I am having a big problem with my car.
My tuner can't solve this problem

I installed AEM EMS V1 and GSC S2 Cams and AEM 3 Bar Map Sensor on my car on the same day and having this problem since

The timing is set to 107 113 just like it says on the GSC website

I recorded a video of the problem so you guys might understand it better

The problem occurs on 1st and 2nd gear and sommmmetimes 3rg gear at low rpm

Let's say I start driving in traffic, 1st gear going up to 1500-1800 rpm and hold my foot steady on the gas pedal, the car starts shaking as if there is an earthquake inside. I immediately push the clutch and start driving from 1st or I shift to 2nd. If I accelerate without keeping my foot steady at 1500-1800 rpm range, nothing happens
It does the same thing in 2nd gear too. Let's say I start driving, I accelerate and bypass the problem in 1st, I shift to 2nd and there is light traffic so I keep my foot steady at 1500-1800 rpm, the car starts shaking again. If I keep on holding my foot steady on gas, the shaking gets stronger.

This also happens at deceleration. Let's say I am taking a light turn, I am either in 2nd or 3rd at let's say 2500rpm, everything is normal. I decelerate without touching the brake, just letting the car slow down in gear. When it gets to 1500-1800rpm range, out of nowhere, the car starts to shake.

My tuner tuned many Evos, many 1000+hp cars and he couldn't figure this out. It is not a fuel related issue, it is not a drivetrain issue. My tuner first said it might be because of Gen1 AEM EMS. So we installed a Motec M800 to the car 3 days ago and does the same thing still

He says this happens because of the cams. He says they are very aggressive and when the car starts shaking, there is almost no vacuum at the intake manifold. He says that is what is causing the shaking. He said because of the duration of the cams, it creates overlap etc. (stuff I am not too familiar with). He told me to do the timing again and this time with a softer idle and it will fix the issue

Here is a video

The first shaking is my holding the gas pedal steady
The one after that is when I release the gas in 1st gear and when the car is decelerating without my touching the pedals
The one at the end of the video is me in 2nd gear with keeping my foot steady

Please help me out to solve this
It is driving me crazy


http://www.youtube.com/watch?v=tXK6b...ature=youtu.be

 

It is in the tune(not saying he is a bad tuner, just pointing out the problem lies there, it seems to run pretty well otherwise). What is your AFR and timing at that particular time?

 

well I don't know but I can check to see
would almost to none vacuum cause this like he says?

 

btw, AFR is fine when it shakes

 

It's not the cams.

 

AFR is fine when it shakes....tell's us nothing. Though I/we are not saying anything is wrong, we have to start from the basics with all the info in order to make an effort to assist.

 

does that mean exactly?

Have you checked and double checked all your timing marks?

 

Are you still running balance shafts?

If so they may be out of phase.

 

When you watch the video its actually more of a bucking, almost like an oscillation in fuelor timing or sonething of that nature

 

I will post the fuel and ignition map screenshots here
When I said AFR is fine, it is between 13-14

timing marks all checked. I actually rebuilt the motor with cp pistons and carrillo rods
so it is a brand new motor but it was doing the same thing with the old stock motor

no balance shaft
have the amd balancs shaft eliminator

 

What exactly does this mean that you set it to 103 and 113? My understanding from watching cam installs multiple times is to drop them in and make sure all the timing marks line up without changing the degree of the cam for lining up on the timing marks. My guess is this is where the problem resides, the cams are really not that aggressive and would not cause the car to drive funky like it is in your video.

 

^^this means what?^^

 

I think those #'s he's talking about are the spec of the cam as to where it sits (in degrees) when you have all the timing marks lined up.

 

Here are the screenshots of the tune in the ems
BTW, right now I am breaking in my engine so the car is only tuned to 4000rpm

Fuel Map






Ignition Map

 

We did the cam timing according to GSC's website
I have HKS Cam Gears and we set them to 107 and 113 just like it says in the link

http://www.power-division.com/produc...cat=285&page=1