When going down the road. Under a stedy Pedal. The engien will some times Hesitate. Or jolt. in a DeAceleration kind of way. Only once, and only for a secound. I am thinkin detanation. But i've never whitnissed detanation. so i can't tell for sure. It did it twice last night. And the smoke color changes with the mood of the car. White and black.

 

white = burning coolant

black = too rich

Have you messed w/ the AFM? Do you have new plugs, wires, cap?

 

new plugs(only about 1100K miles on them) New wires. New cap and button. I have not mess with the AFM. I might look into a new head gasket for it. I want to see what the pistons and walls look like.

 

bad connection inside your TPS?

 

CHTS (Cylinder Head Temperature Sensor) could have a bad connection or could be bad. They're very temperamental

 

My car did that when I did my TB swap. I had not drilled the 240sx TPS holder and it was friction held by two pieces of fuel hose. Small movements of the TPS would cause momentary decel or 'hesitation'.

Like Bleach says, check your TPS connection and see that it is mounted firmly and the clip does not wiggle excessively.

 

good place to start. I have a custom braket holding the stock TPS to the 240SX T/B. I'll check it out. thanks

 

fub, you have one at your disposal, just gotta learn to use a vom! Do the component checks! I will show you how to do the checks when you come back up, still gotta finish up the suspension and brakes.
kenny.

 

my tps is fine. It's probly just jumping around on it's mount like Tox said

 

Mine will do that around 3500 RPM under steady gas. If I accelerate, it goes away. Same thing if I get off the gas. I've never found the issue.

 

a hesitation can be caused by sooo manythings is hard to find, but definatly not the head gasket. mostly caused by ignition related things, tps, wires plugs, coil type stuff. or even your o2 sensor.

 

When my O2 sensor had crapped out, it was causing me hesitation in lower RPMs, but once I got to Higher RPMs I had no problem. Once I fixed my O2 sensor my issues pretty much dissapeared.

 

only one problem. Tach don't work. I have replace the resistor thing. checked over all wires. still nothing. I am gona try another cluster gauge. when ever i get around to doing it. Untill then. i will not know the RPM that it happneds at.

 

Well I think you'd be able to kind of guess, I mean is it right when you start up from a stop, at lower speeds, or right after a shift?