slimbobaggins

Engine is bogging on full throttle, pulled a vacuum on my advance diaphgrams and they're fine, went to check the lines and I think they're routed wrong.

Outer line (further from engine) is routed through hard steel line to the carb (carb port is circled) and holds vacuum just fine.

Inner line (closer to engine) is routed through hard steel line to some sort of switch on the fender well? (circled in red) I assume that this should run to a port on the manifold? Also, line doesn't hold vacuum anyways, when pumped from the fender switch side. Don't know if the line is T'ed somewhere, or if it's rusted through where I can't see it.

I have the Haynes manual, but the vacuum diagram isn't the greatest resolution to trace out the lines.

Suggestions?

slow-mo

Both vacuum lines go to separate ported source on the carburetor above the throttle valve. That would be your 2nd picture.

The one closest to the vacuum advance does connect to a T-fitting to that vacuum switch on the fender.

The factory service manual (FSM) does show a detailed vacuum hose routing in the emissions section (EC-25), page 157 in the PDF page box. The FSM is somewhere here on this web board. I downloaded it awhile back.

slimbobaggins

I found a copy of the '85 manual... the federal diagram looks pretty close to my '87.

Problem is that it looks like that line runs directly to the vacuum switch, with no other T visible, or other vacuum lines that seem to go to "nowhere" that might meet up with a T that is out of view. If there is a T somewhere that I didn't see, then it would make sense why it's not holding a vacuum, but I just don't see where it would go to.

slow-mo

The lower half of that same picture you just posted, shows the routing of the vacuum hose for the vacuum line closest to the distributor. In the hose routing pic, it looks like it goes to the second port down from the top of the four vacuum hose ports.

Going back to your 2nd pic you posted, it looks like it should go to the left of the hose you circled in red. Since I don't have my '87 anymore I can't physically check and let you know.

slimbobaggins

I guess I was looking at the graphic wrong, I thought it showed it coming off and going directly to the switch.

Im going to pull those steel lines and vacuum test them, so I'll get it straight.