Rough Idle

[RoccoMarcellus]

Installed the VRSF High Flow intakes a few months back and flashed the OTS Stage 2 map from BM3

The car has been running well. Recently got a rough cold start. So I have not used the car. No-fault codes etc

Is this because of my open pod intakes? What's the reason for this?

I don't think it's my ignition coils or spark plugs because I did not get a fault code ( however I did not use the car )

[MJ6]

Aftermarket intakes are well known to cause idle issues on this platform.

If it's just an issue at cold start and you're not throwing any codes, you can either:
- A: accept it for what it is, or
- B: as you're already using BM3, increase your cold start RPM and see if it helps with the rough idle

[hellokitty]

Double check your clamp connections. I had a similar issue with my intake, but one of the clamps loosened over time causing an air leak.

[hellokitty]

Originally Posted by MJ6

Aftermarket intakes are well known to cause idle issues on this platform.

If it's just an issue at cold start and you're not throwing any codes, you can either:
- A: accept it for what it is, or
- B: as you're already using BM3, increase your cold start RPM and see if it helps with the rough idle

Having the same issue. What do you recommend for cold start rpm?

[BrettG06878]

Following

[hellokitty]

Originally Posted by JackReacher2610

did yours still have a rough idle even after a cold start ? what intakes were you using ?

Forge intake. I went back to OEM intakes for the time being. I'm still trying to troubleshoot the issue but the rough idle is still there but much better now.

I'm running full e85 btw so that may be the issue

[rmanm4]

Originally Posted by hellokitty

Forge intake. I went back to OEM intakes for the time being. I'm still trying to troubleshoot the issue but the rough idle is still there but much better now.

I'm running full e85 btw so that may be the issue

Did you reset adaptations after installing the intake?

I have the same forge intake, had rough idle after 2-3 days of installing it, reset adaptions and now no rough idle. I also had hidden error code regarding MAF sensor reading too much air, that also went away after reset.

Drive around first and warm the car up real good, then do a adaptation reset via ISTA+, then go beat the car real good. Drive it hard, WOT as much as you can.

[rmanm4]

Originally Posted by JackReacher2610

Whoops, I did not reset adaptations. I flashed to stage 2 after installing the downpipes and intakes at the same time. I will reset adaptations after this and see how it is.

Should I reset adaptations first then do a cold start? or must I warm up first ( worried that if its my coils then i might have an issue pop up while driving around and since its lockdown then it will cause another problem for me since I might not be able to get assistance to tow the car etc )

I've always reset adaptations after car is fully warmed up. This way you are ready to push car to its limits. You don't want car learning granny style driving/limits. Now, mind you, car will adjust adaptations over time but you don't want the base to be lazy driving. Its like when you reset MPG on a car (the base will be different if you crusing on highway vs city stop and go).

[RoccoMarcellus]

Update: so when i was on stage 2, i didnt have any codes and i tried to force a code but nothing appeared. Flashed back to stock map and i got a cylinder 6 misfire.

Turns out that I had a leaking injector which damaged coils for cylinder 5 and cylinder 6. I have replaced the coils and fixed up my injector. Problem is now fixed so the idle was not caused by plugs or the intakes

[khoa@x-ph.com]

Originally Posted by MatRempit

Turns out that I had a leaking injector which damaged coils for cylinder 5 and cylinder 6. I have replaced the coils and fixed up my injector. Problem is now fixed so the idle was not caused by plugs or the intakes

Good to see that you found the problem and fixed it before getting any worse!