Vacuum line diagram for 5.7 liter carburated 1986 GMC K2500

V-8 engine firing order is: 1-8-4-3-6-5-7-2

4.3 liter V-6 firiing order is: 1-6-5-4-3-2

in usa, open hood and look up
its the law here.
if , hood lost?
then alldata dot com,

No. The vacuum used to purge the vapor system is supplied by the engine. If the valve was clogged the vacuum would never reach the system in the first place. However as fuel is pumped out of the tank, air needs to be able to enter to prevent a vacuum lock condition and the fuel cap is resposible for allowing air to enter.

The diaphram can tear, but when this happens it typically leaks gas into the crankcase. Is there gas in your oil? If no, recommend you take the float bowl cover off and see what's going on when you start it. Please let me know if you have more questions.

For this models:
1986 GMC S15/T15 4WD P/U 2.8 liter V-6 VIN "R"
1986 GMC S15/T15 4WD Jimmy 2.8 liter V-6 VIN "R"
1986 GMC S15/T15 2WD P/U 2.8 liter V-6 VIN "R"
1986 GMC S15/T15 2WD Jimmy 2.8 liter V-6 VIN "R"



Hope helped woth this. Remember rated this help. Good luck.

I have the wiring diagrams if you need it. Send me your email and I will send you the wiring diagrams. It is a K2500 right? [email protected]

Get the Haynes S-10 repair book at the parts store for about $20. It has diagrams for vacuum lines.

These are a vacuum line nightmare. I take it the diagram isn't still on the bottom of the hood?

can you see the diagram under the hood? if not try searching a junkyard for either the diagram or a complete motor

Carb vacuume lines? I can direct you to a holley website .... it has a diagram that has the q-jet vacuume routing all you have to do is look at the diagram then scroll down and look at the number to see where it goes.

http://www.holley.com/data/Products/Technical/199R9881.pdf

Hope this helps.