my rad fan only comes on when the ac is on, regardless of what the coolant temperature is. is this a normal thing for these cars?(mine is a 91 TBI 305 Formula)

i have another thread on this forum called 305 TBI skip, i tried to rename it 305 TBI skip HELP me please but i don't think it worked. that deals with a more urgent problem with my car and i'd appreciate any advice on that one. here it is again:
i recently changed the head gaskets on my 91 305 tbi powered formula. ever since the head job i have had a skip. it is most noticable at lower rpms just off idle while cruising but is still there throughout the entire rpm band. it causes the car to lurch and shake. also my idle is eractic when, jumping from 500 to 900 rpms. she also goes through more than double the fuel she did before i changed the gaskets. i have checked and rechecked the valve lash, cannot find a vacuum leak and can't find anybody with any idea what is wrong. i also removed the smog pipes during the head job but don't see how that would cause a skip. anybody with any ideas please help me out here. by the way it is the stock hydraulic roller cam and i set the valve lash at 1/4 turn past zero lash. it seems to work better than any other spec i read. let me know if you have questions or answers.

 

Fan problem is due to a dead fan switch (in the pass. side head).

As for the engine issues, how did you adjust the lash? The method that works the best with the engine off is to adjust the exhaust lash as the intake valve just closes and adjust the intake lash as the exhaust valve just opens (I think its in that order). This ensures that the lifter being adjusted is on the cams base circle. Do this for all the valves, make sure to take note on which have been adjusted so you dont mix anything up, and dont use the balancer bolt to turn over the motor. There are adaptors that bolt into the balancer that allow you to safely turn the motor over. Other then that, it may be a faulty head gasket (blown out between two cylinders), ignition issue, etc.

 

i set the lash with it running, backed off the rocker until it rattled and then tightened it until the noise stoped then 1/4 turn. i tried various techniques for engine off adjustment, i've never heard of the one you mentioned. for that do you adjust the rockers for one cylinder then go to the next? in all the other techs you do opposing cylinders(#1 at tdc, adjust #8). i don't think it's faulty gaskets since they were brand new and seemed fine and i can't find any prblem with the ignition either but that doesn't rule it out entirely.

 

The method I describe requires that you adjust one cylinder at a time. If you do this, make sure that you, for lack of a better word, jiggle your push rod up and down to feel for zero lash rather then spin it. This makes zero lash easier to feel.

Also, have you double checked the firing order? Stupid thing, but every once in a while its easy to mix up a wire or two.