Reply To: Inconsistent rpm at idle, stalling + jerky acceleration GT250 EFI 2010
Can you confirm that if the ISCV actually sits inside the airbox or it has its own clamshel ?
I believe you have a clamshell that hangs on the frame to feed air on the 3 pipes sticking out of it.
I have an idea = Put the ISCV back in place and fit it inside the metal shell or airbox = Does it still “hit” the end of the airbox/clamshell?
If you pull it out again, it should have been keept in place instead of springing forth too far out.
Next tip = It will sound foolish but bare with me….
1. If you have a metal shell , put the ISCV inside it and screw it in so the O-Ring doesn’t leak air.
2. BIG pipe going to airbox ==> clean that area (hygiene!)
3. 2 pipes sticking out at the bottom ==> your other hand expose its palm to them.
4. blow air with your own mouth (unless you have a very LOW volume air compressor machine , attach pipe to it)
Can you feel air coming out on both bottom 2 metal holes ?(these holes feed the intake pipes anyway)
Turn the KEY ON
Keep blowing
Do you feel the air getting more restricted ?
If you turn the key OFF
Is the air completely blocked (you can’t blow no more)
Turn key on , it should retract backwards ? to the OFF state in the picture while key is on (I can’t confirm yet if the ECU can sense if its gone too far out and must retract it back a little bit but it may engage once the MAF sensor tells the ECU how much air is flowing in the throttle bodies while in stand still to maintain 1800 rpm revs, it’s a little trickier to study Sentec/Daewoo ECU’s than it is DELPHI units)
This is a weird test I am suggesting but you want to confirm , the same behaviour is happening to the NEW and OLD ISCV units ? Always make sure battery is charged though because that fuel pump draws a LOT of power and we don’t want to stress the pump too much also. It’s more expensive than the ISCV unit.