High Torque Motor: Stutter or Whiplash, WTF?

[Dela]

That's why I would suggest the driving lesson first.

ITS is located under your floor mat, it's a pain to get to if your running boards are rust welded.

[KY Gun Geek]

Ok so the driving lesson did help.

I think some of the issue is that having your foot on the top edge of the pedal gives you leverage -making it easier to move the pedal, so when the initial kick happens and you let off (cuz u panic or cuz of the inertia of your foot), it doesn't go slower it shuts down completely. Momentum pushes the foot forward, and bang, another jerk, and so on. Hysteresis?

BTW we call this bump firing a gun, and it works really well on an AR with a light trigger (often when you least expect it if your aren't managing the trigger right). Someone even makes a stock to make it easier. But I digress.

I think the real issue is that when the motor is first started, it is at too high of a level (which causes the initial hop) - either the controller output is too high or as discussed above, the ITS is not adjusted right. Makes sense to me that a stock motor with lower torque might not hop 'cuz it doesn't have the guts. So maybe the right diagnosis is that the ITS is not adjusted correctly for a higher torque motor (or is this adjustment "absolute")?

So, I found Scotty's post re EZgo diagnostics, and have some questions. Part of the procedure is to activate the solenoid with the pedal, install a jumper, and then take some measurements on the controller connector.

Questions:
DOES THE CONNECTOR STAY ON THE CONTROLLER?

whats the diff between BL+ and B+


Thanks!

Below is a snip from the diagnostic instructions:

ITS - INDUCTIVE THROTTLE SENSOR


With the key switch ON - Forward direction selected - Push the Accelerator pedal just enough to activate the solenoid.

Install a "jumper wire" between the batteries BL+ post and the solenoid post with red wires attached.

AT THE SIX PIN CONNECTOR OF THE CONTROLLER
Place the (+) probe on the red wire terminal of the connector. If battery voltage is not present, the red wire between the solenoid and the six pin connector is faulty.

[Dela]

Originally Posted by KY Gun Geek

Ok so the driving lesson did help.

I think some of the issue is that having your foot on the top edge of the pedal gives you leverage -making it easier to move the pedal, so when the initial kick happens and you let off (cuz u panic or cuz of the inertia of your foot), it doesn't go slower it shuts down completely. Momentum pushes the foot forward, and bang, another jerk, and so on. Hysteresis?

What controller do you have? If an Alltrax all you have to do is watch and count the green lights as you activate. You should see 4 blinks for your ITs

[KY Gun Geek]

Stock controller

[Dela]

I'm gonna stick with my theory... not much you can do with a stock controller that will make a diff.



This keeps making me laugh though:

".... some siding taken off the house...."



Sounds like Dad's got a cart that the kids will stay off - I'd keep things as is

[KY Gun Geek]

A quick up date:

I got busy on the farm, as well as working on my other cart, and let this one sit for nearly a month (dutifully charging the batts 2 or 3x per week).

The ITS box got flooded so I had occasion to do a little more testing (http://www.buggiesgonewild.com/elect...tml#post791090).

The ITS box dried out, and now the cart behaves exactly the way it did (fast take offs, etc)

Scotty sent me a page from a manual re voltage tests on the ITS and I got 1.6v when the solenoid clicks in (spec is 1v +/- 0.3v) and 2.5v at full throttle (spec is 2.7v +/- 0.5v). Full reading appears at about 3/4 of the pedal travel.

So my diagnosis of this is that the ITS coming on a little hot causing the the high torque motor to come on hot and make the cart lurch. As discussed above, this causes the driver to chicken out and back of the throttle, causing another lurch and the foot going forward, reactivating the throttle, and starting the cycle again (telling you this is how you bump fire an AR).

The manual is pretty clear that if the ITS is out of these specs, it should be replaced. This one is out of spec on the low side. But just to confirm, any experience with this? I hate to throw $100+ parts at something and not be pretty sure it will fix the problem.

[HammyAbeer]

I have a high torque admiral that similar to the D&D

I kinda like popping a wheely on take off. Lets everyone know I mean business.

[yurtle]

Adjust the ITS plunger in accordance with the manual, located in the stickies.

[KY Gun Geek]

Originally Posted by KY Gun Geek

A quick up date:

So my diagnosis of this is that the ITS coming on a little hot causing the the high torque motor to come on hot and make the cart lurch.

So I was WRONG!

Well, sort of

At the urging of several pros (Scotty, D&D Motors, and a local cart shop) I switched the motors out - I'm now back to the stock. Cart does EXACTLY the same thing! Jump, stutter, etc when the solenoid clicks.

So I did a little fiddling with the ITS (goal was to get things into proper adjustment just as Yurtle suggested above). In the interest of testing limits, I took the little plunger (along with the collar that works the micro switch) completely off of the threaded rod. Guess what: when I turn the key on, the white lead on the ITS comes up to 1.6v and the motor starts running. (yeah, the cart was off the ground so no runaways)

This make any sense to you guys?

More data to support a bad ITS?

[scottyb]

The cart runs without the ITS installed ???
That's unique for an TXT.
Is the solenoid welded closed?