Quote:
Originally Posted by 428 78T/A
THen I heard someone on here say that a gas tank can and will crush like a pop can if the vacuum gets too severe.
So as a little experiment, I took off the plug at the gas tank and just ran a straight peice of rubber hose angled up at the gas tank. Sure enough, no more vacuum noise when I take the cap off, which I expected.
Well today after running the car a while I stopped at the post office and when I came back outside the car wasnt running, it stalled. It wouldnt restart for nothin. I walked home came back about an hour later and started right up.
It doesnt stall when the vapor line is capped. It only stalls out when theres no vapor in the tank but Im afraid Ill crush the tank if I cap it. What gives? Do you think the post office had sumptin to do with all of this  |
That basically says that you have a vacuum leak from the engine/canister
that is letting too much air into the intake for a proper engine restart.
(Much too lean). With no vent you had a over rich condition.
That being said, as you are not a "Engine Calibrator" I would hook the lines
up to the EVAP system as the shop manual shows for that model year.
So everything is working.
So at one time Pontiac had fuel tanks with a multiple line "collector" that
allowed tank venting and tank air replacement with a sealed gas car. All
of this is described in a proper year Pontiac Shop manual.
I was the one who posted that given the right amount of vacuum on the fuel tank the fuel tank can be sucked down to the size of a shoe box with no venting either thru a early style tank vent or a later style Carbon Canister system type venting.
Tom V.