I have a97ford f150 and when going down the road at about 30 mph the truck will start jerking like something is slipping or grabbing and holding it back or like if it was a standard tranny and you were trying to take off in 5th gear from a stop how it would jerk. It has 253,000 miles on it. What you think? It don't do it all the time just every so often.

 

Prolly just missing. Most likely a coil or plug

 

No I don't think it's that. I know what that is like its something else.

 

Detonation maybe? Buy a bottle of octane booster and keep it in the truck.

Next time the truck starts that jerking behavior, pull over and add the octane booster. If that solves the problem, you may have carbon buildup on the cylinder walls that is increasing the compression to the point where detonation occurs. If the octane booster cures it, switching to a higher octane gas could solve the problem.

 

You could also try smogging the engine with Sea Foam.

 

Ok I'll try that thanks.

 

Its nice to get a lil jerky once in a while, oh wait that s a different topic