idle issues again
 

i have an 87 na. 79000 miles

it was such a nice day out today i decided to go out and start my car up thats been sitting for a few months. the good news is that it started right up for me. the bad news is that it will idle fine for a few minutes at 850 rpm but will crash down to 200-400 and jerk around like it wants to stall. oil pressure is right below 5

its been sitting for probably 4 months or so in a garage covered. and right before i put it into storage i had a bunch of work done to it. I just had the timing belt done ( less then 1000 miles on the new belt. Hasnt been back for retension yet) and i also had almost all of the vacuum lines replaced so im hesitant to say thats the problem.

theres a half a tank of gas in it. could it be bad gas from sitting?

any ideas? thanks for any suggestions

Could be the fuel. Nearly all fuel is an ethanol blend in the U.S. and ethanol absorbs water. It will also cause gumming in a much shorter time frame. Run some BGK or SeaFoam (I prefer SeaFoam) into the tank and drive for a bit.

I'd look there before I deduced another problem.

^ +1