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Ethan5150
Samba Member
Joined: September 01, 2010
Posts: 294
Location: Los Gatos, CA
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 Posted: Tue Sep 27, 2011 3:34 pm Post subject: Idle Stabilizer Question |
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Ok, well I'm a bit confused. My engine seems to have minor drops in power when being given just a tiny bit of throttle (imagine driving 5 mph and having it just drop a bit every couple seconds). Also, once the engine is warmed up, it tends to surge right when it drops to idle for a minute before settling back down to a smooth idle. My first steps were going to be:
* Check idle stabilizer
* Check timing
* Check all vacuum lines
* Check charcoal cannister
* Replace fuel filter & maybe pump
So I started by locating the idle stabilizer, and hey - it's not hooked up at all! This is how I got the van, with the IS just bolted to the side wall with no wires plugged in. So I found one wire with three male pins coming from the engine (not sure exactly where) but I assume that's one of the plugs for the IS. But where is the 2nd plug supposed to come from? The Bentley looks like it's showing another set of wires coming from the ICU but I'm not seeing any unplugged wires coming from the ICU... can someone tell me what I'm missing? Also, are the steps above what you all would recommend I take?
Last edited by Ethan5150 on Tue Sep 27, 2011 4:19 pm; edited 1 time in total |
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vogler
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Joined: April 01, 2011
Posts: 31
Location: Bloomington, Indiana
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| Posted: Tue Sep 27, 2011 4:17 pm Post subject: |
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[/img]
Both of the male and female plugs come from the same part of brownish colored sheathing. The wiring diagrams show how circuits are connected in the most easiest form so as to make sense on paper(and our brains) Now in real life there may be several feet of wire from one component to another. It takes some time to trace down a circuit if it is ran all around, under, over, zip tied, etc. You should be able to find the missing connector or a severed group of wires if it was cut. |
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vogler
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Joined: April 01, 2011
Posts: 31
Location: Bloomington, Indiana
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| Posted: Tue Sep 27, 2011 4:59 pm Post subject: |
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| I just went down in the garage and took another look at my van. The harness goes from the coil, idle stabilizer, ignition control unit(black little box to the right of idle stabilizer), to the distributor, and to the ecu eventually. I would have to look at my Bentley book to verify. I would start undoing the zip ties that hold all the harnesses together and sort through to find where the lost connection is. |
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Ethan5150
Samba Member
Joined: September 01, 2010
Posts: 294
Location: Los Gatos, CA
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| Posted: Wed Sep 28, 2011 12:47 pm Post subject: |
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| Ok, so this helped - thanks everyone. I found the two connectors that are supposed to be connected to the idle stabilizer connected to each other. I'm going to plug them into the stabilizer now and see what happens. Oddly, the wire I'm holding in the picture is ANOTHER wire that appears to have the same end but goes down to the engine...so I have no idea what that's for...but I'll try working with the two that were plugged together for now and see what happens... |
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windnsea
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Joined: May 07, 2008
Posts: 424
Location: Pasadena, CA
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| Posted: Wed Sep 28, 2011 12:53 pm Post subject: |
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The two that were plugged together - that bypasses the idle stabilizer control for setting the timing according to the Bentley manual. After setting the timing you're supposed to reconnect the control to the two plugs.
If you ever have the engine suddenly cut out and then will restart after it cools down, it might be the control unit. Bypass it, as yours was, and it will restart immediately if the control unit is bad.
Cheers!
I Have never seen another plug like these two going to the engine or anywhere else! |
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ajdenette
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Joined: February 15, 2009
Posts: 768
Location: Hope Valley RI
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Ahwahnee
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Joined: June 05, 2010
Posts: 9800
Location: Mt Lemmon, AZ
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| Posted: Wed Sep 28, 2011 2:03 pm Post subject: Re: Idle Stabilizer Question |
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| Ethan5150 wrote: |
| ...Also, are the steps above what you all would recommend I take? |
I would add a check and adjustment of the throttle position switches. |
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Ethan5150
Samba Member
Joined: September 01, 2010
Posts: 294
Location: Los Gatos, CA
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| Posted: Wed Sep 28, 2011 11:41 pm Post subject: |
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| Awesome - thanks everyone! So with the idle stabilizer, short of it killing the engine if it's bad, is there any other way to tell if it's doing what it's supposed to be doing? In other words, if it doesn't kill the engine, can I then just assume that it's good or is it still possible it's not "stabilizing my idle" as it's supposed to? |
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Ethan5150
Samba Member
Joined: September 01, 2010
Posts: 294
Location: Los Gatos, CA
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| Posted: Mon Oct 03, 2011 12:41 pm Post subject: |
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| Well, one problem fixed, one to go. After plugging in the idle stabilizer, my engine no longer hunts during idle. This is the good news. The bad news is the engine still lurches slightly at very low RPM (most notably in 1st gear). I replaced the fuel filter and that didn't seem to help. I'm going to dump the 2nd half of a bottle of Sea Foam in once I go through this tank of gas but is there anything else that can be causing this? I haven't checked the timing yet but I would assume poor timing would cause issues beyond just the lurching at very low RPM. Also, I just timed it a month ago and it runs great in every other situation. Should I replace all the vacuum lines now? Fuel lines? Injectors? |
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dobryan
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Joined: March 24, 2006
Posts: 16503
Location: Brookeville, MD
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elsyr
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Joined: May 06, 2008
Posts: 270
Location: North Florida
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| Posted: Tue Oct 04, 2011 5:06 am Post subject: |
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Might add checking the o2 sensor to the list. As ajdenette mentioned - the mystery wire in your hand in the picture is the top-dead-center sensor connector.
Doug
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'89 Carat "Brunhilde" |
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raultperez
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Joined: March 07, 2002
Posts: 3
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| Posted: Sun Jun 17, 2018 9:07 am Post subject: |
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Check ur spark plug order. Make sure they are right. I had a similar problem and turned out the the firing order was flip in one side.
| Ethan5150 wrote: |
| Well, one problem fixed, one to go. After plugging in the idle stabilizer, my engine no longer hunts during idle. This is the good news. The bad news is the engine still lurches slightly at very low RPM (most notably in 1st gear). I replaced the fuel filter and that didn't seem to help. I'm going to dump the 2nd half of a bottle of Sea Foam in once I go through this tank of gas but is there anything else that can be causing this? I haven't checked the timing yet but I would assume poor timing would cause issues beyond just the lurching at very low RPM. Also, I just timed it a month ago and it runs great in every other situation. Should I replace all the vacuum lines now? Fuel lines? Injectors? |
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raul |
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