Wimpy GTS
04-05-2002, 10:08 AM
#16
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The idle/WOT switch is a two-part switch unit mounted on the throttle body.
At idle, the idle switch is closed, from just off idle it is open. This tells the ECU that the throttle is closed, so that the ECU can change the mixture for best idle, retard the ignition timing by about 10 deg, and cut the fuel flow off at above 1200 rpm.
The key here for you may be the ignition retard. If the idle switch is bad, the idle may be too high.
To test the switch:
Pull the plug from the EZK ECU. Hold the plug horizontal, facing the bare contacts, so that the cable comes in on your right end (up thru '89, reverse for '90 & up). Terminal 1 is on the right bottom, 18 on the left bottom, 19 on right top, 35
on left top.
Idle Switch:
Hook an ohmmeter between terminals 8 and 18. With the throttle closed, there should be very low (less than 10 Ohms)resistance between these two terminals. When the throttle pedal is VERY slightly depressed, the resistance should change to infinite.
At idle, the idle switch is closed, from just off idle it is open. This tells the ECU that the throttle is closed, so that the ECU can change the mixture for best idle, retard the ignition timing by about 10 deg, and cut the fuel flow off at above 1200 rpm.
The key here for you may be the ignition retard. If the idle switch is bad, the idle may be too high.
To test the switch:
Pull the plug from the EZK ECU. Hold the plug horizontal, facing the bare contacts, so that the cable comes in on your right end (up thru '89, reverse for '90 & up). Terminal 1 is on the right bottom, 18 on the left bottom, 19 on right top, 35
on left top.
Idle Switch:
Hook an ohmmeter between terminals 8 and 18. With the throttle closed, there should be very low (less than 10 Ohms)resistance between these two terminals. When the throttle pedal is VERY slightly depressed, the resistance should change to infinite.
04-05-2002, 10:52 AM
#17
Electron Wrangler
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Thread Starter
Andre & Wally,
Thanks for this new idea.. certainly worth a try as its a lot less invasive and seems rather consistent with the symptoms.
Wally - thanks for the great detail (as always!)
I'll be trying it this weekend - I'll let you know...
Alan
Thanks for this new idea.. certainly worth a try as its a lot less invasive and seems rather consistent with the symptoms.
Wally - thanks for the great detail (as always!)
I'll be trying it this weekend - I'll let you know...
Alan
