Jlg 40ha ??

[harveje]

newly acquired 40ha, born 12-90 and lived it's life outside, std controls, LPG/gas, 2wd. Long story short I made an offer and the guy took it so I had to tell the wife " Honey it's cheaper than me falling off a ladder"
I'm having a few issues and the great JLG diagrams are not much help due to I can't see the damn things...
1. On LPG- Very cold shouldered, hard to start, but once running she does good
2. Gas-- manual pump and solenoid are bad so I used a boat tank and an elec low pressure pump to try the engine and it floods like a beast and runs terrible--Carb rebuild?? if so where in world would I get a kit?
3. upper lift cylinder leaks, the manual does cover this and I found parts, not bracing the beast to pull the cylinder.
4. with ground control switch on the engine runs extremely high RPM, is this normal? In platform it idles down and when foot switch is depressed the idles raises, but in ground the engine screams, I'm guessing 3K+, I'll try to tach it somehow.
5. forward drive is messed up, pushing stick forward unit moves then at half way unit starts bucking and acting up, reverse is fine throughout range.
6. sometimes the unit swing does not work, is that tied the the off level circuit? If not it's prob electrical
I'm slowly learning the diagrams and trying to understand the circuitry but it's huge.
The wiring is 95% unmolested and looks good up to the basket where there's a few splices and sheaving missing.

Sorry about rambling on and Thanks for the help

 

[LTC1967]

Mine has a Carburetor Zenith Model 33 with electric Choke if yours Zenith go to there web site for the closest distributor to you http://www.zenithfuelsystems.com/contact.htm

 

[harveje]

Ok JLG fans.....Got the carb rebuilt, strapped a plastic boat tank on top of the old tank due to extreme rusty, put an elect pump inline with a filter and fired the gal up...Now she runs on propane or gas...Yeah..Now I need to set the speeds...Does NE1 know what the base idle in ground and platform needs to be? The manual says take wire 7 off to force high speed which is 3K then replace and adjust till 2.2K. When the unit starts up what should the RPM's be? Also she has the DIS ignition, is there a tach wire I can tap into? I bought a digital rpm meter and at idle it reads 8xx and by ear it sounds 2x that.
When I move her the engine boggs down some until I let up on the lever then RPM's catch back up, what would cause this?

Thanks a Mill....

 

[willie59]

Ford DIS engine, standard controls, you can set the idle RPM with the idle stop screw to whatever you feel good with, 800 RPM, 900, whatever feels good and the machine is happy with. Selecting platform and ground controls is different. When you select platform controls, no functions being operated, engine should be at idle RPM (stop screw adjustment).

When you step on the foot switch to work a function, the foot switch should send power to R13 idle/run relay, which sends power to terminal 1 of precision governor controller, that should give you your low speed 2200 RPM to operate a function. The only time you hit high engine speed is when you're driving the machine and select the Hi Engine toggle at platform, then you should get the 3000 RPM.

When you select ground controls, the ground control toggle sends power to R13 to give you power at terminal 1 of precision governor to throttle the engine to 2200 to be able to work functions from ground controls.

The engine lagging in throttle response could either be the throttle primer pump in carb not working or the gain adjustment screw inside the precision governor controller needs to be turned CW just slightly to give faster throttle response. If you turn the gain screw too far, you'll know it, the engine/throttle will start surging up and down.

Myself, I'm not a gas burner expert, don't know if there's a tach check on the ignition, I have a digital multimeter that has an induction spark plug wire clamp (like on a timing light) that sends input to the multimeter. Set multimeter on 4, 6, or 8 cyl engine to view engine RPM on multimeter.

 

[harveje]

Thank you, it's making sense now. When I first got her as soon as she started enging would rev close to full bore.. Thanks for the relay and governor pins, I will start checking the sequence and adjusting accordingly. After looking at a VGS411 pdf it looks like a yellow/blk or yellow/w wire out of the spark controller (12 wire) should be a tach signal, still need some verification..
Thanks,

 

[harveje]

ok, got the idle in platform position to around 800, foot sw depressed around 2K and surges some then levels out, and high engine switch on more than 2K, when switched to ground it jumps to around 2K. I'll pull governor control tomorrow and adjust per manual. Is it good for these machines to cold start on ground sw and go straight to 2K rpm? or do I need to start from platform? Forward control is still goofy, 0-40ish% smooth drive action, 40-100% jerky, bucking action, is there a pot or sweep in the assembly that may be dirty?
Hooked tach up to yellow / blk wire from spark controller and tach seems to be reading 1/2 the RPM and it's set on 4 cyl mode so it may be a POC
What is suppose to happen when the platform / ground switch in in the center? My engine dies and will not start unless I move selector sw.

Thank for the help.

 

[willie59]

Engine surging would be the gain trim pot inside precision governor needs a tweak CCW, and you don't have to turn it very much to make a difference.

It really doesn't matter if you start it from ground controls (hi rev) or platform controls (idle rev), as long as it starts ok either way, no worries.

Fwd control: PQ controller? How does it work in Reverse drive?

If the ground/platform select switch has a center position, it will kill the engine when it's in the center position, ignition is disconnected in the center.

Also, if you use gasoline with ethanol mix, be sure and use an ethanol stabilizer additive in the fuel, otherwise you'll have problems with that Zenith carb from the alcohol.

And when switching from gasoline to propane, or vice versa, always have the engine running, flip the fuel select switch to the center position, wait for engine to die, then flip the switch to the desired alternate fuel and start engine.

