If you ever need to replace your tranny (cheaper than a rebuild or popout fix) get a newer tranny out of a b14 or something, I think they don't have the 5th gear issues.
For your cruise, here's what my FSM says to do:
Turn A.S.C.D. main switch "off" and "on" to make sure indicator illuminates. If that checks out ok then check the power supply circuit for teh A.S.C.D. control unit. To do this, turn the main switch "on" and check the voltage between control unit harness terminals 3 and 4. (the control unit is just to the right of your fuse panel under the dash, it's this harness you'll "backprobe" as it needs to be connected to the control unit while checking) If voltage does not exist, check for continuity between control unit harness terminal 4 and A.S.C.D hold relay (located on the bottom left of the control unit). If voltage did exist, then check the cut-off circuit for the A.S.C.D. control unit. To do this, check voltage between control unit harness terminals 5 and 3. If no voltage was present, check the A.S.C.D. cancel switch, A.S.C.D. clutch switch (M/T models) and inhibitor switch (A/T models). If voltage was present, then check the set/coast switch circuit for A.S.C.D. control unit. To do so, with the ignition off, push and hold the set/coast button while checking for voltage between the control unit harness terminals 2 and 3. If there is no voltage, check to see if your horn works. If the horn works, check the Set/Coast switch itself, if the horn didn't work, check the fuse and horn relay. If voltage did exist, then check the speed sensor circuit. To do so, you need to jack up the front end of the car and set your parking brake. Check for voltage between control unit terminals 3 and 8 while turning the front wheel slowly. If the voltmeter didn't move any, check the speed sensor itself. If the meter did move, then check the A.S.C.D. pump. If the pump checks out ok, then check the pump circuit. To do so, with the control unit harness plugged in and the ignition turned on, check for voltage between terminals 3 and 8. It should be 0V. If there is voltage present, there is a short or open circuit in the pump harness. If there was no voltage, then turn the ignition off and disconnect the harness from the control unit. Measure resistance between control unit harness terminals 8 and 9, 8 and 10, and 8 and 14. Resistance should read as follows: between 8 and 9; about 8-45 ohm's, between 8 and 10; around 65 ohm's, and between 8 and 14; around 65 ohm's. If any of these resistances were not correct, the control unit needs to be replaced.
Now, what if you had to check out any of those components? Well here's how to check them:
A.S.C.D pump and actuator:
Disconnect the pump harness (the pump is located behind the driver's side shock tower in the engine bay) from the pump. Connect a piece of wire to your battery's positive terminal and the 1 spot on the pump's eletrical connector, and ground the 4. If the pump didn't start it needs to be replaced. If the pump did start, then check to see if the wire is pulled when 12 volts is applied to the 1 terminal on the pump connector, with terminals 2, 3, and 4 being grounded. If the wire wasn't pulled, disconnect the vacuum hose from the pump and check for vacuum pressure when the pump is run. If there was no vacuum pressure then the pump needs to be replaced. If there was vacuum pressure, then try replacing the vacuum hose that goes from the pump to the actuator. If it still doesn't work then your actuator needs to be replaced. If the wire was pulled during the previous set when you had voltage to terminal 1 and ground to 2, 3, and 4, then check to see if the wire returns to it's original position 50 to 60 seconds after you disconnect terminal 4 from ground. If the wire returned immediately, replace the pump. If it doesn't return until 50 to 60 seconds have passed, disconnect terminal 1 from the battery to see if the wire returns immediatly. If it doesn't return immediately, then replace the pump.
A.S.C.D. steering switch:
With the harness disconnected from the switches check continuity between terminals by pushing each button.
Set/Coast terminals 1 and 2
Resume/Accel terminals 1 and 3
Cancel terminals 1 and 2 and 1 and 3
I skipped the other stuff since you'd have other problems which you would have noticed other than just your cruise not working. Let me know if you need more help.
Here is a half assed rendition of your control unit harness, viewd from the harness side (the side you see the wires coming out of):
________|__|_________
|2 |1|X|9|3|10|13|12|X|X|
|11|7|X|X|5|4 |8 |14|X|X|
X's indicate unused terminal locations in the harness.
The pump electrical connector (on the pump itself, not the harness that connects to it) is like this:
___
|__|
/1|2\
\3|4/
Hopefully this will help, I spent 2 hours copying it for you.
As far as spark plugs go, the plugs of choice seem to be NGK. Then there are the Bosch haters out there, but I had Bosh Platinum +4's in my '93 XE for years and never had a problem, got great gas mileage as well. I'd say go with NGK's though.
