2G Idle Speed Controller (ISC Motor) Issue

[Sp00lin16g]

My 97 talon is idling like crap. I have replaced many gaskets and it still idles poorly. I swapped the stock T25 turbo because it had blown seals and replaced it with a 16G ... the car idled fine before and now I'm dealing with this ..

Any thoughts on stock talons with blown turbos and swap to a larger turbo -- Need help finding boost leaks?
-When I unplug the ISC motor / Idle air control valve the rpm's don't change and the car doesn't die ???

Help .. thanks guys

 

[YUPOK]

Several issues here.

I hate to disappoint you but a 16g with a stock setup is too much. You need supporting mods to run correctly.

i highly recommend reading the general tech and intro forums. It will explain where to start looking for your idle issue and to get your car setup to run smooth and true.

 

[Sp00lin16g]

Thanks for the advise .. I'll add more detail to paint a better picture of my journey so far and the solutions I'm attempting.

 

[97 eclenger]

idle doesn't change because your idle is run off the biss. once the idle is set on that is when you plug the iac in. the iac sits in a neutral position. which is also the idle position. that just means your idle is set correctly or near correct. look for boost leaks. and type of boost/ vacuum leak will result in a bad idle. if you changed plugs or plug wires and have wires wrong thats another thing. another thing to look at is the coolant temp sensor. if thats bad it will also cause problems.. cleam the maf to. check all that

 

[steve]

Unlike some other cars the ISC doesn't automaticly close when you unplug it. It just stays where it was last.

 

[Sp00lin16g]

Hey thanks alot for the input guys .. I have done alot of maintenance on it, which is why I not sure what else to do?

 

[Sp00lin16g]

idle doesn't change because your idle is run off the biss. once the idle is set on that is when you plug the iac in. the iac sits in a neutral position. which is also the idle position. that just means your idle is set correctly or near correct. look for boost leaks. and type of boost/ vacuum leak will result in a bad idle. if you changed plugs or plug wires and have wires wrong thats another thing. another thing to look at is the coolant temp sensor. if thats bad it will also cause problems.. cleam the maf to. check all that

Thank you .. I will try that and let you know how it goes

 

[Sp00lin16g]

Maintenance:
-installed 16G turbo -- replaced stock blown T25 turbo
----used the conversion kit from extremepsi
----not sure if the oil restrictor that it came with is correct?
-----the oil drain leaks ??? I used the oem 2g tube and lobed out the holes -- can't get it to seal properly??
-valve cover gasket + spark plug gaskets
-timing belt + OEM tensioner + gate waterpump
-OEM NGK spark plugs + (blue wires) bosch #09246
-removed the charcoal canister
-removed egr valve
-removed the 2 or 3 solenoids on the firewall
-injector insulators
-installed used injen intake pipe
-replaced o2 sensor - on o2 housing
-coolant flush + oil change
-throttle body gaskets (2) -- Not the shaft seals
-biss o-ring
-oil cap gasket
-exhaust manifold gasket + studs + nuts
----noticed the exhaust manifold studs/nuts were easy to remove -- not sure why?
----noticed the turbo to manifold bolts were loose -- had an exhaust leak -- I may have not torqued them enough?
----noticed tons oil near the head/exhaust ports/coolant tube - I'm guessing from the bad head gasket?
-the car is burning oil ---- I was told it's my valve seals?
-I'm 95% sure this is all the maintenance I have done so far

Future:
-Ordered HKS hi-power cat back exhaust
-ordered megan racing downpipe
-ordered ecmlink -- full kit

Thanks for all the help guys -- this site is SOOO helpful/love the dsm guys

 

[Sp00lin16g]

Here are some pictures

 

[YUPOK]

See below in RED



Maintenance:
-installed 16G turbo -- replaced stock blown T25 turbo Good Job getting MHI on there.
----used the conversion kit from extremepsi
----not sure if the oil restrictor that it came with is correct? Shouldn't need an oil restrictor for 16G
-----the oil drain leaks ??? I used the oem 2g tube and lobed out the holes -- can't get it to seal properly?? Try grabbing a steel braided drain hose kit. They are not terribly expensive and much more durable than the stock hard pipe.
-valve cover gasket + spark plug gaskets
-timing belt + OEM tensioner + gate waterpump
-OEM NGK spark plugs + (blue wires) bosch #09246
-removed the charcoal canister
-removed egr valve
-removed the 2 or 3 solenoids on the firewall You can plug these solenoids back in to prevent a CEL
-injector insulators
-installed used injen intake pipe
-replaced o2 sensor - on o2 housing
-coolant flush + oil change
-throttle body gaskets (2) -- Not the shaft seals
-biss o-ring
-oil cap gasket
-exhaust manifold gasket + studs + nuts
----noticed the exhaust manifold studs/nuts were easy to remove -- not sure why?
----noticed the turbo to manifold bolts were loose -- had an exhaust leak -- I may have not torqued them enough?
----noticed tons oil near the head/exhaust ports/coolant tube - I'm guessing from the bad head gasket?
-the car is burning oil ---- I was told it's my valve seals? Hopefully this was from the blown T25 and would explain the oil burning issue as well. Are you still having this problem with the 16G?
-I'm 95% sure this is all the maintenance I have done so far

Future:
-Ordered HKS hi-power cat back exhaust
-ordered megan racing downpipe
-ordered ecmlink -- full kit

Also need to upgrade your fuel system to support the bigger turbo.
Start with the basics, compression test and boost leak test.

