1986 Chevy G10 Van Vacuum Hose Diagram

1986ChevyG10 · February 12, 2016

Hi everyone,

I have a 1986 Chevy G10 Van with a 4.3L 262 Vortec Engine. It is fitted with a Rochester Quadrajet carburetor and I am having some problems figuruing out the routing diagram.

I'm going through the diagram line by line and I am looking at the line coming from the distributor that goes to the Vacuum regulating valve. It branches off there and leads to a few things1)spark retard delay vlv, efe/distr tvs. I really can't see in here because it's so tight.

How is it best to tackle this? Eliminate all the unnecessary vacuum lines or do it the way the diagram shows? I'm open to either.

Q: Does it make sense to plug some lines so the van runs better? It doesn't have to pass emissions anymore

Before anyone asks, I'm doing this only because I knocked a few lines off when doing a water pump repair and it's idling too high now.

Link to the vacuum hose diagram from under the hood:

Ann Arader · July 9, 2019

I searched on this - but found no answers. I'm the original (proud) owner of a 1986 Chevy Van with the Vortec 6 cyl engine as well. It was running badly when out of town - so had to take it to a shop on the beach... They told me it needed a new carburetor... MONTHS LATER I get my van - only to find it runs like a rocket trying to take off - even when not touching the gas pedal... and SURPRISE - they have decided to remove the entire vacuum system!!! --- The original carb was disposed of... and I've YET to get my poor beloved van running properly again. --- HELP???
Was it even ADVISABLE to "BYPASS" or REMOVE the entire vac system??? --- Apparently it is difficult to find a carburetor that will even work with the old system. I just want to get my sweet chevy van running again - it was running FINE before the old carb failed and started causing all sorts of trouble (carbon in the intake manifold etc)... Did you ever find a solution for your 1986 G10 Vortec V6? (auto trans) ---- ??? PLEASE HELP!

riverbanks · July 9, 2019

So in park it's idling high as well?I would take needle nose pliers, squeeze every vacuum line,one by one till problem disappears,one is either hooked in wrong place or a defective valve