ISC Ohm Check=Bad; Relpace with Tan vs. Black

[jnf63]

I checked my ISC on my 1995 GSX because of idle surge. Using "Welcome to my Idle Speed Control (ISC) Test/fix page," I noted that pin combination 4-5 reads nothing (infinity) on an Ohm meter. All other pin combinations tested as 30 Ohms (1-2, 2-3, 5-6). Now, my ISC is Tan. I am assuming this means that my ISC is bad, leading to a possible reason for the idle surge. Is it most proper to find a used, operating Tan ISC to replace the bad one? Will a used, operating Black ISC be a correct replacement without later difficulties? Is it easier to repair the bad Tan ISC (coils?)? I have read several "opinions," yet I would appreciate an experienced (successfully achieved) explanation. I am basing my questions on my interpretation of the thread "ISC Test Results" which states, "Is the ISC with the black cover supposed to read higher (Ohms) like that? And if so will that mess things up with my ECU reading more Ohms than it was supposed to from factory?" ... "Going by the numbers the tan one 'should' work better but you can give the black one a try and see how it goes. Remember to adjust the idle/biss again."

Thank you for any assistance.

 

[carbide]

I've always been told the BLACK Isc's are better, they have a better design and are the newer style. My recommendation: Just get a new one! www.dsmisc.com is the cheapest place I've seen.

And a used tan one will most likely be broken, too.

And a bad ISC will cause idle surge.

 

[91AWDGSX1G]

Black is better. It has a higher resistance compared to the tan. The tan has 28-33 ohms and the black is 40 ohms.

Read number 9 on this page:

DSMISC FAQS page

 

[jnf63]

Thank you for your replies. Each of your explanations have convinced me that using the newer Black ISC is the proper choice.

I hope replacing the bad Tan ISC (see photo) cures my idle surge. Otherwise, I shall have to use the process of elimination to find all the culprits.

 

[doggo]

I checked my ISC on my 1995 GSX because of idle surge. Using "Welcome to my Idle Speed Control (ISC) Test/fix page," I noted that pin combination 4-5 reads nothing (infinity) on an Ohm meter. All other pin combinations tested as 30 Ohms (1-2, 2-3, 5-6). Now, my ISC is Tan. I am assuming this means that my ISC is bad, leading to a possible reason for the idle surge. Is it most proper to find a used, operating Tan ISC to replace the bad one? Will a used, operating Black ISC be a correct replacement without later difficulties? Is it easier to repair the bad Tan ISC (coils?)? I have read several "opinions," yet I would appreciate an experienced (successfully achieved) explanation. I am basing my questions on my interpretation of the thread "ISC Test Results" which states, "Is the ISC with the black cover supposed to read higher (Ohms) like that? And if so will that mess things up with my ECU reading more Ohms than it was supposed to from factory?" ... "Going by the numbers the tan one 'should' work better but you can give the black one a try and see how it goes. Remember to adjust the idle/biss again."

Thank you for any assistance.

Some comments regarding the above-

1) The tan ones are old and obsoleted by Mitsu. If you can find a 'used' one, it's probably almost dead or has some coils replaced with other old tan ISCs in order to make a (for a short time) working unit. The old tans start to die around 75,000 miles. IF you can somehow find a NEW one in Box unused, it'll work fine, but even then it is using more power than the new black ones use, because it runs on a lower resistance level than the new black ones. And the tan units just arent as consistent in their ohm reading for each coil- meaning one coil will probably always be a little bit hotter than the others, meaning its gonna fail sooner rather than later. There is a reason Mitsu obsoleted these tan ISCs and replaced with the black ones- the reason being the black units have better electrical specs.

2) The black ones 'work' better than the tan ones. Period. Main reason is because they draw less power from your ECU- and that HAS to be a good thing considering we are all running ECUs that have anywhere from 10 to almost 20 years on them. Our stuff is getting old, guys!.

Get this, in 2011 I'm getting historical plates for my Talon. Amazing, huh?

 

[fwdmaster]

Get the black revised version

 

[jnf63]

Thanks for the helpful replies. I went with a Black ISC. My BISS O-ring was another culprit. Now, I have no boost leaks or defective idle components. Once I get my A/T situation fixed (ruined by the last shop working on my car [waiting for the money won in court to fix it]), I can confirm the idle.
Jim