When I try to keep a steady speed, the car jerks back and forth

[Render]

Okay ive had a 91 GST for a couple weeks now, and its been doing this since I got the car, I never really thought anything of it till today, then I realized it could be potentially dangerous for me or my car.

When i accelerate. Wee. When I try to keep a steady speed, the car jerks back and forth. I dont really quite know how to explain it. Maybe you know what im talking about.

 

[Aikouka]

When the car jerks, do your RPMs go up or down?

 

[Render]

it just kind hops back and forth like the car... back (up) forward (down) ... some things that MAY affect this or be affecting it...

My steering wheel jitters and any speed

My car idles crazy as hell, when it first starts up with ROARS to about 3000rpms and stays up at about 2000 till it warms up and from there is random at what it is at, some days ill be at 500rpm's and almost dieing, and some days ill be at 3000rpms sounding like im flooring it in neutral. :-/

 

[Aikouka]

Well, the I'm no expert, but the first two things I thought of were the clutch beginning to slip or a cylinder not firing.

If your clutch was slipping, first your RPMs would go up, and it'd feel like you were in neutral, then when the clutch finally re-engages, the rpms would go back to normal for that gear/speed and the car would most likely lurch.

If a cylinder wasn't firing at some points, the car should drop in RPMs when the cylinder doesn't fire and then pick back up when the others begin to work. This WILL cause lurching, because my mom's van had that problem (it was just the ignition coil.) Usually if a cylinder isn't firing, the car will backfire, though.

The car shaking could be from bad alignment, bad tires or bad mounts.

 

[Dark Syde GS-T]

install a A/F meter and watch it by any chance is your mas hacked if so get a new virgin mass because this problem happened to me when we over hacked my mas with no SAFC to tune the car ran real quick at acceleration but cruise it jittered and stuttered because the car was not tuned for the mas being hacked to the point it was. just a suggestion

 

[PoorDLBoy]

Check for a vacuum/boost leak. I might have gotten what you are reffering to back when i was venting my cbv. It would happen around the 0 boost mark (or lower).

You are meaning a really violent shaking, right. My steering wheel also shakes, but i think he's referring to something more violent.

 

[Render]

no its not really voilent, it probobly goes about .5 inches (the steering wheel)

as of yesterday i hooked up the stock boost selenoid and im running 10psi according to my Autometer Phantom boost gauge...Isnt that low? Im asking this becuase PoorDLBoy suggested vaccume/boost leak.


And I think im going to try and get an A/F guage real soon

 

[4G63 GST]

Are you by change venting your bov into the atmosphere? .. if so .. and your bov isnt crushed or aftermarket thats probably your problem.


Luke

 

[Render]

Hmm...Accually I am venting I love that sound. Ill re-hook it up and see if that helps. Luke, could you check my other post:

http://www.dsmtuners.com/forums/showthread.php?p=1147702

and tell me if recirculating may fix that? Thanks!!

 

[4G63 GST]

My bov wasnt crushed at first and when i vented it ran like crap. Unless you plan on crushing your bov .. you cant vent with out idle problems.

Luke

ps.. dont know about the emissions problem

 

[Render]

Yea i might sell the car, so i dont plan on modding the car, the car idles like a pile of sh*t anyways, weather its vented or recirc'd when im just idling, idk about when im driving though

 

[4G63 GST]

more than likely its a simple boost leak in the car.. its just finding it thats the problem.


Luke

 

[GSXlaunch]

Check the two connectors on/near the ignition module...you may have some fluid in there or the connection is loose. I had the same issues and it turned out this connector was loose. It made the car jerk back and forth and my idle was shot to hell.

 

[Render]

Wheres that?