I bought an '01 blazer and it needed repair first. It's all good to go now except for a few things here and there. One of them is there is a Vacuum Hose under the hood that was not hooked to anything and I can't find where it should plug in. For now it's capped off but there was a piece of tubing on it about maybe 4 inches long. Here is a photo of the piece. It's on the drivers side right by the firewall. Can anyone tell me what this is for and where it is suppose to connect to?

Second, the gas gauge jumps all over the place randomly. It will jump to full and then goes to empty and then back to half. It has about a half of tank in it right now so it will go back to where it should be but just wondering what would make it jump around like that?

 

Vacuum:
Do your heater functions work properly?
Pull your driver's side inner fender Toward door there's a ball vac reservoir

Fuel Sender.
Bad wiring either from dash to sender.. or sender to ground point over rear crossmember above differential.. Check wire harness coming from top rear of tank.. if there's a bulge, unwrap it. May be bad splice from FP connector change from bad crimp on those stupid butt connecotrs . The gray and black wires are for pump, Blue or ppl and black with white stripe for sender. But if one's bad, check all.


OR
FP connector is the troublesome 2x2 config
OR
Airtex FP assy.
- when sender 'worked' did it more or less measure in 1/8 increments or smoothly? If 1/8ths... it's an Airtex.

Future readers: Whatever the car, when you change the FP, keep the old one if you use Airtex. You'll probably be rebuilding it and putting it back in. I know I'll be doing that in my Tbird.
I chalk it up as taking one for the team.. Airtex's aint worth **** in Fords either.