I experienced hesitation when on WOT boosting beyond 1.25bar when I set my EBC limiter on 1.20bar problem disappeared. I also dynoed the car and noticed the graph at top end was rollercoaster like, up down, up down etc.

Anyway, problem was the the fuel pump was not feeding enough fuel for my mods so I upgraded to the pump and problem has gone, boosting 1.2bar and above with no prob and dyno now looks good.

Should have upgraded my fuel pump before my mods went in.

 

I have this hesitation problem once in a while. It happens at mid to low rpms. Power is definitely lowered and the car flutters. The car also throws out smoke. If i coast and wait a minute, it just goes away. I put enough toluene in the car to raise the octane to 94. Still does it once or twice a week. I am very interested in someone with the same problem diagnosing it.

Thanks!

 

I had this same problem (previous post) and tried installing new plugs, only to find that copper plug people had recommended didn't fit the IX. Oh well, so I put the OEM Iridiums back in and the 4k flutter/hesitation hasn't been back since. Dunno, it was either a fluke or a funky connection somewhere that had an electronic harmonic with 4k rpm. Removal and reinstallation cured it for me.

 

just bought a new IX, it literally did it pulling off the lot brand new with 1.2 miles. I now have 1800 and it's still doing it....bad.. usually in the morning when i first start the car, let it warm up for 30 secs pull away and can't even get started... hesitates horribllyyyyyy,

 

i have a similar problem as atlvalet...i'll run her WOT and each time i run WOT it sounds and seems as if the boost is lost even though the boost guage reads perfectly. but, when i let off of the throttle and press it again, the boost comes back and resets. i'm running a hallman MBC and a Greddy type RS BOV. i wonder if it is the BOV or if there is a leak elsewhere i'm not seeing? any help or advice would be appreciated thanks!

 

my car seems to be doing the exact same thing. the thing is, i have no turbo. right around 4K rpm it kinda stumbles and may or may not do it again before redline. does it in hot as well as cold weather. tried new plugs, wires, and coils. would stop for about a day or two then come right back. started in jan 05 and the car has sat for about a year while i replaced and upgraded MANY parts. but it still does it now. i have checked almost every possible thing i can imagine and to no avail. i am at a loss and all of your problems seem all to similar to mine. any insight would be appreciated.

 

Mine started doing it two days ago. the car runs fine until it hits about 4800 rpm then it bogs for a second after that it runs fine. Only engine mod is a drop in filter. Wtf?

 

You need to explain it better. I highly doubt it "bogs" at 4800rpm. It either sputters (plugs), slips (clutch), hits a brick wall (fuel cut), loses all boost while whistling and doesn't boost again until you let off the gas (intake snorkel syndrome). Yeah, there could be some other random, strange things, but for the engine to actually BOG requires an overload of traction without enough power to accelerate (like launching from too low of an rpm). That doesn't happen when accelerating through a gear, though...

 

I used "bog" since that kinda what it felt like (old 4v carburator days ). Its a smooth hesitation lasting about what feels like a second. Everything is normal until about 4800 when the car feels like its dragging somthing, not accelerating but not slowing down either. I first noticed it gassing it on the onramp going though the gears. Same RPM each time . Cruising in 5th, it happened again passing another car with no shifting and constant throttle. It still reaches redline but not after a "hiccup" . Random? I hope. I looked over the engine and didn't see anything obvious. The car only has 12,000 miles and everything is still pretty clean. The only mod is a drop in filter. Warranty time i guess. Any Ideas Warr?

 

after reading other posts online i decided to check my BOV, and gues what? the damn thing is the problem. however many said that the spring was the problem. on the greddy type rs BOV check the rubber seal. that's where my problem was. a cheap and quick solution to the problem would be to patchit up with some other type of rubber. I used some rubber cement, the same kind you use to patch up the inner tubes on a bicycle, and a small piece from a latex glove (powder free) big enough to cover the ripped up seal. just treat it almost as if you wereback to the basics of running with the 2 wheels and pedal action and you should be set. after I did this, my car has been running beautifully, full power and full boost. you can pick up some rubber cement at just about any wally world, just look around at the bike stuff and you should run across it, hahaha!

 

a friend of mine described something like that to me when i was asking him what having engine knock felt like...well nevermind..just read your last post, i guess you figured it out.

 

I now have this problem, could it be a slipping clutch??? When ever I go WOT or near WOT at anything abover 3000RPM, my revs hesistate and drop about 500RPM and then continue all the way to redline no problem. For example I'll go WOT at about 4,000RPM and then the revs drop to 3,500 or 3,600RPM and then climbs towards redline with nofurther problems? Is this a slipping clutch or am I pulling timing?

 

I don't think it is the clutch now after reading slipping clutch threads, the car still accelerates, but it not only hesitates, but it also drops 500RPM or so and then continues on with no further problems.

 

It doesn't sound like a slipping clutch... if the clutch slips, the RPMs will go up but the car won't accelerate, and it won't be a sharp or sudden sensation.

Do a boost leak test first.

 

has anyone ever thought it could have absoutely nothing to do with boost? it seems i am having the same problems and i have no boost. maybe this can help narrow it down. also noticed my problem has gotten severly worse. instead of just one or two misses in high rpm, it sputters badly and will not accelerate until i let off the throttle. so basically it will not accelerate whenever im at 3/4-full throttle. will also miss once or twice in low rpm if im in too high a gear.