yesterday i was on the freeway with no traffic so i decided to give my car a little exercise. I jumped on the throttle at about 55mph... the car was in Wot and as it accelerated,but then i felt the car stutter for a split second. It almost felt as if i took the car down to about 80% throttle for less then second then back to100. It still reaches full boost at 15psi but just around 8 or 10 psi at WOt is where i feel this....



Anyone know what this could be? Is it the turbo? fuel?bov? any help would be appriated. thank you

Any codes? Check your ignition system, you might need some new plugs, wires, cap, rotor, etc. Also make sure the engine grounds are tight (the one that bolts to the bottom of the manifold, in particular.).

-Doc

you got knock response. lower your boost.

this whole "15psi is ok" that we get from the usdm mr2 guys, doesn't always apply to our swaps because we have jdm ecu's with more timing advance. we have a harder time running that much boost on pump gas.

if you make yourself a tvsv led's, you should be able to see when this happens.

Great thanks guys this is a good start... We'll see what cures it. thank you!


Edit: would a faulty BOV cause this too? i have an hks ssqv.... it was just a thougt i had that maybe its opening up for a second and bleeding boost for that moment only... is there any way to check that?

This post has been edited by eggman40: Dec 31, 2006 - 6:36 AM

Yeah... do a search here for "boost leak detector" and check that out.

-Doc

the HKS is VERY sensitive, and can open a little bit at slight throttle changes. but if thats the cause of it, you should be able to hear the bov leaking and be able to tell right away.

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If you are running JDM ECU`s then i`d agree with this...Japland pump gas is 101ron...you need to be running at least 98 ron to help prevent knock.....or get yourself a UK ECU which should let you run 95ron with no problems what so ever.

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shoot... i wish i had 95 here in cali we're only allowed 91... BS! anyway, do you or anyone know if the UK ecu is plug and play? or would it cause problems?





second--- I dont remember right now it i heard air leak like you said Lagos... ill try again tomorrow and see if i hear any kind of air leaking...





3rd--- thanks doc ill look into that and hopefully get one built next week.





Thanks again guys for all the help !

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I second that motion^^^^^^ I just did these last week and they are very nice to have to let you know more vital signs on your engine

>The 91 octane we get here is approximately equivalent to 94 octane in other countries. They use RON, we use (RON + MON)/2. The 98 octane in Japan is more like 94-95 octane rated in the US. Most ECUs can figure it out with the knock sensor, but there may still be a bit of hesitation (my gen 3 motor seemed pretty happy on CA 91 octane gas at stock boost).

-Charlie