cruise control losses speed

[Trana Rogne]

On the 91 v6 21 foot WB the cruise control looses it setting on a slight hill or a head wind, It will pick up speed if the throttle is taped. But it will slow down again. On flat ground it will NOT do this, the owners manual talks about this problem but gives no solution. Has anyone fixed this problem?

Trana

[motoyhomme]

The only people that I know that fixed this problem were the ones that installed a Chevy 350 V8 in the engine bay. Seriously, the Toyota engine is not powerful enough to have the reserve needed for the Cruise Control to respond fast enough to driving conditions/demands. That's why it's mentioned in the manual, so the owner is aware that it happens and is not a malfunction. I disconnected my Cruise Control as it was useless anyway on my 22R 4 banger.

Allen

[ILIA]

Odd. My cruise control that the previous owner installed himself has not once stopped functioning. Sure I live in flat Florida, but she has been up to Asheville, NC and back and the cruise control never stopped functioning. It's on a 22re and sure it has dropped up to 8mph, but she always has caught back up and adequately compensates with the right amount of throttle. Good luck

[Maineah]

Mine's worthless with a 22RE and if I used it, it probably would waste gas being flat to the floor all the time trying to catch up.

[Gulfstream Greg]

Make sure all the linkage is lubed and that there are no vacuum leaks. I can not remember how mine reacts so I can't comment if its normal or not but one would think once your back on level ground that it should catch up. In hilly areas and headwinds turn it off, its safer. Anyhow we are getting ready to take a trip and hopefully can report back tomorrow night how it reacted. We will be in terrain that is straight up and down, big hilly, slight hilly, freeway hilly, flat and of course down hill.

[Gulfstream Greg]

Well I tested it for about 20 miles through rolling hills at 60 mph plus or minus. Worked OK on little hills but what I found was the cruise control could not give enough throttle on the steeper hills. Dropping out of cruise control and manually giving it the gas would bring me right back up to 60 mph plus. Might be OK using it in Kansas with no headwind. And as a note at 60 mph the engine is running at 3500 rpm.

Hope that helps.

[Trana Rogne]

Well I tested it for about 20 miles through rolling hills at 60 mph plus or minus. Worked OK on little hills but what I found was the cruise control could not give enough throttle on the steeper hills. Dropping out of cruise control and manually giving it the gas would bring me right back up to 60 mph plus. Might be OK using it in Kansas with no headwind. And as a note at 60 mph the engine is running at 3500 rpm.

Hope that helps.

[Trana Rogne]

Thanks for the responses.

Apparently the system loses vacuum at high throttle settings, and can not keep the throttle setting. By blipping the throttle ( factory cure) more vacuum is created , and the cruise will resume it setting. It is a pain to keep blipping the throttle on a long trip. Turbo Volvo's use a vacuum pump to maintain the vacuum for cruise and other functions. see http://www.mwrench.com/barth/vacuum%20system/vacuum%20system.pdf

We will see if this fixes this.

Thanks

Trana

[Gulfstream Greg]

Thanks for the responses.

Apparently the system loses vacuum at high throttle settings, and can not keep the throttle setting. By blipping the throttle ( factory cure) more vacuum is created , and the cruise will resume it setting. It is a pain to keep blipping the throttle on a long trip. Turbo Volvo's use a vacuum pump to maintain the vacuum for cruise and other functions. see http://www.mwrench.c...um%20system.pdf

We will see if this fixes this.

Thanks

Trana

Turbo engines are different animals and really can not be compared to aspirated engines. Check all your hoses and cruise canister for a vacuum leak. Get a vacuum gauge and place a tee in the cruise line and see what its doing. I really think the cruise system can not give enough throttle (to the floor so to speak) with the weight we are pushing. I can maintain 60 plus mph on moderate hills with out cruise or overdrive. But use either and no-way, speed drops way down.

[seabreezer]

Hello,

Thought I would add my two cents as another point of reference.

When I drive my V6 Automatic Toyota Seabreeze at highway speed I use the overdrive and cruise control. I like to cruise at 62 MPH. On moderate inclines the cruise control will increase my speed to 65 MPH. As soon as I crest the hill, it will drop back down to 62 MPH. I'm impressed how well the cruise control will hold the correct speed on the downhill. I own newer,lighter vehicles that can't hold the speed near as well on the downhill.

On steeper grades, the moment the rig starts to struggle I try to turn off cruise and overdrive and let the tranny find the right gear for the job.

In my experience, if the cruise is in good working order it seems to work very well.

I might add that I live in the mountains of Northern Arizona where the elevations vary from 5000 FT to over 9000 FT. A whole lot of up and down driving.

Best of Luck on your repair,

seabreezer

[Maineah]

My 22RE cruse control is electric no vacuum but the bottom line is the 4 cyl. just does not have enough power to maintain cruse control speed and I think it is dicey with the 6 unless it pretty flat.

[idaho]

Mine has the same problem. If I set it at 65, it wall always fall back to about 55 even on the flats. Glad to know it's normal

[Tom W]

My works how well don't know, its a V6 I use the OD as much as possible and cut it off if its going to shift,with this much weight and wind resistance I would think the cruse would be hard on the trans(to much shifting), just my thoughts.