Post Stillen Supercharger Issue (Jerky Driving)
 

Post Stillen A2A Supercharger Issue

Hey guys,

So I just wanted to explain an issue that I am having to see if anyone else has experienced this and if so how the bested the issue.

1. A jerking and bucking sensation in all gears when normal driving, light acceleration pedal action.

2. More so when attempting to calmly drive uphill.

3. Car lost all accelerator response and got the P1239 CEL(TPS) twice now.

4. Bouncing idle, anywhere from 18.0-11.0. It will hover in the 14.7 area and these randomly bobble back and forth to lean and rich.

5. Cold starts in the morning are terrible, car will attempt to turn over, sound like a cammed v8 and then die, unless I mash the accelerator that is, it will fire up fine then. (I believe this to be a cold cranking MAP and not related to the above, maybe)

6. When going highway speeds+ I get the same jerky and bucking feeling, and sometimes my car will actually randomly like kick as in picks up a bit of speed.

7. Sometimes when starting from a stop (redlight etc...) it feels as if I have a super delay in power, the car will move but not like it should, and then it will all of a sudden kick up to the right power.

8. Lastly, this may not pertain to the main issue too but when I pull in a parking lot per say, or my drive way in 1st gear and let out of the clutch and gas the car will start to intensely buck back and forth like it can smooth itself out.

I have ordered the newly revised Stillen extension cables in hopes that they fix my issue. Any other advise would be greatly appreciated!!

Thank you :tiphat:

Make sure that you've got the right cables plugged in to the right spots. the cables and connectors are identical for the MAF and the throttle body with the exception that one has 6 wires and the other as 5. I did this when I first started the car up and had the same issue.
Also, rev 1 and 2 of my tunes were pretty jerky, so a revised tune might clear that up.
I've noticed that my car has been a little jerkier lately since that arctic front came through, so maybe that has some play in it

I didn't think cold could affect drive-ability like that, at least once the car is up to operating temps. I will insure the cables are in the correct spots.

You're most likely right. Unfortunately in the current weather conditions (before the snow and ice) my daily drive gets me to normal operating temp just as a reach the final 25 mph leg of my trip :(.

Oh man, so you are cold the whole commute :O
Better wake up earlier to start her up before you leave haha

Did you go from the water cooled system to A2A? If so you MUST retune. Seb is the answer!

Yeah I have been A2A for a few months now, tuned by Jon @Z1. 504whp. He says the tune isn't the issue that it is electrical or mechanical.

Smoetimes I think about taking a highway exit to take the "scenic route" in the mornings haha.:driving:

Anyone else have any advice on this?

Definitely get the new Stillen harness in the car and then relearn the TBs. I recommended wrapping them with foil as well. Seen this many times come through my shop.

I had a loose front timing cover sensor once after goofing around with my 350z. It acted just like this. Check all clips to anything controlling timing. There's two on the face of the motor, right by the sc bracket. One might have gotten slammed when putting the bracket back on. Look at your vvel clips too.

Timing cover sensor as in cam pos sensor?

That's it.

I have that same jerky driving under light load, I either end up gearing down and lugging it a bit or gearing up and running it a bit higher than I would when I'm cruising , I can power through it when it does it, my tuner noticed it in his drive home and tried to adjust, but it still does it. Only after the a2a we had this problem. Are you uprev? I've sense bought a ecutek cable from seb thinking that will be my solution but winter came before I could datalog.


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Yes I am using UpREV, after you go ECUtek let me get some feedback! I have thought hard about it.

I hope we get a solid resolution on this problem! Please report back what you find!

In an effort to think outside the box, I'm wondering if those without catch cans might be more susceptible to this issue in a FI engine? Fouling of the throttle sensors?

It feels like something either tricking the TPSs or they are getting an incorrect or fluctuated current. But I could be way wrong :/

Do you have the new Stillen extension cables?

