Mustang Is Wild And Unpredictable, Please Help?!

chubbza5

New Member
May 4, 2017
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Hey all,
I'm new to mustangs, and Ford's in general. I've been working with a friend on his 03' mustang GT v8. It was kind of a mess when I first saw it (intake tubing with clamps missing, ripped silicone connectors, missing wiring, etc.) and I've been bringing it back to life.

I fixed the intake problems, cleaned MAF and IAT sensors, replaced plugs, cleaned heads, replaced IACV, etc. for a general refresh.

The car gained probably 40hp on the butt dyno, but now when I dump the clutch in 2nd gear, the thing kicks sideways like a branded mule. Holy sh!t I was terrified the first time it kicked sideways, it tried to kill me! I come from driving a 240sx, I have a chevy truck with a small block, and my GF drives a Z. Not even the truck feels as unpredictable as the Mustang GT does.

Here's my question... What is the part of the rear end that makes it feel so loose, and so eager to spin the car sideways, even if all wheels are pointed straight? **EDIT: It usually seems to shoot the rear end to the right, causing the car to steer left, hard.** Here's my guesses in order...
1) Rear bushings (which ones)
2) Ride height (it sits as high as my Silverado if measuring wheel arch)
3) Spring rates are too low/shocks are blown
4) I'm feeling binding, so, axle binding/ control arm problems? Is this a factory/design issue?
5) ?????

If you could give me some insight I'd really appreciate it. If there's a thread I've missed please point it out. I'm not interested in the "noob" mods, I know how a car works. I think there's something fundamentally wrong with this car (maybe it's just his). I drove a Mach 1 for a while and it was MUCH more predictable.

I have been approaching slowly and leaving the saddle on the ground, she still bucks like a b!tch though!

Thanks again, pony people.
 
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My vote is #3 plus. I would look closely at the quad shocks and the limited slip diff (or the lack of a working LSD). There are tests to check to confirm that the LSD works (I suspect it does not).

Do you have a Ford Service manual? If interested in getting a copy for yourself I maybe able to help. PM if interested.
 
My vote is #3 plus. I would look closely at the quad shocks and the limited slip diff (or the lack of a working LSD). There are tests to check to confirm that the LSD works (I suspect it does not).

Do you have a Ford Service manual? If interested in getting a copy for yourself I maybe able to help. PM if interested.
I didn't check the LSD for function. Sounds like the black line test is in order until I can jack it up again.

That quad shock is quite strange, I wouldn't be surprised if it was toast as well.

No FSM for now, I'll let him know that you made the offer though! Thanks wmburns!
 
People pay good money to get that kinda scare from their automobiles. Some folks even complain that the new mustangs are too controlled to have the mustang nameplate. The unpredictability is part of the fun.

Or it could be somethings broke too..... ha ha.
 
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