hey got a question in the past 2 days i bypassed my coolant from the throttle body on my 87 305 tpi and advanced my timing to 12 degrees. now my fans witch normally kick on around 235 or so dont kick on till 250 just before overheating is this late fan reaction caused by the advanced timing or throttle body bypass

 

Your fans should kick on at the same temp regardless of the two items you changed, the fan switch has no idea what timing you set it at. It is just coincidence this is now happening. The car will run a little hotter in most cases with higher timing, however the fan kick on temp is the same regardless, if you have dual fans it sounds like you may have a bad relaying kicking on the secondary fan only, this fan comes on under two conditions, it meets the specified temp by the ecm, or when the A/C is on. So it sounds like the primary is not kicking on, only secondary.If you have a dual fan set up, run car with A/C on max, and be sure both fans turn on, if not you may have bad relay or ECM