Bugout4x4

I have a question about how to cure a Cruise Control issue. It is a 97 4.0 and everything is normal but noticed a quirk I would like to try and cure. Maybe someone else has tackled this issue?

I noticed that when I have the Cruise Control engaged it has a habit of doing a kind of "All on" or "All off" type of adjustment to maintain a set speed. I no longer use it because of this. I can get better fuel mileage if I manually "Float" the throttle myself.

Many Makes and Models I have worked on in the past were actually adjustable so that you could "Tune" it to be gentle and tactful to "float" the acceleration/ deceleration cycles rather than All on, All off like this one is doing.

Does anyone have any suggestions? Port the vacuum source maybe? Am I missing something on this system? any help on this would be great! I would like to use the Cruise and get the same mileage I can when manually feeding it.

Fred/N0AZZ

Sounds like its working to me like all the others, my 04 WJ and 12 Linclon Town Car work much smoother for sure. I think its the nature of the beast I'm just glad that it works, to hell with the mpg's.

Bugout4x4

I get you, lol. But it is kind of important for me, We live 150 mile round trip from the nearest Stores and Fuel Stations . I am getting about 26 MPG if I drive it manually and only get about 17 with the Cruise on. That's quite a difference!

We try to get back home with as much Fuel in the tank as possible so we can Wheel around here a bit and still make it back to Town. We try not to haul Fuel Cans if we can help it

I am going to try putting a port inline so that maybe the Vacuum volume might apply to the Diaphragm slower? Was hoping someone may have addressed this issue before.

Appreciate your reply Sir, please let me know if you think of something!

sycoglitch

question, where you are driving with cruise, are the roads smooth or hilly.

Bugout4x4

The 4.0 seems to have the torque to not feel much load until I hit a fairly good incline. But the Cruise seems to apply on and off pretty stiff the same hilly or flat. It is working correctly per OEM I'm pretty sure, just seems it is touchier than a lot of others I have used.

Be nice if it was a little gentler in application between acceleration and deceleration cycles. It seems to wait a little longer to apply acceleration than most, then it seems to stay in longer than it should causing it to have a stiffer than needed deceleration cycle to bring it back down.

Like I said it is all on or all off and the gap between cycles seems a bit too far apart? It actually "floated" smoother and gentler before I fixed the wide open broken Vacuum line to the Reservoir! lol

Any suggestions?

Fred/N0AZZ

I'm more interested in the 26 mpg that's the best I've ever heard of for an XJ. can you tell me more about yours?

sycoglitch

i used to get 24mpg stock on the highway according to the overhead display

sycoglitch

I may have missed it. Whats the build of your jeep. Tires lift etc. i wanna see if you need to adjust your TV cable

Bugout4x4

I haven't chased down the gear ratio yet but it is a "Sport" and I am thinking it was dialed in from the factory more for the Highway cruiser market. It has 235's on it and are two sizes over stock. It very well could have had a mileage ground Cam installed. Almost all my driving miles are steady on the highway. But mostly, I am very gentle on the feed and keep it around 65 consistently. I see no purpose in racing everyone to the next Red Light

I had to refill it twice and calculate it twice because I had trouble believing it too. Lol

Bugout4x4

It's a 97 Cherokee "Sport" with the 4.0. I did have to set the TV cable slightly when I first got it. Everything is good there, I would nice to be able to adjust the Cruise Cable though, It is designed static with no adjustments.

Forgot tire size sorry! Could it be just that I have 235-15 tires instead of the stock 215's ? I think the speedo is off but could the vehicle tell the difference in Tire diameters as to application gap of the cycles? Maybe it is also reading the "load" in application adjustment?