First off I dont believe the gauge is accurate. Within a few seconds my car is well past 100*. But I believe it is linear.

160* Thermo, Brand new Rad, Flushed and new coolant at 50/50.

Issue, when driving without A/C the temp will read a little above 1/4. But with the A/C on it will gradually get to 1/2. When its at that point the engine drops RPM as soon as I let off gas and press brake, down to about 500 (maybe less), then quickly recovers. It gets real close to the point were I dont think its going to recover the next time I stop, so then I have to turn off the A/C. On a side note, (A/C off) when it would be really hot out or in city traffic and the temp gauge is 1/2 it would not surge.

I know it isnt hot until 230*, but gauge inaccuracies aside, this issue is obviously a temp and A/C relationship.

Any clues as to whats up?

 

Well in Florida, it's probably 95° during a "cold start" this time of year. Won't take long to get past 100°.

I'd say clean the IAC valve, but you've got a TBI instead. Base timing is set right? What is your volt gauge reading when the coolant gauge is in the middle?

 

Glad I fianlly god a response! Voltage doesnt increase or decrease. Ill have to get the timing checked. Ill try to clean the IAC prob tomorrow then.

 

IAC has been cleaned. Idles quite well, but not when the A/C is on (still surges). Car still gets hot in normal city driving (little traffic and lights)...

 

Hmmm, you got me. I had the same deal with the car not wanting to idle when the A/C was on. I had a week alternator (volts running in the 12's with the car idling) as well as an IAC valve that was full of crud. The IAC did wonders for me after cleaning it, but you said it's already been cleaned.

 

Cleaning the IAC helped out a lot. But it still does it. The voltage is also steady at 13~14 (acording to gauge). Somthing I dont like though, is that when I use the A/C in city driving it gets hot, not hot by some ppls standards, but it is enough to make the car run like crap and sometimes completely cut off (only done that a couple of times).