 

[Sp00lin16g]

Comments in green

Maintenance:
-installed 16G turbo -- replaced stock blown T25 turbo Good Job getting MHI on there. -- whats MHI mean?
----used the conversion kit from extremepsi
----not sure if the oil restrictor that it came with is correct? Shouldn't need an oil restrictor for 16G
-----the oil drain leaks ??? I used the oem 2g tube and lobed out the holes -- can't get it to seal properly?? Try grabbing a steel braided drain hose kit. They are not terribly expensive and much more durable than the stock hard pipe. -- will check that out
-valve cover gasket + spark plug gaskets
-timing belt + OEM tensioner + gate waterpump
-OEM NGK spark plugs + (blue wires) bosch #09246
-removed the charcoal canister
-removed egr valve
-removed the 2 or 3 solenoids on the firewall You can plug these solenoids back in to prevent a CEL -- will plug them back in
-injector insulators
-installed used injen intake pipe
-replaced o2 sensor - on o2 housing
-coolant flush + oil change
-throttle body gaskets (2) -- Not the shaft seals
-biss o-ring
-oil cap gasket
-exhaust manifold gasket + studs + nuts
----noticed the exhaust manifold studs/nuts were easy to remove -- not sure why?
----noticed the turbo to manifold bolts were loose -- had an exhaust leak -- I may have not torqued them enough?
----noticed tons oil near the head/exhaust ports/coolant tube - I'm guessing from the bad head gasket?
-the car is burning oil ---- I was told it's my valve seals? Hopefully this was from the blown T25 and would explain the oil burning issue as well. Are you still having this problem with the 16G? Yes there is smoke that comes out of the exhaust when I just start the car/cold start -- it doesn't smoke like the blown T25 did, FYI
-Ran seafoam through engine many many times -- in intake/gas tank/small amount in combustion chamber

Future:
-Ordered HKS hi-power cat back exhaust
-ordered megan racing downpipe
-ordered ecmlink -- full kit --- will adjust the tps properly when ecmlink is installed

Side notes:
-Running off of wastegate at 12psi
-turbo oil feed like runs from the oil filter housing

Issues:
-has an aftermarket/custom gauge cluster face and when I plug the OBD2 reader into it (to read codes .. etc) I can view the rpm's from the device. At idle on the gauges says 1,100ish and the reader says 900ish???
-According to the gauge I do not build/peak boost until 4500rpm's --- that's sooo high right??
-When I unplug the idle speed controller (ISC Motor) nothing changes - no rpm change or anything??
-when boosting it will hold at 12psi but sometimes creep to 20psi if i keep accelerating ?? -- I prob need a boost controller??
-when boost leak testing I pump it up to 20psi and in creeps down right away to 0psi in under 30 seconds???

Also need to upgrade your fuel system to support the bigger turbo.
Start with the basics, compression test and boost leak test. -- do you know how I could get smoke in the system when I boost leak test it ?? been boost leak testing with soapy water -- can't find the other leaks??

 

[Sp00lin16g]

Unlike some other cars the ISC doesn't automaticly close when you unplug it. It just stays where it was last.

How likely do you think it is that my ISC motor has gone bad??
-car has just under 150,000 miles

 

[97 eclenger]

comments in clear

to put smoke in the system could be like a fog machine is easiest. start at the throttle body and work your way to the turbo. thatd help isolate the leak

 

[Sp00lin16g]

comments in clear

to put smoke in the system could be like a fog machine is easiest. start at the throttle body and work your way to the turbo. thatd help isolate the leak

Hey thanks .. I'll try that and let you know how it goes

 

[97 eclenger]

odds are if its in the intake, its throttle shaft seals or a vacuum line, before that would be bov. and then intercooler

 

[Sp00lin16g]

odds are if its in the intake, its throttle shaft seals or a vacuum line, before that would be bov. and then intercooler

Right, ok thanks again I'll keep boost leak testing haha

 

[Sp00lin16g]

Anyone have any other advise??

 

[Sp00lin16g]

Unlike some other cars the ISC doesn't automaticly close when you unplug it. It just stays where it was last.

I just purchased ecmlink .. hopefully this will help me dial the idle in as well as air and fuel trims

 

[Sp00lin16g]

What's ya'll opinion on the coolant temperature sensors going bad and causing the car to idle higher/poorly??

 

[YUPOK]

If you put the money out for ECM link spend the couple bucks and replace the IAC and temp sensor and TB seals.

MHI= Mitsubishi heavy industries meaning you have a good turbo on there not knock off.

 

[Sp00lin16g]

If you put the money out for ECM link spend the couple bucks and replace the IAC and temp sensor and TB seals.

MHI= Mitsubishi heavy industries meaning you have a good turbo on there not knock off.

Ok good call .. thanks for all the help

 

[Sp00lin16g]

If you put the money out for ECM link spend the couple bucks and replace the IAC and temp sensor and TB seals.

MHI= Mitsubishi heavy industries meaning you have a good turbo on there not knock off.

Are these sensors something you would purchase from rockauto or find the oem ones somewhere?

 

[YUPOK]

I bought both from rock auto and they are working just fine.

 

[Sp00lin16g]

I bought both from rock auto and they are working just fine.

Nice .. I'll keep ya up to date on how it goes

the plan:
-ecmlink v3
-IAC valve / ISC motor
-both coolant temperature sensors
-megan racing downpipe
-HKS hi-power cat back

 

[redfield102j]

Not sure if you got the boost leak test figured out. When i do a boost leak test i charge the system and spray all joints and conections or any possible leak area down with soapy water and watch for bubbles. Easiest way i know to find a air leak. Hope this helps