4piknup
master of none
i can pick a bad isc by ear now, in all the '90 something mitsubishis (+hyundais). its like a valiant with a shagged ballast resister.
Idle Speed Control problems
- Thread starter 4piknup
- Start date
Help Support 4GTuner:
i can pick a bad isc by ear now, in all the '90 something mitsubishis (+hyundais). its like a valiant with a shagged ballast resister.
Lol i have a valiant and ive never shagged a ballast resistor?
If you werent interstate id drop it past yours!
4piknup
master of none
There is a YouTube link on page 1 of this topic. Of a good isc and a bad one (really I just unplugged it)
If yours starts the same wether plugged or not, it is bad. Typically they rev slightly high at initial start, then drop to the set revs at around 10 secs. The reason is that the start point is say 50% open, but the warm idle is at say 30%. so after it starts, the ecu rapidly shuts the isc and controls the idle
If yours starts the same wether plugged or not, it is bad. Typically they rev slightly high at initial start, then drop to the set revs at around 10 secs. The reason is that the start point is say 50% open, but the warm idle is at say 30%. so after it starts, the ecu rapidly shuts the isc and controls the idle
BZY247
Well-Known Member
Show us the pics!
Very overdue but here they are:
(GSR unit on the left)
(As you can see with plungers wound out to the maximum they are same length)
hi guys im new to this forum .. nice to meet u all .. i have a evo 3 rs . im having the same issue mention above .. i have to thank u all for uploading the driver IC replacement video .. after watching the video i removed the ecu cover and check the the ecu ..
saw the IC is cracked .. and i removed the ecu and i put another evo 3 ecu and i check that the driver ic is gone or not. its good from out side but when i start the car and put the ac the RPM goes down . and when i driving the RPM goes to 0 and off teh engine im soo confused like hell i dont knw wht to do please help me.. i checked the isc and it give me a range of 37 to 38 range for all the pins .. please help me out thank you ..
saw the IC is cracked .. and i removed the ecu and i put another evo 3 ecu and i check that the driver ic is gone or not. its good from out side but when i start the car and put the ac the RPM goes down . and when i driving the RPM goes to 0 and off teh engine im soo confused like hell i dont knw wht to do please help me.. i checked the isc and it give me a range of 37 to 38 range for all the pins .. please help me out thank you ..
4piknup
master of none
Unscrew the isc from the tb. Leave it plugged in and flick the key to run and then off again. See if the isc moves. You may need someone to watch for you
Maybe the ecu looks ok but is still blown anyway.
Maybe the ecu looks ok but is still blown anyway.
[sup]hi jack as u said i removed the isc and checked its moving when the key flicks .. i upload a pic of the ecu .. one driver is blown wht can i do now ..? i have another ecu with out any burn marks or any thing but when i fix that ecu and put the ac still the same issue idle goes down ..any idea ..[/sup]
wht can i do now ..? i have another ecu with out any burn marks or any thing but when i fix that ecu and put the ac still the same issue idle goes down ..any idea ..[/sup]Attachments
khubner1
Moderator
Have you checked the th isc is ok no blown coils.
4piknup
master of none
[sup]hi jack as u said i removed the isc and checked its moving when the key flicks .. i upload a pic of the ecu .. one driver is blown
So you checked resistance on isc coils and they are ok?
You undid isc and flicked key and isc moved?
Does it move with new ecu as well?
Only thing is idle screw is not set correct and maybe tps is not set correct.
You really need someone to set these as they are not accurate with multimeter.
But on vfaq there is specs for setting them.
I can fix your ecu but may as well get your engine right with your other ecu. I cannot test ecu after I have fixed it as my engine is not running. And your issues need fixing or you may blow the new ic again
ya i checked the resistance it came around 37 to 38 range to all the pins .. it that amount right ?.. i didnt remove the isc coil yet ill do it and give u a feed back .. jack where can i buy a driver ic .. i saw it on ebay are there good stuff to buy .. and im planning to give the car to check all the wiring and the isc , tps to fix it right for me . i dont knw how to do that .. jack do u think if i replace the driver ic + isc will the problem slove ..
jack do u think if i replace the driver ic + isc will the problem slove ..You undid isc and flicked key and isc moved? yes
Does it move with new ecu as well? yes
but still when i put the ac idle drops to 500 it should go up right and when i drive the car idle drops to 0 and its stop the engine when i take it off from the Gas paddle ..
Does it move with new ecu as well? yes
but still when i put the ac idle drops to 500 it should go up right and when i drive the car idle drops to 0 and its stop the engine
when i take it off from the Gas paddle ..
4piknup
master of none
ya i checked the resistance it came around 37 to 38 range to all the pins .. it that amount right ?.. i didnt remove the isc coil yet ill do it and give u a feed back .. jack where can i buy a driver ic .. i saw it on ebay are there good stuff to buy .. and im planking to give the car to check all the wiring and the isc , tps to fix it right for me . i dont knw how to do that ..
Resistance sounds about right.
You can pull driver ic from other ecu. But ecu needs to be checked for blown tracks as well.
I offer a service to repair these. So forgive me for not divulging all info. Its pretty easy to wreck your ecu.
Cant recall but isc should push out on key on and in on key off.
There are 2 driver ic. One pushes out other pulls in
ok got it so thatz means i have to replace 2 driver ICs thatz wht u mean right .. did u check the pic i send you .. i knw one is gone and how can i find the other driver ic .. u have any idea witch one .. if u look in to that pic.. and bro is it possible to check the driver ICs gone or not in the ecu .. ? thanks
4piknup
master of none
Have a look in the pics I posted from repairing them. It is next to your blown one. They are sidebyside
I cant remember and its in my book.
You can test them in the ecu. Measure all combinations of pins of the ic and compare to a good one
And trace the pins to their source or destination and check the component and the connection.
I need to update this thread and give more info. The ic are pretty cool. They basically a relay or in this case 2 Darlington pair (4 relays)
I cant remember and its in my book.
You can test them in the ecu. Measure all combinations of pins of the ic and compare to a good one
And trace the pins to their source or destination and check the component and the connection.
I need to update this thread and give more info. The ic are pretty cool. They basically a relay or in this case 2 Darlington pair (4 relays)
hi sorry for the late reply .. jack when i start the car and unplug the idle vale wire it wont give me a change is it normal??
and as u said me to put a ic base and fix the ic rigt where can i find a ic base bro search in ebay cant find it..
and as u said me to put a ic base and fix the ic rigt where can i find a ic base bro search in ebay cant find it
..
4piknup
master of none
If you start car and unplug wire it will not change.
This is correct.
remove isc from throttle body. Leave plugged in and turn key on and off. Isc should move in and out
This is correct.
remove isc from throttle body. Leave plugged in and turn key on and off. Isc should move in and out
4piknup
master of none
Wind your bas screw out 1 turn.
4piknup
master of none
Idk.
Seems like the isc works fine. Must be something else.
Tps, biss, siezed aircon pump, timing, blocked fiav or throttle body.
Seems like the isc works fine. Must be something else.
Tps, biss, siezed aircon pump, timing, blocked fiav or throttle body.
