First fo all I would like to acknowlwdge that the info availaible on this forum is top class and has been very helpfull in my install project.
I have just finished the installation and testing of Audiovox CCS 100 universal cruise on my 2006 Isuzu Panther (Asian) 2.6L turbo diesel van (sold in India as Chevy Tavera). There are a few issues that I would like to discuss here.
1. The tach sensor is housed in the FIP and gives approx 220hz at 700 rpm (idling engine). This I believe is on a higher side. Blue wire connected.
2. VSS input is rated at 5000 PPKM (aprox 8000PPM). Greu wire connected.
3. Program set for VSS and Tach.
4. I used a relay for ground and 12V on the purple wire, activated from brake and clutch switch. Vehicle is a manual transmission.
5. Being a turbo diesel, vacuum is created by a small pump mounted on the alternator shaft. I used a 1liter pvc canister as a reservoir.
6. Sensitivity set at medium.
All function and wiring checks performed and found OK.
On test drive , increased to about 85 KMPH (engine at 2300 rpm) in fifth gear, the cruise locked and worked like a dream. Carried all safety checks for disengaging by brake clutch and off switch, all worked well. Speed held dead steady on inclines, probably due to better torque characteristics of diesels
After re-engaging at 85KMPH raised speed by accel button. The speed increased smoothly but cruise disengaged at 90 KMPH. Any attempts to re-engage at speed above 90 kmph failed.
Engaged again at 85 KMPH and reduced speed using coast button, the speed reduced steadily and cruise disconnected at 80 KMPH and did not engage below this speed.
This gives me a working range of only 10 KMPH (80 ~ 90 KMPH) . I would like it to be 60 KMPH to 120 KMPH ( 37 ~ 75 MPH).
Any advise on above from the senior members will be greatly appreciated.
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Its always better to have it and not need it, rather than need it and not have it.
Gentlemen,
All the issues resolved.
Disconnected the blue wire from tach input and grounded as mentioned on various posts here on the forum.
Road test solved the issue of upper speed limit of 90 KMPH, tested upto 120 KMPH, no problem. It appears that a rogue signal above 90 from the tacho was causing the cruise to drop out.
The cruise however still refused to lock on below 80 KMPH. Decided to try a lower PPM setting of 5000 on the servo unit. Switch2 changed to off position.
The cruise now operates from 50 KMPH all the way up to 120 KMPH.
One item worth mentioning here is that on pressing resume from a lower speed setting of even 10 KMPH brings about an aggressive response from the cruise though not severe enough to be characterised as a surge. I will probably try the different sensitivity settings on my next outing.
Good day and thanks for reading,
bains
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Its always better to have it and not need it, rather than need it and not have it.
Good diagnosis work on getting your cruise working. I never use tach for the reasons you discovered. The cruises are too sensitive to spikes in the tach signal and cut the cruise off. Always better to just use VSS and install a clutch switch to disengage the cruise if necessary. As for the abrupt response to the throttle on resume, this has to do more with certain characteristics that vacuum cruises exhibit. While your vacuum reservoir keeps the cruise working well at most times, it also makes the cruise throttle changes seem very strong when accelerating or going up a steep hill. Try using a smaller reservoir. Cruises on manaual transmission vehicles are really only designed to used while in high gear. Most cruises are moving into electronic stepper motors, which are smoother in their operation and can be adjusted independant of the vehicle's motor. As a final tip, ensure that the cruise's throttle cable is tight with the engine off and has no slack in the cable. It should be tight, but not tight enough to increase the engine idle speed.
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sparky
Thanks Sparky for that info,
I am thinking to take the cruise one step further by installing a precision needle valve between the vacuum reservoir and the cruise actuator to fine tune the engage, resume and disengage response.
The slack on the cable is just about right at idle, bur when the vehicle is travelling at some throttle from the pedal, the cruise has to pickup thatmuch slack on its own cable before engaging and that is probably hapennig a bit quicker
Bains
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Its always better to have it and not need it, rather than need it and not have it.