I also had this problem recently...it happened to be my pins on MAF1 going to Bank 1, right at the end of the pig tail. Apparently when using the Stillen Extension Cables on the original Stillen set up (A2W) it had widen the gap on the original MAF harness pins under the pigtail. Due to the new piping I only used the Stillen extensin cable on one of the MAF sensors (Bank 2). After straightening out the pins I was back in business. The loose/misaligned pins on the MAF pins was tripping out the MAF readings thus throwing the AFR'S and Idle.all over the place.

I have spare sets of Brand New Gen2 Stillen MAF cables. Just FYI.

After A2A you only using 1 extension? I am still using 2?? One to the upper MAF and one to that Throttle body.

Also guys, another reason I am thinking may be a vacuum leak. Anyone know a good way to do a vac test with the A2A setup?

smoke test should work or while idling spray carb clean/ brake clean around

I plan on spraying my TBs and Manifold just to make sure, but Im still trying to figure out a way to smoke test the system. I would have to plug the BPV and the SC inlet no?

Id test the Maf sensors too. The gasket can easily get crimped and cause a leak. Ive seen it a few times already, including my own build once.

You dont have to use smoke. Just use pressurized air. I can send a pic of the adapter to build for like $5. Then just clamp it in where the L pipe clamps into the Tial pipe and pressurize it to about 5 psi. You need to make sure your at TDC (top dead center).

Yes please send me some info on this! :tup:

And referring to the MAF gasket...... I am actually missing a MAF gasket completely on one of my MAFs...

Lol...Wellllll.....

I don't know why I didn't catch this when installing the MAFs I don't think this will cure my issue though

Update: Had a spare MAF sensor so I just got the gasket from that one, no change in drivability. Still super jerky under light throttle load.

My new stillen cables will be delivered this afternoon, hoping for good results! If not I am going to get the CJM fuel return system and see if swapping out the pump along with it cures the issue.

Yeah mine was thoroughly Checked for leaks, I only used the one extension cable as well, and it's the new updated one. My thoughts were because it's only during a light load, that it's the bov opening up a little and confusing the mafs? That's why I was thinking sd tune would fix it. Be a couple months before the snow melts before I find out :( unless you figure it out first! Haha. Btw, did yours get worse as you drove it from initial tune? When I first picked it up my tuner was the only one that noticed it on his drive home, 2 months later I noticed it once, 3 months later it did it in every gear. Rechecked for boost leaks, holds 15 lbs with no leaks. Sadly no boost gauges or afr gauges yet to see if anything goes weird during issue.


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Yes it actually has gotten worse since then. But I've been datalogging and adjusting the tune with Jon at z1. Nothing helps

My tial doesn't close until high rpm range, so it couldn't be that right? Since that's not a light load lol

Update: Installed the new Stillen cables, wrapped it aluminum tape. Didn't fix the issue.

Jon@Z1 say he can see the issue from my datalogs and is going to connect via teamviewer later on and watch the issue more closely. He says the he can fix it, even if the BPV is messing with the MAF.

My tuner could see it as well, made adjustments but didn't seem to help. Atleast you have the best uprev tuner working on yours, so if it is a tuning issue, he will fix it.


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I will keep you updated, he says he is able to trick the MAFs. Fingers crossed!

Update 1/13/18: So Jon and I drove around for awhile, while he did live tuning. He could see every single jerk and jump as soon as it happen and he adjusted and smoothed them out section by section of the throttle load.
As you guessed, the Tial BPV is causing some of the jerks, right at the point were it closes/opens under light load, confusing the MAFs. He was able to trick the MAFs in that area though to help the jerking. The issue is about 90% better, SD I would say is the only way to 100% the issue.

In short, if your uprev tuner is good, they should be able to smooth everything out for the most part.

Kinda figured as much! Glad you were able to smoothen it out for the most part!


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Due to the fact the jerking still exists, I will probably be making the switch to ecuTEK.

could you switch to recirc valves and solve the issue as well?