couple things needing addressing

[tmosser]

:hi:

I just had a couple questions/concerns about my evo ix.

First off when I first start it and let warm up is it normal for the afr's to be rich at first (10's) than gradually increase to 14.7/14.3 flux once warmed up?

Than secondly, This problem has exsisted since I bought the car.. Whenever crusing at a steady speed (usually happens at highway speeds) if I give it more throttle to merge or pass etc. than let off to 1/4 or very light throttle it will start jerking and go piss rich. untill I give it gas again.. Ive looked over all lines etc just cant find out why. I went back to a perrin intake (uses stock maf scale) and that didnt fix it. Its just really annoying when Im driving somewhere and everytime I try to let off the gas it starts jerking. I get the "WTF is your car ok" look alot from passengers.

It is tuned by shane, but I plan on getting a retune for e85 sometime this spring since my e85 tune is quite old. (currently on a pump gas tune also done by shane last march)

mods,

perrin intake/perrin foam filter
megan o2 housing
dc test pipe
greddy ti-catback
pte 1000cc's
wally 255
crushed ix bov (did it even when it was un crushed)
nesei licp
ams fmic
ams mbc
Pretty much it.

If anyone is in the mankato area I can show you what im talking about.
Or I will be in shakopee tomorrow afternoon

[mdost03]

Probably needs a retune I would think.

[tmosser]

See thats what i thought but this pump gas tune Im on was done in march... Who knows if i can't figure it out hopefully shane can when i take it to get tuned on e85

[goodhart]

Does the bucking happen in a high gear and low speed? Ex: 5th gear, 50mph

Another thing: When I had mine, I switched from a Injen intake to a Perrin and the car was running a good deal leaner at WOT (12.1 vs 12.6).

Did you change the intake before or after the tune in march?

[tmosser]

No usually happens when its around 2500 rpm and up will do it in any gear.

Yeah changed intake after tune but MAF scaling was stock already so nothing had to be changed.

Note it did it with both intakes aem and perrin so i don't think its related to the intake. It needs a new filter though, previous owner had the damn foam filter just laying on the acd resavor so it got mighty dirty and ripped on the bottom side from rubbing and being pressed up on it... Tisk tisk

[goodhart]

That ACD reservoir is a pain in the ass always rubbing on filters

[tmosser]

With this perrin intake it don't. I was even able to mod the stock air box to fit over the perrin intake and filter ;) looks nice and stock.

[19TsiAwd90]

is your bov vented to atmosphere? if so, that could be your issue. like when you get boost up to 0 and let off a little the bov opens, and stays open cause there is no pressure/vac shutting it. all that metered air is getting dumped, causing pig rich jerking/buckin

[scheides]

^good call on the VTA but the perrin intake is setup for recirc.

The part about AFRs during warm-up is 100% normal and expected. AFRs will be rich until the o2 sensor and coolant temps fully warm up. 10's seems excessive, maybe there's a way to tune that, not sure.

The bucking issue you are describing plagued me in my evo8. It is horrible and I fucking hated it. Three things helped me:
-having the BOV away from the UICP (like stock), not directly mounted on it.
-Greddy RS valve -> Evo IX valve
-Speed Density conversion. Some people see no change but go read the posts I made, I fell in love with the car all over again.

Also, basics basics basics. Clean your MAF (carefully!), check for boost leaks, check timing, engine health, etc.

[tmosser]

Thanks for input guys!

I have the crushed IX valve it is right on the perrin intake with stock tube going to stock uicp.

I am thinking of going to SD i actually want to.

I noticed when i let off to part throttle the afrs go very rich which where it starts gurgling and studdering.

I have done boost leak tests and every time i change oil i look over everything i can and everything seems fine. I hope a SD conversion cures it. Can i use stock bov for SD? I wanna keep the stock look (don't want to replace stock uicp or could i use a small hose and mount something like the tial on it?

As weird as it is sounds like bov because when it studders the bov goes into sneeze mode and goes nuts until i give it gas.