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-   -   3k-4k hesitation 01 nbb (https://www.miataturbo.net/engine-performance-56/3k-4k-hesitation-01-nbb-43040/)

Jfornachon Jan 18, 2010 06:17 PM

3k-4k hesitation 01 nbb
 
As the title states I am having a interesting hesitation or stumble when cold. I will accelerate when it gets around the 3k range it just boggs down then when it is a round 4k it takes off like a raped ape. I am still na at this time. I have changed the plugs, wires and cleaned out the throttle body. Neither of these have done any good. I am shure it has not hurt but there has not been any change.

I am thinking it may be a sticking EGR valve that is causing this issue. Has anyone had this problem? If so was it the EGR or was it something else.

Thank you in advance for any help that yall can give me.

Have a great day,
Jared

jeff_man Jan 18, 2010 06:30 PM

it's vvt and warm up mode. my car has been doing it for years. i capped my egr a few months ago and it's the same it has been.

idle to 3500 is boggy and feels like it's having problems then 3500+ all power. once the car get to about 145*+ it stops

y8s Jan 18, 2010 07:16 PM

VTCS, not VVT. it switches over at 60C.

if you look under the throttle body, there's a green one-way valve on a vacuum line to an actuator. pull that and plug it and it'll leave those VTCS butterflies open all the time.

Jfornachon Jan 18, 2010 08:19 PM

Jeff- My car is the same cold and hot below the 3kish mark.

Y8s- If I remove the line and cap it will it set a code?

I got a recless driving ticket the other day partially due to this. I think the other part is my lightened flywheel. I think the combination of both makes it exagerated. I was turning left from a stop and it surged and the back tires slid.

Have a great day,
Jared

y8s Jan 18, 2010 11:00 PM

are you running the stock ECU or something else in parallel?

maybe you have a bad water temp sensor?

Jfornachon Jan 18, 2010 11:15 PM

Y8s- The car is still stock ECU. I need to get the proper wireharness for my Adaptronic, but first I need to either sell the harnes that came with the unit that I got from Stein or the whole unit.

Have a great day,
Jared

Jfornachon Jan 19, 2010 05:54 PM

Y8s- It looks like that cured the problem. Thank you.

I wonder if the lack of power on warmup has any thing to do with the recall thatwas performed. If I remember right people were complaining about there beeing a lack of power after it was performed.

Have a great day,
Jared

y8s Jan 19, 2010 06:12 PM

those butterflies should open all the time once the car is warmed up. if they're closed, the car will have some crappy low end.

Jfornachon Jan 19, 2010 06:35 PM

That's exactly what it feels like. It still picks up around 4k but it is a smother transition now.

Have a great day,
Jared

jeff_man Jan 19, 2010 07:26 PM


Originally Posted by y8s (Post 509929)
VTCS, not VVT. it switches over at 60C.

i know the vtcs stops being lame after warm up but doesn't the vvt moving while vtcs is in warm up add to the power jump?

y8s Jan 19, 2010 09:19 PM


Originally Posted by jeff_man (Post 510387)
i know the vtcs stops being lame after warm up but doesn't the vvt moving while vtcs is in warm up add to the power jump?

on a stock car, it's only a few hp. the VTCS is more like going from 5% throttle to 100% throttle.

Jfornachon Jan 20, 2010 05:53 PM


Originally Posted by y8s (Post 510428)
on a stock car, it's only a few hp. the VTCS is more like going from 5% throttle to 100% throttle.

That is exactlky how it felt. Since I have pluged the line it has not acted up. Has anyone figured out why this happens? What part would fix this problem besides just pluging the line?

I am sort of ocd about the car opperating as designed but I want more power. I know this is very contradictory but that is how I am. Thank you to all who have helped me out in the matter.

Have a great day,
Jared

y8s Jan 20, 2010 07:31 PM

Someone mentioned it might have been part of the factory ECU recall... leave the butterflies closed even when warm. that's silly though.

anyway, it feels like you go from 5-100% throttle because they basically ARE throttles.

Duckie_uk Jan 22, 2010 04:05 PM

You could go the extra mile and remove the butterflies & shaft altogether and profit. Not sure how much power it would be worth but if Braineack went to that much trouble to thin down his throttle shaft (which then lost a screw with amusing consequences) then it must be worth totally removing a restriction in the runners like an inoperative VTCS system.


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