Installed ported head and JUN 272 camshafts. I also swapped out rail for Agency Power rail. For some reason the car just has a horrible and unstable idle. I thought maybe it was due to blow through setup so I used original MAF housing and reducer to install suck through setup again just like stock. Duct taped the old MAF flange shut (since I'm only concerned with idle quality it will work fine for these purposes). Cruising car runs fine but dropping down it just is unstable especially off throttle. I put in original injectors so MAF, MAF housing, injectors all stock. It has new plug and they look mint. I also swapped coils and MAF's with a friend just to make sure it wasn't a mechanical issue. The car seems to idle better when a bit rich but even with map tweaked to add fuel in idle area no go. Load is about 30-35 at idle (due to lower vacuum of the cams). Tried messing with MIVEC before but will try again but just sounds like it's popping as if fuel was running out or there was a loss of fuel pressure. Should I try installing stock rail? Only reason I got the AP rail was because I wanted a port for fuel pressure gauge and of course it doesn't even have one. Comments?

 

-Bump up the idle rpm (there's a bunch of tables, but they're obvious)
-Add some timing in the first few rpm/load cells of the timing maps (where the car idles and a little outside of that)
-Add/remove fuel from the fuel map in the same spots, might help (worth trying)
-add/remove mivec intake or exhaust, but I'd think 0/0 is where you want it.

 

Tried all that. Oddly today the tape came off the MAF hole and it idled beautifully at 13:1 but it's still unstable when bliipping the throttle and what not. THese cams do like to idle a bit richer than 14.7:1 but sadly there is no O2 sensor scaling yet through ECUflash so the fuel trims may be a bit off. I'll play with MIVEC this weekend perhaps and see what I can do with it. I've been pulling my hair out on this issue for a while now. Every once in a while it idles awesome but just not stable when driving the car and stalls constantly.

 

Set idle to 900 for now. Had it higher but didn't really help and when it is stable it idles fine at 900. Wish I could check fuel pressure easily .

 

What is your fuel system like? Do you have too much fuel pressure at idle? The stock fuel pump wiring will run at like 9v at idle and 14v when higher in revs. If you have your fuel pump wired so it sees 14v all the time, this will give you problems.

So it does idle ok at 900? Don't expect a cammed evo to idle perfectly at 'stock' idle settings, 700 is too low. Try 1000 or even 1100 if it won't play nice, at least you'll have a semi-steady idle.

What cams are these? Check the fuel pressure or pump voltage to see if what I said above is potentially an issue.


*edit* ported head and JUN camshafts. Got it.

 

Fuel pump is 100% stock. Just grasping at straws here. I've tried 1100 but it's not the idle speed. Something is causing revs to bounce around and jump up and down plus the car just sputters and coughs as if it's misfiring but fuel on the wideband and fuel trims confirm it's well within range of being able to run. I can check pump voltages. I do have new fuel pump relay in there and ran fine holding fuel pressure steady at 22 PSI (during my preliminary testing). Injectors went static at 6000 RPM or so but fuel pump was definitely working to full pressure. Oh and took spark plugs out yet again and they look clean and perfect no uneven mixture or anything else. Gap on these is fairly tight so don't think I would benefit in gapping them any closer.
It idled today perfect at 900 RPM for like a minute when it was running 13:1 mixture. Purred but it was about the only time it has done so. I've tried running it richer thinking maybe these cams just like more fuel at idle (some do) but it's not the only issue here. There's something else happening and I have no idea what it is. Also no vacuum leaks. Vacuum is about 10 inches of vacuum when idle is steady.

 

Ive got a horrible idle I just figured it was the cams. Subscribing for an answer.

PS. I am still going to get that Manifold Guru. I should be doing my install within the next few weeks

 

I had idle issues with my car when i added the S2's

I increased my BASE IDLE ISCV tables all 3 of them because the car would run with the AC on either,

I then increased my Idle in the tables, Removed some fuel, and running 10 degress of timing in idle areas.

You can also try turning of Closed Loop at idle (i may have closed/open loop wrong i get them mixed up lol)

And lastely adjust your base idle BISS

 

Wish we had the option to turn off closed loop at idle or at least target a different af ratio. Not available yet on evo x

 

EvoX dude, not evo8. Different idle stuff, fortunately (and unfortunately).

 

do you have an intake? if so, is the cone exposed? if so, touch the cone after you drive your car for a while and you'll see it is hot as ****. the ac fan blows hot air right in the direction of where most cones are and it makes it idle exactly like you're describing. i had that same issue with my ets intake until i build a shield for it. just ruling out things.

 

It is but actually turned out to be intake oil camshaft control valve. All fixed and car running VERY strong at 25 PSI. I am going to get my 3.5 inch big MAF in there next and get it to the dyno to get it dialed in and raise the boost a bit more. Hopeing for 500 WHP on pump 93 octane.

 

make sure your cams aren't one tooth off.

We had a car with the intake cam one tooth off and it would not idle
Fixed that and BLAM perfect idle

 

No double checked the chain initially and all was perfect.

 

What was actually wrong with the intake oil camshaft control valve?
Was it just unplugged?