cruise control

[ellis93]

Ok I'm tired of it jerkin and snatchin. If the speedo drops 2mph it freaks and speeds up. Does anybody know how to fix this.

[1STGENFARMBOY]

Mine does this to.....from what i have heard it's a nice little perk of turnnin up the pump and doing some mods...

I hope i'm wrong and someone can come up with a fix... it's supper anoying.

Dar

[Richie O]

Yup, my 93 cruise worked fine before the big injectors and pump tune. It makes me sick if I turn it on. The cruise control can not control the throttle quick enough after you play with the pump so it pumps the pedal like an old quadrajet 4 barrel with no choke trying to start on a cold day.

[Tacoclaw]

I'm not sure exactly how they work, but if they're vacuum controlled, then perhaps a dedicated electric pump with large gauge hose going to the controller. A vacuum accumulator dedicated to the cruise diaphragm may be easier and just as effective, but having a more powerful vacuum source would be tough to beat.

[ahale2772]

not trying to be barbaric here BUT...the high idle lever setups that the early 89' and 90's came with works great if you take the safety stop off and set it on the highgway.... I use mine everymorning cruising at 65-70 (but thats at 4am with no traffic on the road)

[ellis93]

I've got a lead on what it might be cuasing this and when/if it works,I'll post up the info.

[Mark Nixon]

Put a vacuum chamber/amplifier between the cruise module and the vacuum supply.
This, in theory, should smooth out the module's reactions.
FWIW, the '92-'93 GASSER trucks have a vacuum chamber on the C/C module.

Also, adjusting the cable slightly tighter may help.

Mark.

[ellis93]

I've not made it to it yet but there is supposed to be a shaft in side the unit that rusts up and causes it to jerk the throttle instead of sliding smoothly.

[ellis93]

Ok ,I've done all I can figure to do and it STILL does it
A member here sent me this link : http://www.dieseltrucksite.com/showthread.php?t=134
Looked like it could have been the problem, wrong......not this old boy. Guess I'm not that lucky.
I pulled it all down looked at all of the little pins in side and seen nothing but clean, shiny metal.
So I saved a servo off of a jeep awhile back and put it on. SAME DANG THING. Herky Jerky, rip and snatch.
So this tells me its in another area. You all have any other thoughts, I'm fresh out

[Mark Nixon]

Have you checked for excessive slack in the speedo gear pieces at the tranny?

Mark.

[ellis93]

Mr Mark I just got done checking those pieces and was gonna post up what I found. As you've guessed there was an issue down there. Seems the 90 off of the gear and its housing decided to loosen up. I've just got done tightening it back up with alittle loctite bet money it doesn't happen again.
I'm gonna give it a try on the way home and see

[ellis93]

MUCH! MUCH! MUCH! MUCH! Better. It'll still gets down on the throttle some when pulling a hill but I can definitely handle that.

[ciamcoop]

Back when my cruise worked before I swapped in a 5 speed I moved my throttle linkage back to the outside hole on the pump lever. Seemed to help it work more smoothly. I miss cruise control.....

[Mark Nixon]

Ellis,
Well, at least in looking you found something that was loose and it works "better".

I'm getting to be a baby in my old(er) age, if it doesn't have cruise I try to figure out why.
The flatbed has cruise control now, chased that sucker from VSS to TPS and found that the major issue was the clockspring and the TPS was intermittent.
Replaced the clockspring and rigged a TPS from something else to get by for now.
Oh yeah, on mine, with the cruise on, the TPS would allow a slow, gradual increase in speed, sometimes.
It was irritating as hell because I could not find the cause, then the tps just quit altogether.
I rigged in what I have and now she's smooth as silk.

My recent acquisition, a V-10 round truck, has cruise and A/C, but non-power windows, even so it's nice enough for me.

Mark.

[Mark Nixon]

Back when my cruise worked before I swapped in a 5 speed I moved my throttle linkage back to the outside hole on the pump lever. Seemed to help it work more smoothly. I miss cruise control.....

Are you trying to use the stock auto ECM and wiring?

Assuming you haven't already, plug your TPS back in and move the adjustment on it about 1/4 of the way up and lock it down somehow.
I used one from a '92-'95 Dodge Magnum engine, I fashioned a wire to fit in the slot (yours has a hex nut) and adjusted until it shifted into overdrive at the minimum speed of around 35 mph.
I bent the wire around until I had a way to hold the TPS where it needed to stay.
It looks more like a hook that locks in one of the TPS hold down holes.

All you're trying to do is initiate the cruise feature, it may not even matter how high you set it, just so long as the TPS is reading.

I assume you have the TPS plugged in already, as your speedo won't work without it on the auto wiring harness, if that's what you are using.

Also, plug the old trans temp sensor into the wiring and tie it up somewhere, it also defeats cruise and O/D if it's not plugged in.

Mark.