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idle surges when lights are on; idle surges when lights or fan is on
Topic Started: Oct 29 2012, 02:40 PM (712 Views)
johannes
New Member
[ *  * ]
My idle surges when the lights and or heater fan is on. It surges for like 20 sec and then
Refs at about 2500 rpm and then slowly goes down to normal idle but if I just touch the
Gas pedal it goes through the cycle again.
:banghead

Update.
I tried finding the diode but cannot find it. I even went to pick n pull and stripped another 1996 to try and find it to no avail.
Edited by johannes, Nov 15 2012, 02:31 PM.
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sheananigans


You are going to have to do quite a bit of testing to fix that as it could be a few different things. First thing to do would be to test your diode module, and the throttle position sensor. Has anyone ever messed with the factory throttle body settings? Eg: the throttle stop screw should be set to just barelly stop the throttle plate from sticking closed, and the tps should be set so that you get 0 volts at idle ranging up to 5 volts as you open the throttle plate.
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maddog
New Member
[ *  * ]
sheananigans, any tips on how to check the diode module,,, and its location.

(I am having the same, but opposite problem, my RPMs drop upon e-load)
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paul11211


It could be idle speed control?
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sheananigans


maddog
Oct 30 2012, 07:36 AM
sheananigans, any tips on how to check the diode module,,, and its location.

(I am having the same, but opposite problem, my RPMs drop upon e-load)
There is a post somewhere with a picture of the location of the diode module. Ill see if I can find it. Its located under the drivers side dash next to the ecu. You will have to remove the fuse panel to get to it. It is a small black box that sticks out of the wiring harness. As for testing it, you will have to use a DVOM and measure the current through each diode. Ill find the post on that as well


EDIT:: this post should help you out
http://geometroforum.com/topic/4916462/1/
Edited by sheananigans, Oct 30 2012, 12:56 PM.
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sheananigans


paul11211
Oct 30 2012, 07:59 AM
It could be idle speed control?
It probably isn't that, the fact that the idle is *surging* is an idicator that the isc is functioning. The idle is surging because the isc is constantly idling the engine up then dropping it back down, due to impropper information going to the ecu
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