Car shakes when driving after tune

[RyleeST]

So, I recently bought the Cobb Accessport V3 directly from Cobb and I flashed the stage 1 93 octane tune on my ECU. At first it seemed fine and I loved it. Recently, though, I've noticed my car shakes quite a bit and I'm wonder what could be wrong. It gets worse at higher speeds. I'm wondering if I shouldflash the ECU back to stock or go to the 91 map and see if it's better.

My car is bone stock except for a blow off valve spacer and the tune. I'd love some feedback.

EDIT: I am not 100% this issue is caused by the tune but it did start happening just a couple days afterward. We also just got a bunch of snow so maybe there's some stuff stuck in my wheel arches or something that I've missed. I don't think fuel should be an issue unless the gas stations around me are doing some sketchy stuff with their octane ratings.

 

[FiestaSTdude]

Is this like a engine stuttering shake or a suspension shake?
I would jack the car up and feel your wheels for any movement. Also inspect the tie rods and struts to make sure they're in good shape.

 

[LiLfieSTa]

you said you flashed to 93 but wondering to reflash back to stock or 91

did you fill up with 93 or 91?
Im not sure if thats the factor, but just curious

 

[Pablo Pistoffo]

You could probably narrow it down some if you got a better handle on when and how it shakes- only under acceleration, or under different types of engine load? What happens if you are at speed and push the clutch in? Any codes? Does it happen when turning, or going straight, or all the time or...?

 

[thecman02]

My bet is you had an ice chuck in one of the wheels causing a nasty imbalance.

 

[XR650R]

My bet is you had an ice chuck in one of the wheels causing a nasty imbalance.

Yeah. It doesn't follow that a tune would make the car shake. Didn't you just get a lot of snow in Terre Haute?

 

[FiestaSTdude]

My bet is you had an ice chuck in one of the wheels causing a nasty imbalance.

That could be it. He described it as worse at higher speed, which is how my wheels felt when they weren't property balanced. Hopefully it is something simple like that

 

[Pablo Pistoffo]

That could be it. He described it as worse at higher speed, which is how my wheels felt when they weren't property balanced. Hopefully it is something simple like that

This is a really good point- loosing a wheel weight, or getting packed in stuff like snow or (if you rallycross) mud can make it shake like crazy.

 

[SrsBsns]

My bet is you had an ice chuck in one of the wheels causing a nasty imbalance.

Reminds me of My Cousin Vinny where they get stuck in the mud and it throws the balance of the tires off.

 

[M-Sport fan]

This is a really good point- loosing a wheel weight, or getting packed in stuff like snow or (if you rallycross) mud can make it shake like crazy.

Competitive rallyists actually mount inboard mud/gravel scrapers on the insides of their rear wheels because of this.

 

[RyleeST]

Update: I think this issue was resolved. I think there was some imbalance because of snow/ice. I'm keeping an eye on it but now I've got a new mystery to solve. The car stalled out on me twice yesterday. Both times I was idle in neutral and the revs dropped from 1K idle to 200 and it stalled out. Any thoughts? I'm wondering if I need to be looking at spark plugs, fuel pump, air intake valve or something like that.

 

[sonicmn]

Update: I think this issue was resolved. I think there was some imbalance because of snow/ice. I'm keeping an eye on it but now I've got a new mystery to solve. The car stalled out on me twice yesterday. Both times I was idle in neutral and the revs dropped from 1K idle to 200 and it stalled out. Any thoughts? I'm wondering if I need to be looking at spark plugs, fuel pump, air intake valve or something like that.

Did you just fill up with fuel? - I ask as the Fiests ST's tank vent system does not like it when you "top up" the tank after the auto shutoff on fuel pumps turns off. Just stop after the first time it shuts off. otherwise it will run pretty rough for a while or stall until it clears the fuel from the evap system.

Any codes pop up or check engine lights?

 

[FiestaSTdude]

Did you just fill up with fuel? - I ask as the Fiests ST's tank vent system does not like it when you "top up" the tank after the auto shutoff on fuel pumps turns off. Just stop after the first time it shuts off. otherwise it will run pretty rough for a while or stall until it clears the fuel from the evap system.

Any codes pop up or check engine lights?

The best way I've found to fix the stalling after filling up is a drive around in 5th or 6th gear for a few minutes and them it's fine (until you fill up again). Mine normally doesn't stall completely, just idles poorly.

 

[FiestaSTdude]

Update: I think this issue was resolved. I think there was some imbalance because of snow/ice. I'm keeping an eye on it but now I've got a new mystery to solve. The car stalled out on me twice yesterday. Both times I was idle in neutral and the revs dropped from 1K idle to 200 and it stalled out. Any thoughts? I'm wondering if I need to be looking at spark plugs, fuel pump, air intake valve or something like that.

Sounds like your purge valve could be going bad. Like sonicmn said, check for codes, when my purge valve went it threw a code.