[/QUOTE]Test#1 - Get a volt/ohm meter and set it to read 0 - 500 ohms. Unplug the cps and measure across the CPS leads, the CPS should measure aprox. 275 +/- ohms. If it's off by much, replace it.
Test#2 - You'll need a friend to help ya with this one.
Set your volt/ohm meter to read 0 - 5 AC volts or the closest AC Volts scale your meter has to this range. Measure across the CPS leads for voltage generated as your friend cranks the engine. (The engine can't fire up without the CPS connected but watch for moving parts just the same!) The meter should show .5 - .8 VAC when cranking. (That's between 1/2 and 1 volt AC.) If it's below .5vac, replace it.[/QUOTE]
I tried this on my '88XJ Limited last night. The engine runs fine otherwise but has this annoying momentary cut-out . . . it'll idle at just under 1000 rpm for a varied period of time and then, basically, just die, momentarily (severe drop in rpm) . . . most of the time, it then continues running. it never fails to start and ahs no "high-rev." When this condition was at its worst, I did the disconnect/wiggle-the-connection-around/re-connect at the CPS plug and it got noticeably better but did not entirely "cure" the problem. The CPS in there is a high altitude CPS and probably has less than 6000 miles on it. The engine ran fine for some, say, 5800 of those miles before this problem arose. There is no wire contact with the manifold, etc.
When I ran the test above, I got no resistence at all with test #1 and no voltage at all with test #2 ...................... yet, the engine runs?????
Don