You have an internal leak (carb) if gas is getting in the vacuum.

 

ahh. how would i track down which circuit is leaking? oh and had a friend come over to try his hands at my truck. he took a video of it idling... well...guess you could call it idling. any way he has the ignition advanced as far as it'll go which is where it started up and would run and the idle set screw turned in all the way and the choke came open. but when it was closed it was closed all the way.. no gap what so ever. would touch the throttle and it would die.

 

Didn't you just answer your own question? Maybe HAC means "high altitude compensator" valve.

I hope that's it, but I don't know how to fix it.

 

ok so there was deffinatly a bad gasket in the carb, still have some spray when you open the throttle but not as much and the O2 sensor was fried. starts easier but the ignition timing is advanced all the way, back it off and it won't run. the timing for the distributor and cam is set and no signs of any skipping teeth either on the belt or gear.

 

ok, so hooked a timing light up to it this morning and looks like its running about 5 degrees or so ATDC. is this bad? little bit affraid to take it out of my driveway.

 

nikie: if there is still something wrong with that carb, then fix that carb.

You may want to enlist some local help. Look for some guys with gray beards and classic cars.

 

the carbs fixed, no longer leaking or spewing gas. i took the ignition module in to get tested and passed on 3 tests. i pulled and checked the distributor drive gears and no abnormal wear on the teeth, cleaned it up and visualy checked the pick up coil and trigger wheel and the tiny wires and all seems fine. i'll be putting it back together tomorrow and see what it does. had somewhat similar issues on my 84 GMC jimmy s15 and took the carb apart and rebuilt it, still wouldn't run right, checked the ignition module and passed, distributor was fine and when i put the distributor back in it ran like a champ till i smaked a center divide at 65mph due to a failed lower left ball joint.

 

What a story! I hope you got out unharmed other than a racing pulse!

 

i did but the truck was totaled. the mazda is what replaced it. ok, so now heres the question. the book says to line up the dimple on the gear with the mark on the distributor, well the chiltons manual i'm useing, the picture is not very clear and seems it... like several key pix in the book where printed badly. now there are 3 marks, a long recess, short recess and a raised ridge, set at different spots. which of these 3 do i use because when i pulled the distributor out, the bottom was coated in oil and sludge.

 

I am surprised it will start. Retard the spark to 5 btdc.