You are not logged in or registered. Please login or register to use the full functionality of this board...

Williams air throttle
If the pressure at the actuator is changing smoothly but not the rod, it may be that the cylinder/piston interface is restricting movement.

If you have a restriction in the airline between the pedal and cylinder I believe you would see a linear relationship between the pressure at the cylinder and the rod position, but the pressure would rise and drop slowly.
Jon Kabbe
1993 coach 337 with Civic towed
I think Jon said it earlier, I'd try to connect a pressure gauge in the back to see if the pressure changes when you press the pedal. I planned to fix mine with a rebuild kit, I found the replacement before rebuilding it, plus my old unit did not look great to me. The seal/bellows had a couple holes in it. you can pull that unit off and pull the cover off where the air line connects.

Before I fixed my throttle I drove the Newell 200 miles from Indy to Jenison MI. When I pressed on the pedal it just wouldn't go. Even pressing the pedal down to the floor it took a while for the rpm's to increase. Driving home was an adventure - I got stuck on the side of the road a few times because of the lack of throttle function.
I thought it had to be something in the front pressure unit until after I replaced the rear unit. I couldn't find the front unit to buy so I guess I got lucky. I think the back unit was cheaper and easy to find on Ebay. Throttle works perfect now, which is awesome from where I was at first.
Your's sounds the same to me.
Mine is a 1975 and the old unit looked original to me so I just replaced it as part of my testing process and to prevent future issues.
Good luck - slow an steady always works for me.
Hang in there. Just my experience, hope it helps.

nice pictures - prices seem high tough -
John and Marcia Marshall 
1975 Newell 30ft - Diesel 9.0 IHC Navstar
Not pretty but will be.
98 Mustang GT - 05 Mercedes C Class
Amoco Dealer 78-97
Tool Designer - Master ASE Auto Tech - Systems Engineer IT
Marcia - Paralegal - Melco Embroidery part time business
Hope to retire - soon  Cool


Forum Jump:

Users browsing this thread: 1 Guest(s)