Overheating and surging idle 99 z24

[ollie31]

I have a 99 z24 and am having a few problems. I am having an idle surge problem where my idle surges to 1500 and back to normal. Sometimes when I start the car it goes straight to 3000. I have also been having an overheat problem and discovered that the fan isnt working. It seems like at times that the idle surge happens when the engine starts to get hot. Any ideas??? I already disconnected the neg battery cable and no fix. Thanks for the help

[ollie31]

The fan also does not work when the A/C is turned on

[rhandwor]

When the car is up to operating temperature tap the fan motor with a hammer if it starts replace the fan motor.
Or you can use a test light and probe both connections just pull the plug apart slightly. If one side lights the light hook the ground on the positive cable and touch the ground side and the light should work.
http://www.autopart.com/tools/toolsmain/tool/T_3023.htm Also look at 3031
use search. You should have two fans one is turned on by a temperature sensor the two wire unit. The other one is turned on by the A-C system.
You should have a relay for both units.
http://www.alldata.com/ sells a years subscription for $29.95 they have good wiring diagrams.

[ollie31]

Originally Posted by rhandwor

When the car is up to operating temperature tap the fan motor with a hammer if it starts replace the fan motor.
Or you can use a test light and probe both connections just pull the plug apart slightly. If one side lights the light hook the ground on the positive cable and touch the ground side and the light should work.
http://www.autopart.com/tools/toolsmain/tool/T_3023.htm Also look at 3031
use search. You should have two fans one is turned on by a temperature sensor the two wire unit. The other one is turned on by the A-C system.
You should have a relay for both units.
http://www.alldata.com/ sells a years subscription for $29.95 they have good wiring diagrams.

it turned out to be the fan motor. Any clues on the engine surge? As soon as I start the car the idle goes to 3000 and sits there. When driving the idle goes from 700 to 1500. Thanks

[rhandwor]

I would check the TP sensor circuit.
http://gearchatter.com/viewpost14227...o7f75676b21162