ISC Video, is it good or bad?

[Devilsfutbol17]

I'm having idle issues and am curious as to the condition of my ISC motor. I see the video in this thread http://www.dsmtuners.com/forums/bolt-tech/378802-bad-isc-running-lean.html and it is leading me to believe my ISC motor is not functioning properly.

The resistances across the terminals are all 30 ohms, so I couldn't rule it bad from that. This is the video of my ISC

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This is the video of how it should apparently work

<object width="480" height="385"><param name="movie" value="http://www.youtube.com/v/l7R3gf7SiAo?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/l7R3gf7SiAo?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>

 

[1991GSXAWD]

Sometimes they can test ok but not work, try another ISC and if still don't work than I would start looking into the ISC driver being bad inside the ECU

 

[Devilsfutbol17]

The ISC I tested was the one that was first in my car. I bought one off a friend that had his motor apart hoping that his was good. It's one of the black ones and has a little higher resistances which I have read is normal for the plastic one. But it doesn't seem to be behaving any differently than my metal one. Logging it on my logger shows no real differences. I didn't know about testing it though when I put it in, so it has yet to be tested. I will check it and see how it moves. Thanks for the reply.

 

[rich3389]

Mine would do that when plug had a broken wire going into it. Make sure all your wiring especially into the plug is good.

 

[steve]

Time to check the ECU. The worst case damage you can see but I got ECUs all the time with damaged drivers that weren't burned up. The most typical being from when the 47uF cap leaked and bridged the ISC trace running under it to the 12v pin but I still saw plenty where the old ISC coils weren't a dead short but were reading lower than the 28 ohm spec for the original ISC and the driver couldn't pull it's end to ground anymore requiring replacement of the driver chip.

 

[Devilsfutbol17]

I'm going to try and put that same ISC in my friend's car and see if the motor test goes the same as it did in my car.

I will also take a look at the ecu. I pulled it out about two weeks ago to check out the capacitors and they all appeared just fine as well as the rest of the ecu, but I didn't examine or know where to look for the ISC drivers. If you could point me in the right direction to find the ISC drivers that would be great. I will start searching the forum now to see if I can figure it out. Thank you very much for your replies.

 

[Devilsfutbol17]

You nailed it on the head Steve. Thank you very much for your help. Does it look like my ecu should still have a chance if I repair it? The top side of the board looks good besides maybe the spot where I can't see directly under the 47 uF capacitor. I ordered the capacitors and I guess I'll have to go to the junkyard to get a donor ecu for the driver chip that got fried.

 

[Boomdeeze]

I have tried 3 ISC's and two of them moved for a second and then wouldn't move again. Is it possible I am shorting out every one of them? I have a 95 eprom and was tested and came out perfect. Any ideas?

 

[Devilsfutbol17]

If you have already visually inspected the capacitors and the ISC drivers, and you had the ecu tested, then I'm not sure what could be causing your problem besides like what rich3389 said about checking your wiring. Have you tried the ISCs in another car to verify it is your car or the ISC that is having the issues? If you tested it in your car, make sure the resistances across the terminals are still good before you test it in a friends car, don't want to mess up another ecu if that is the case.

 

[Boomdeeze]

I will have to pull my ECU then and check it again. I am doing a wire tuck this winter so I will be able to check all the wiring.