 

[harveje]

I'm assuming pq controller I'm in process of verifying. Reverse drive is smoother and varies up to max. Engine still Boggs but I need to set the rpms them re test. Only fwd drv is acting up. I've learned to use sea foam or other additives with this crappy fuel. What is the small controller looking board on the inside of the ground control panel that has a few pots on it?
I have almost everything working except rpms thru governor, horn, and tilt light. Need to change plugs, oil and filter in her next. O yea leaky tower up cylinder.
Thank you again for the help and info. Very much appreciated

 

[willie59]

That should be a PQ controller on that machine. Problem could be faulty potentiometer or circuit card on the controller, or a problem with the wiring. On proportional control machines with more than one PQ controller, you just swap them to see if the problem changes. Not an option on standard control machines since it only has one PQ controller. About all you can easily do is switch wires at terminals 16 and 21 at terminal strip in the platform. This will make the controller work opposite, fwd will now be rev, and vice versa, see if driving in reverse is now goofy, that would confirm a faulty controller. If it still has a problem going forward, problem in wiring somewhere.

A small circuit card with trim pots inside the lower control box is typically a mid range board for the throttle. What Precision Governor controller do you have, and E201 or E 301? How many terminals are on the Precision Governor controller?

 

[harveje]

Yes std controls,
The governor looks to be a 301 from the google searches, it has 8 terminals with 7 wires, #1 being 12+ and 7 being high speed circuit, I tapped the tach wire into #4 and it works but only showing 1/2 running RPM which I'm thinking the tach is screwy. I adjusted the gov this evening to specs, 800 idle, 2200 ground, 3000 high. Tomorrow I will check drive now that rpm's are set and fwd is still screwy I will swap the wires to see if problem follows. I know it's crazy and this thing will only be used around my place but stuff that doesn't work right drives me crazy

 

[willie59]

Well, if that is in fact a mid range board inside the lower control box, then JLG has done it again, done stuff that ain't on the diagrams for that machine, which isn't all that unusual. If I recall correctly, the E301 has multiple speed capabilities, no need for a mid range board. 8 terminals is for sure an E301 and not an E201. I'd have to know more about how that controller is wired up, and how it relates to that mid range board to advise how to adjust it, really hard for me to do without looking at it myself.

 

[harveje]

I rechecked the web and it's an identical match to the 301 (-) the aux 2 pot, I'll take a pic of the other board in a little. None of the original schematic with the machine show that additional board, from what I can tell.

 

[harveje]

here is the board, the brn/blu and brn/red to to terminal 16 and 21 which are the drive fwd and rev, the top blue goes to a Bosch relay, I switched 16 and 21 and the problem followed, jerking and bucking past 50%

 

[willie59]

I would wager you have a faulty PQ controller, but I can't confirm that, and it really sucks that it's a standard control machine with only one PQ controller. One option you have is to send your complete controller to Hindley Electronics and have them test the controller, they can tell you if it's faulty and supply necessary replacement parts, but be prepared, depending on which circuit card the controller uses you could easily spend in the 4 to $500 range.

As for that circuit card in the lower box, I'm baffled. That's a PWM to 12V amplification card that's typically used on the 100HX/110HX and 120HX, and it's definitely connected to the drive circuit with the brn/blu and brn/red wires. The yellow probably goes to ignition (power) circuit, and the brown is ground. What relay does the blue wire go to?

 

[willie59]

Another thought, can you post a pic of the drive controller at platform so I can confirm it's a PQ controller?

Also, the potentiometer on the circuit card of the controller, does it have three solder pin connections, or does it have four?

 

[harveje]

Thanks, 3 relays have pulled loose from the box and of course it goes to one of them, either creep or ign, don't know what the 3rd one is yet... On the drive mech it has PQ cast into the housing. I have not pulled the platform cover yet but will tomorrow to verify wiring. ? how hard is the gas tank to take out?

 

[willie59]

It looks like your wiring hasn't been butchered by a spaghetti mechanic, so concerning the relays that are popped loose from the moorings, the color code of the wire that goes to terminal 87 on the relay should indicate what the function is according to the wiring diagrams.

Yes, PQ cast onto the housing confirms it's a PQ controller. Let me know if the potentiometer on the controller circuit card has 3 pins or 4 pins.

Haven't pulled the fuel tank on one of those, not sure what would be involved with that.

 

[harveje]

Took platform cover off and here are the pics

 

[willie59]

Ok, it's worth a try because you might get lucky. That info on the side of potentiometer should tell how many ohm it is, 200, 300, 600, something like that, let's just say it's a 600 ohm. Cut off the heat shrink on the solder connections, burn the solder loose to disconnect the wires from the pot. Connect the leads of a multimeter to the center pin and the one to the left, you should see 300 ohm =/- with the lever in the center position. Move the lever slowly in both directions and monitor the sweep of the meter, it's best to use an analog meter, digital meters aren't stable enough for this test. Full movement of lever from one extreme to the other should show readings of roughly 0 to 600 on the meter, and the sweep of the meter should move steady, no drops or jumps.

Now move the multimeter lead that's connected to the left pin and move it to the right pin, do the same test. If the meter sweeps smooth through the range then the pot is good. If the needle jumps around, probably a faulty pot.

 

[harveje]

10-4... Those faulty pots will get you every time.....:drinkup

Thanks for the help..

Looks to be a type J
either 500 or 600 ohms