I have just replaced fuel injector cyl num1. after reassembling, the engine is now revving up and down....what have I done to cause this...it wasn't doing this before I replaced inj....

 

Sounds like a vacuum leak. Double check that you re-installed all the hoses/vacuum lines and none are punctured/damaged.

If no luck, I think you'll have to retrace your steps as maybe you didn't install the injector/o-rings correctly.

And did you install a new injector, or a used one?

 

Thinking along the lines of a vacuum leak, did you reuse the upper intake manifold gasket? And did you torque it down in the right sequence and proper torque specs per FSM?

 

have checked for unconnected vac lines, replaced intake gasket with new one, used new injector, torqued according to spec an sequence.....I did clean throttle body and removed TBS from while doing so...I suppose TBS being out of adjustment could make run like this? im trying to learn the adjustment procedure for this. am I on the right track????thanks for your interest an input...as u can tell im a neewbee mech..