Idle slowly getting worse

[kaganader]

Okay back in the summer my idle was perfect, started up cold around 1400 then falling to 800 when warm. Now cold start up is around 1000-1150 and when warmed up is will go to 1400-2100rpms (it is set at 950rpm in dsmlink). I have the biss screw almost all the way in to keep the idle as low as it can be.

After replacing the ISC motor with a new one, it kept the same idle characteristics but starts at 1000 on cold startup and stays at 1000 even warmed up, but now when driven it will rise up to the 1400-2000rpms when driven and stopped at a red light when put into neutral. If I sit there for a minute or so in neutral the idle will come back down to 1000 and stay there till I start driving and come to the next red light where it will be hovering back up there again.

• I've replaced the ISC motor with a new black one
• New biss screw and o-ring
• Fixed all the vacuum leaks I have found
• Fixed small boost leaks I had
• No EGR or emissions hooked up and vac nipples put on all of them and TB.
• gave the throttle cable 3/8" slack so when it warms up it does not open or pull the throttle blade at all.
• I do not have the FIAV block off since I use this car in NY and would not want to deal with holding the gas pedal a little to warm it up everyday.

My TPS in dsmlink is at 0% on idle (was at 1% and corrected it)
I don't throw any CEL codes and my thermostat is working in spec last time I checked.

What do you guys think I should do/check next?

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

 

[kaganader]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

Read that, followed it, did not help. Left me thinking FIAV but I do not want to block it off since the car is used in cold weather start ups and would be a pain to hold the gas a little on every startup.


I also see you do post this on every Idle thread without actually giving any opinion/help of your own, since I do lurk around a bit looking for answers before asking for help.

 

[DeathdealerATX]

maybe a dirty TB, have you cleaned the tb lately?

 

[kaganader]

maybe a dirty TB, have you cleaned the tb lately?

Cleaned the tb about a month ago. I can always give it another cleaning if it has gotten dirty.

 

[mtwollet]

have you tested the isc motor, http://www.dsmtuners.com/forums/articles-tuning-ecu/386663-dsm-isc-motor-testing-replacement.html

mine i bought on ebay 2x, probably because they were both used.

 

[kaganader]

have you tested the isc motor, http://www.dsmtuners.com/forums/articles-tuning-ecu/386663-dsm-isc-motor-testing-replacement.html

mine i bought on ebay 2x, probably because they were both used.

Yup tested the ISC, all within specs. It is the new black one that mitsu uses, don't have the box near me to get the manufacturer number.

Have the ISC motor from here.
main page

On another note, my Alternator just died on me tonight on the way home, barely made it home and died as I was getting on my block ( I had the battery and brake alternator death light for some time now). I will replace that tomorrow and do some more diagnosis on what could be the culprit for the idle.