lately my motor starts shaking at 40mph then quits at bout 55. then it also shakes when I go up steep hills. put new fp and new filter on it. new iac and tps. new e-3 plugs and wires. cant find a vacuum leak anywhere. where else to look?

 

Did the problem start before or after installing new parts?

 

before. that's why I put all the new parts on it. got me scratching my head.

 

Driveshaft U-Joints, Only on acceleration??

 

Unless there is a definite misfire, I agree with Bob, u joints or something is out of balance.

 

its the motor that's losing power and shaking .

 

Does it miss when the engine is under load only? Does it free rev ok? Did you check underneath the dist cap? I'd look at fuel pressure at all speeds for grins too. And do some searching on the forums. I'm sure someone has had this problem and gotten good insight.

 

.its always done it going uphill. the motor at 40 just started.