Car falls on it face at 70mph

[USCGunner]

My 91 5.0 auto trans has great pickup until I hit 70 mph then it falls flat on it face. Any suggestions I have replace plugs, wires, cap and rotor. Stock motor only mod is a cold air intake.

 

[a91what]

My 91 5.0 auto trans has great pickup until I hit 70 mph then it falls flat on it face. Any suggestions I have replace plugs, wires, cap and rotor. Stock motor only mod is a cold air intake.

Is it shifting into overdrive when it falls flat? If you leave it in drive (not overdrive) so it stays in 3rd does it still fall flat?

 

[USCGunner]

It was in Od I will try it in D and see if it still does it. Thanks

 

[a91what]

If it does the kickdown cable may need adjusting. Jrichker has a write up on this procedure I believe

 

[jrichker]

If it does the kickdown cable may need adjusting. Jrichker has a write up on this procedure I believe

That's one thing that I don't have... I have successfully avoided AOD and AODE of all flavors...

 

[General karthief]

Are we talking looses power or just will not go any faster? What are you rpms at 70mph?

 

[Mustang5L5]

Stock 2.73's (or optional 3.27's) That thing should pull pretty well up to 130MPH or so.

OD won't engage at WOT. So once you finish with 3rd gear, you can only proceed to 4th(OD) if you let off the gas and proceed at partial throttle.