MitsuJDM

iTrader: (6)

This just started tonight. I did a quick 3rd gear WOT pull and I didn't have my eye on the boost gauge, didn't really think I'd have to. When I went WOT, I felt a hesitation. Not like a misfire hesitation, but it was like the car didn't have full power, shifted to forth it was fine. I didn't think anything of it, figured it was just a little quirk.

Later, I got to thinking about it again. This time I did a second gear pull. It did it again. So now that I know it's doing it fairly consistently, I do it agin. This time I watch my boost gauge. It's supposed to spike to 25psi. It only spiked to 20 psi and holds. Shift to third and it spikes 25psi perfectly fine and holds.

I checked most of the vac. lines, all the charge pipes for loose couplers, so I don't think it's a boost leak. I think it's either ECU related or boost controller related. It almost feels like a clutch slip, but it's not. RPM's don't jump. It just doesn't want to be at full boost right away.

The car does have an EPM o2 dump on it. The dump was on when I bought the car, so I doubt that is the problem. You can FEEL the power differance. You do a 2nd gear pull and the boost will spike 20psi and then half way through 2nd it'll spike back to 25psi and you'll feel a rush of power. Shift to third and the problem is gone. It seems like it's only happens in the gear you start the pull in. I only tried 2nd and third gear pulls. It's late and I'm tired. I looked around in the engine bay for obvious issues but didn't find any.

Boost controller related? ECU cutting boost for some reason? Any ideas for me to check tomorrow?

I just ordered an intercooler so once that goes on it's going in for a tune. Maybe it's because I'm slightly untuned and the weather is getting cooler? I put on an LICP and changed the intake about a month ago (already tuned for an AEM, I put on a Perrin). So I'm untuned for those two things but the cars been driving perfectly fine until tonight.

Also, I've noticed a hint coolent smell. I think there is a slight leak in one of the water lines into the turbo. Not a big deal. Seems pretty small. Though tonight I smell it a bit more than usual and tonight is when this problem started. I'm sure it's seperate from this issue, but I figured I'd throw it in there

sparky

iTrader: (1)

Get a tune! It may be fuel cut. So, install your new IC and then get a tune. Drink a few 5.2% brews and relax.

EDIT: Please don't joke about your mods or your power numbers.... get serious.

MitsuJDM

iTrader: (6)

You cannot see me pee online? What?

I was thinking it was either boost or fuel cut. It's just weird it's never done this before until tonight. I've honestly never experienced either of those, so the feeling is new to me. I'm hoping that's the issue.

And my fake numbers, I don't think anybody would take them serious. They're obviously intentionally wrong. I mean damn 15.3 @ 137mph? Haha. Real ones will be up within a month I'm sure... power numbers anyway.

sparky

iTrader: (1)

It is probably fuel cut. A drastic change in ambient temps and humidity can cause it. Since you will be upgrading the IC...then first do the install and then get your car retuned.

bbyevo8u

iTrader: (14)

ive been having the same problem as you for the last two weeks, i just got around to doing a boost leak test yesterday and i found a really big one coming from the TB seals it wouldnt hold more then 10psi before leaking like crazy so i'm ordering new seals and im hoping it will fix the hesitation.

do a boost leak test its a must!!

Evoryder

iTrader: (55)

^ just was going to recommend, might as well knock it out after you install the intercooler.

FTS EVO

I had a problem like that but it would stay in 20psi range the whole time and it was suppose to be at 25psi and never could get it to go up. Did all kinds of things and finally got tired of it and put a manual boost control on it just to see if it would fix it and cleared it right up. So for now Im going to leave it on intill I plan on messing with it again. But if you can get your hands on a manual boost control, you can try it and see if it helps, that should help figure out the problem maybe or maybe put you in a direction.

MitsuJDM

iTrader: (6)

I could do a boost leak test, I just don't have a tester. But, the thing it, it will eventually reach full boost in the next gear, it's just having an odd hesitation in boost. I'd think if it was a leak, well a significant leak, it wouldn't reach full boost ever.

TB seals sound like a possibility though. From what I read 05+ has more issues with bad TB seals according to MIL.Spec. Makes sense... My '03 Evo never had boost leak problems, but I have an '05 now, so maybe they're bad.

If I can find somebody with a boost leak tester I'll give it a try

MitsuJDM

iTrader: (6)

I already have a MBC.

I went ahead and just ordered TB seals and a new TB gasket since they're so cheap and they look fairly easy to install.

I was close to just getting a Mil.Spec or WORKS ported TB, but I can't swing that just now. Plus, pulling the IM off to port it. Too much money right now.

Hopefully I'll make some decent power.

My last Evo made 301whp at CBRD with BR TBE, 269 cams, cone filter, ETS FMIC, ETS LICP, 24psi, and other minor bolt-on's.

This Evo has AMS TBE, comp 280's, Perrin intake, ETS LICP, AMS FMIC (when I get it), EPM o2 dump, Evo IX turbo, ported manifold, etc. at about 25psi. We'll see if I can't make 330whp+ at CBRD.

Evoryder

iTrader: (55)

Or just make one yourself...do you own a air compressor? or bicycle pump?

MitsuJDM

iTrader: (6)

Yes, I have an air compressor. I think I might know of some people who might already have a boost leak tester, or I might make one.

Evoryder

iTrader: (55)

https://www.evolutionm.net/forums/ev...ster-pics.html

MitsuJDM

iTrader: (6)

I just drove the car again and even though it's a bit warmer today than it was last night it's still acting up. This time the boost seems to be a bit more steady, but now instead of the problme going away after one gear it still is present in the next gear.

I'm leaning towards a boost leak now. One that's small enough for the turbo to make up for, yet still presents a problem. I'm going to double check all my couplers, TB seals are ordered, and once my FMIC arrives, it's tuning time. I might throw some new spark plugs in just for peace of mind.

Evoryder

iTrader: (55)

How is boost controlled?

MitsuJDM

iTrader: (6)

Black Hallman MBC

Like I said, I'm going to put on the FMIC, TB seals, check all my couplers for lose connenctions/holes and possibly put in some NGK BPR8EIX and gap them to .025, spark plugs have helped my solve an issue similar to this before, but that felt more like a misfire problem where as this feels more like a boost type problem, but we'll see.

One thing I was thinking it could be is my LICP/J-pipe coupler slightly touches my dump tube. I have the dump tube double wrapped with heat wrap twice but I'm going to double check and make sure I haven't worn a hole through the coupler... I'm thinking not, but it's defiantly a possibility.