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Cruise control re 91XJ 4.0L w/AT

Don Becker

NAXJA Forum User
Ever since we've owned the 91, the cruise has not worked. I have been aware the vacuum line to the servo is not hooked-up to anything. I cannot find where it is supposed to be connected . . . I've looked everywhere and there does not seem to be a fitting without a hose attached to it. And, the engine does not act as though it had a vacuum leak. Maybe one of you could take a look at your 91 and post a digital photo of where it hooks into the engine/vacuum lines/whatever. I did try just putting a tee connector into one of the lines and giving it a source of vacuum . . . but, that didn't work ............................ and, I realize that there could very well be another problem. I'd just like to see if hooking this line up to the correct vacuum source does any good before I ask my mechanic to go to the next phase. TIA! Don
OK, I'll try. The basics are check the entire vacuum system for leaks, especially the hose under the battery and the blimp in the front bumper. Then check the electric side- there should be poer to the switch in one of the wires going to it (ignition on). There should be power in additional wires with the cruise on and with the 'choose speed' button in. Common problem is broken wires that go to the switch, inside the steering column. Someone reported that the switch arm is a GM type available from the "Help" line at the car parts chain-stores. Try searching "cruise", there have been a few posts recently (better than my memory!). 4XBob
I can't send you the pic right now but I can tell you that the vacuum line from the servo connects to the T-connection on the vacuum-line coming from the vacuum reservoir mounted on the front bumper. That v-line should pass right under the servo bracket.... toward the firewall and ultimately connects to the intake manifold on the other side. The t-connection should be right in front of the servo mounting bracket---the v-line passes right under it.

If is not a vacuum problem, verify if the cable from the servo is connected to the throttle body.....

Damn... there's two pages of flowcharts in the SM indicating a slew of things that can go wrong.... ranging from electrical to mechanical.... including the engine controller.

If you get the vacuum line connected and it still doesn't work, next week I'll send you a pdf of the "Speed Control" pages from the SM.

FYI --- About ten years ago my '91XJ speed control stopped working.... it was the switch on the turn signal lever... dealer replaced the entire lever.. it's worked ever since.

Good luck
Thanks! That definitely gives me a start. I thought the Tee or Y connector would be found on the left side. I'll check this out. I realize this may not be the only problem . . . but finding the correct place to connect this line certainly seemed like the place to start . . . . . . 'a known problem! Thanks again. Don