has a pertronix ignition module (AKA: Electronic ignition). Jeff