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Topic: Dead Throttle  (Read 714 times) previous topic - next topic

Dead Throttle

Just to satisfy curiosity I pulled the foot pedal to measure signal flow on the throttle position sensor under the pedal. On the accelerate prong it has a dead spot in current as you move the pedal from near half throttle to full throttle. After research found the sensor to be a Dodge diesel part and found one at ORiely. Will put it on this morning and hope that when I get back on the road Monday it will take full throttle. It would be to easy for it not to be the king box failing. I won't be suprised  either way but can't help but hope as I have 550 miles to drive back home. I've always had the "string kit" made up in case but I hope I don't have to drive home with it but can. Anyone who has had to drive by a string, what were the issues with the Allison shifting while fueling with a cord? I'll have more news Monday if the throttle sensor fixed the issue or was just one of two issues. You can't tell idling then rev because I had it doing that when I arrived Tuesday.
Dub McBride 1996 270

Re: Dead Throttle

Reply #1 –
Dub, did you check the new TPS to verify it changes all the way through?

What does the "String Kit" consists of?
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: Dead Throttle

Reply #2 –
Quote from: turbojack –
What does the "String Kit" consists of?
Driver runs a string/rope/wire/cable from throttle lever on the engine all the way up to driver seat.  Pull on rope to operate throttle.

Documented in several "classic" past threads on Forum.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Dead Throttle

Reply #3 –
Quote from: Dub –
Anyone who has had to drive by a string, what were the issues with the Allison shifting while fueling with a cord?

I seem to remember someone saying that it would not go into 6th gear until reaching governed rpm "flying by rope"

To be sure the brake light circuit can be 'seen' by the cruise / throttle control (which is the same circuit board) the controller must see a resistance through the brake light bulb to ground. If the brakes lights appear to be burned out or otherwise malfunctioning the King Control will only allow partial throttle control.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Dead Throttle

Reply #4 –
Be sure to block the bed up so there is no drag on the string.  Running the string through a 1' piece of scrap PVC works well.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Dead Throttle

Reply #5 –
Quote from: turbojack –
Dub, did you check the new TPS to verify it changes all the way through?

What does the "String Kit" consists of?
I'm about to check it and hope it has a continuous signal. Chuck described the cord kit and it will take you down the road which beats not getting down the road. Told Karen to have some sharp scissors ready so I can tie the string to a dash knob for cruise. Try to keep a sense of humor but the girl doesn't usually listen. I have a piece of pvc like you mention Bret.
Dub McBride 1996 270

Re: Dead Throttle

Reply #7 –
Tested the new TPS with ohm meter before install and the throttle pin shows no change in ohm when turning the throttle screw so it appears faulty. ORiely will have another new one at 3:00 today. Will see.
Dub McBride 1996 270

Re: Dead Throttle

Reply #8 –
When I the Monaco I sent the cruise control out for a rebuild and I wanted to keep skiing so I
made up a wire from the throttle to the engine and it worked fine. Shifting was off but it still
worked good enough to get me to Whistler and back. It's too bad Steve closed up shop as he
did a great job.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Dead Throttle

Reply #9 –
Interesting that 16 years ago the King Throttle workaround was being discussed. This link has some good info:

http://autos.groups.yahoo.com/group/foretravel/message/22132

Here is a broken throttle bracket that hope will not happen to others:

Broken throttle bracket repaired Cummins C8.3

We ran a wire from engine throttle through hole under the main breaker panel along floor to hand-made front wooden hinged throttle pedal. With wire slack removed, the driver controlled home-made throttle worked okay, but with some harsh transmission shifts. It got us moving for several days until more permanent repairs could be made. Running wire through the hole, kept wire along floor from front to back, keeping it out of the way when using coach.

King circuit board has a built-in throttle position sensor by creating variable voltages for the transmission control plug based on throttle movements.

Re: Dead Throttle

Reply #10 –
 :D  Francis's caveman cruise control!!!  I love it. 
Quote from: Doug W. –

2001 4010 U320 build #5865 "Bluto-d-Bus" since 09/18
2006 Honda Element ESP Toad
Full timing since 2016 in Western MT
Copilot: Sitka
1975 GMC 260 Avion: sold

Re: Dead Throttle

Reply #11 –
The second TPS sensor looks very similar but works backwards from the original. I'm out of luck until I get back home and not feeling real lucky then.It fuels fine sitting here at the park but who knows how long that last going down the road. My helper said when it fails, pull over, no choice with that, turn the key off then restart and that should reset the sensor. Fun is very limited on this trip for obvious reasons. I have the Mississippi River bridge to cross in Baton Rouge and that is not a place you want one to stall. I'll have the cord hooked up before I attempt that however good or bad this thing is pulling. No need in looking for another down here, on a weekend and leaving Monday one way or another..part number ORiely shows is TH 175 and I've had 2 of them that look similar but are different.
Dub McBride 1996 270

Re: Dead Throttle

Reply #12 –
I talked with Francis at Quartzite. He lost his King throttle in 22' and used a cable attached to a hand stick as described. He said without input from the tps built into the King it shifted at max rpm, therefore to reach sixth gear you had to accelerate up to about 70 mph for the shift from 5 to 6th. All the shifts were a tad hard going through the gears since Allinson shifted at max RPM. He runs his today with a tps mounted independent to the throttle bracket and the hand throttle. He did spend almost 50 years flying helicopters so he's used to such things.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: Dead Throttle

Reply #13 –
WOT is where I plan to start running anyway.... Like from now on.
Dub McBride 1996 270

Re: Dead Throttle

Reply #14 –
When I had the control out for repairs I made a bracket to tie the wire to the throttle peddle and
it worked fine. Just late rough shifting.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Dead Throttle

Reply #15 –
Reluctant to even bring up my hick up with what Walker family 7 is going thru but just an update. I could never find the correct TPS sensor in Biloxi or Gulf Port. The new parts look almost identical but my partner who is schooled in ohm resistance says the new ones would work backwards to what is on there. ORiely part TH175 shows to replace with.Left Biloxi this morning and drove 400 miles without a hitch as in full throttle. The bug is still there even though it was dormant today and the search for a replacement continues but will be much easier when the buss is in my shop and I'm home. I will post again when it looks like I have this bug licked but that will take a while. Hopefully it will help others with this same system for possibilities in the future. Saga to be continued.
Dub McBride 1996 270
 

Re: Dead Throttle

Reply #16 –
Stuff like this always helps the rest of us when it happens to us or just because we want to know what to do in case it does. Thanks for posting and hope you figure it out.
'99 U320 40 WTFE
Build #5462,
1500 Watts Solar 600 amp Victron lithium
2012 Jeep Grand Cherokee Overland Hemi
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Retired