Welcome Guest [Log In] [Register]
Posted ImageWelcome to the all new Geo Metro Forum. We hope you enjoy your visit.

You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features:

Join our community!




Username:   Password:
Add Reply
Idle surge problem; Idle surges with lights on
Topic Started: Oct 10 2017, 10:31 PM (875 Views)
geogonfa
Member Avatar


Just my .02¢...Even though it's been a year I still recommend the compression test... :type

1.) Remove the diode pack from the circuit and see if the ISC reacts the same when you turn on any accessories...

2.) Check the Alternator voltage and amperage, alternator could be exerting too much drag and computer is trying to compensate for it when it's under a load (low compression wouldn't help :hmm )...

Offline Profile Quote Post Goto Top
 
freegeo
Member Avatar


geogonfa
Oct 14 2017, 07:50 AM
Just my .02¢...Even though it's been a year I still recommend the compression test... :type

1.) Remove the diode pack from the circuit and see if the ISC reacts the same when you turn on any accessories...

2.) Check the Alternator voltage and amperage, alternator could be exerting too much drag and computer is trying to compensate for it when it's under a load (low compression wouldn't help :hmm )...

:gp
Offline Profile Quote Post Goto Top
 
backyardmechanic93
Member Avatar
New Member
[ *  * ]
freegeo
Oct 14 2017, 09:08 AM
geogonfa
Oct 14 2017, 07:50 AM
Just my .02¢...Even though it's been a year I still recommend the compression test... :type

1.) Remove the diode pack from the circuit and see if the ISC reacts the same when you turn on any accessories...

2.) Check the Alternator voltage and amperage, alternator could be exerting too much drag and computer is trying to compensate for it when it's under a load (low compression wouldn't help :hmm )...

:gp
1. Will try removing it tonight and post results
2. How would I reduce the drag if that's the problem? Alternator and battery are about a year old (new water pump just installed due to growling bearing, idle still surging), tested charging system several weeks ago with vat 45, results were good. I was thinking the regulator might be the issue at first. Also, the revving/surging problem happened suddenly one day, it's not something that's slowly been getting worse.
Edited by backyardmechanic93, Oct 16 2017, 04:57 PM.
Offline Profile Quote Post Goto Top
 
backyardmechanic93
Member Avatar
New Member
[ *  * ]
Swapped out the TPS, problem solved. Thanks for the help/suggestions.
Offline Profile Quote Post Goto Top
 
freegeo
Member Avatar


Glad you got it fixed.

Usually a tps problem will effect idle also.
Offline Profile Quote Post Goto Top
 
backyardmechanic93
Member Avatar
New Member
[ *  * ]
freegeo
Oct 17 2017, 06:28 PM
Glad you got it fixed.

Usually a tps problem will effect idle also.
I started with the most likely causes, then kinda just swapped things until it fixed it :lol . It's odd because it seemed fine, I even tested the old tps with a multimeter too. Guess they only last 22 years. Now, all that's left is to get a tech 1 to set it properly. :D
Edited by backyardmechanic93, Oct 17 2017, 10:44 PM.
Offline Profile Quote Post Goto Top
 
freegeo
Member Avatar


You don't need a tech 1 to set it properly. Just a volt meter.

Wish i knew you might be interested in a Tech 1, I just sold mine on ebay.
Offline Profile Quote Post Goto Top
 
backyardmechanic93
Member Avatar
New Member
[ *  * ]
freegeo
Oct 17 2017, 11:07 PM
You don't need a tech 1 to set it properly. Just a volt meter.

Wish i knew you might be interested in a Tech 1, I just sold mine on ebay.
Well, that would save a few bucks because I have a voltmeter. Any chance you'd be able to describe which pins to use for the adjustment? Pro-demand is telling me voltage needs to be checked with a tech 1
Offline Profile Quote Post Goto Top
 
freegeo
Member Avatar


backyardmechanic93
Oct 18 2017, 11:59 AM
freegeo
Oct 17 2017, 11:07 PM
You don't need a tech 1 to set it properly. Just a volt meter.

Wish i knew you might be interested in a Tech 1, I just sold mine on ebay.
Well, that would save a few bucks because I have a voltmeter. Any chance you'd be able to describe which pins to use for the adjustment? Pro-demand is telling me voltage needs to be checked with a tech 1
The procedure is in the FSM. If someone else doesn't post it I will after I get off work.
Edited by freegeo, Oct 18 2017, 01:09 PM.
Offline Profile Quote Post Goto Top
 
suzukitom
Member Avatar
Tom

voltage measured using Terminal 1 (sensor ground) and Terminal 3 (Throttle Position input). Insert TPins into TPS connector so you can backprobe with your voltmeter on low voltage DC scale. (0-10V)

Measure with 0.14 inch feeler gauge inserted between throttle stop and throttle valve screw. (9/64" drill bit equivalent diameter). ISC motor plunger tip must not be pressing against its stop.

Voltage for properly adjusted TPS should be between 0.98 to 1.02 V with 0.14 inch feeler gauge inserted. Picture just shows my initial reading.


Posted Image

Edit: my wire colors are different in this picture since I made a permanent extension harness from my TPS so I that I don't have to use TPins to check voltage.
Edited by suzukitom, Oct 18 2017, 02:02 PM.
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
« Previous Topic · Engine Tech & Diagnostics · Next Topic »
Add Reply