4g93t idling issues

[hayjimmy]

have just finished complete rebuild of my 4g93t and done some aftermarket upgrades, got the damn thing going and now when i come off the gas to go back to idle the engine dies out, have also tried holding the revs around 2000rpm however the revs fluctuate up and down.
Other forums I have found have suggested the problem could be the stepper motor.
Any suggestions?

 

[LWNSLW]

idle stepper motor is what its called, you could also have a bad air leak in your intake. From the air flow meter to were the intake manifold meets the head.... just listen for a leak if its that wont be hard to find....

 

[philsth]

As above and check all your intercooler plumbing, I had one come off and it did what your describing.

 

[3zercrowd]

Have you got an atmo BOV?
Unless your running insane boost, an Evo8 MR BOV (plumbed back in) will do the trick:thumbsup:

P.S. Start and Intro thread and also a members rides thread in respective sections

 

[lefty]

ISC - Idle Speed Controller

Although mine would stall the car.

 

[hayjimmy]

um yeah have checked for leaks, the pod filter goes straight onto afm and then str8 onto turbo via a silicon joiner as i hav upgraded turbo, all the intercooler piping has just been finished and checked time and time again. um yeah it stalls out when you come off the gas as well (forgot to add that). have got atmo bov (tial q) and hav changed the spring in it to match the vacuum levels. Is the idle speed contoller the same as idle stepper motor?

 

[hayjimmy]

just found out how to test isc with a multimeter, turns out only half of it had any resistance (plugs 1-2 and 5-6 i think) hopefully this is all i need

 

[Smutt]

If you dont get entire success with the ISC.... try below..

I have had the same issue come and go with my engine (same) and BOV, what do I do to fix it.... Spray some quality penetrant/ lubricant onto/ around the BOV's plunger seal as it comes up and vents to the atmosphere (sticky seal), the engine would also stall. You can do this via the engine bay, rev the motor and then back off and watch the BOV vent (this is when you spray the lube onto the plunger seal).

Should cost you.... nothing 5 mins tops.... Try it

But if your BOV is "brand new", it should not have any sticky issues, worth a shot tho..