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Discussion Starter #1
I need help locating a missing vacuum line on an '86 2.8L TBI (Blazer 4x4). I have everything hooked up correctly according to my A.I.R. diagram, but there is an "ACC VAC SUPPLY" line with a check valve that sends lines to a few spots behind the engine bay. The check valve has two outlets, but one of the lines is missing, thus creating a leak. The other line has a T-junction on it, sending one line through grommet in the firewall towards the driver's dash and another line to the top of the tranny or perhaps the transfer case. If someone can tell me where all the vacuum lines should go behind the engine bay, I can try to figure out which is missing.

Thanks,
Brian
 

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On my 86 that line connected to a vacume reserve ball and the cruise control actuator both on the drivers side fender.
 

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Discussion Starter #3 (Edited)
Mine does not have cruise, but I'm starting to think that the one in the dash goes to the A/C control, and the other two would likely be the transfer case (4-wheel drive actuator) and the brake booster. Does that seem right?

It looks like I'm missing the brake booster line, but I'm not exactly sure where it goes.
 

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the brake booster line comes out of the intake its 5/8" hose so thats not it. only one of the vac lines should run to the transfer case switch and the switched line goin to your activator on the pass side wheelwell. do you have a huge ball type thing above your stearing box? thats the vac reserve and usually has a line running to it.
 

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Discussion Starter #5 (Edited)
Thanks! That was it!

I found the tube leading to the vacuum ball disconnected and the broken fitting from the end of the check valve still in it. Hopefully, I can find a replacement check valve and I'll replace this vacuum tube since it's pretty worn and loose on both ends. I also discovered that the purge hose was disconnected at the Canister.

Now could replacing these disconnected vacuum lines be the solution to get my engine to pass emissions inspection? It blew almost twice the legal limit of CO the other day. If this doesn't fix it, what should I try? I've already replaced the distributer cap/rotor, wires, and I'm in the process of changing the plugs. The MAP sensor was disconnected for a while and I had just reconnected it teh night before getting it inspected, so that may also do the trick. I'm just looking for other things to try if necessary.
 

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a vacume leak such as the one you have will make it run rich therfore failing the e test ... alsothe map sensonr being un pluged will really mess up thing in the emissions test one more thing you may want to do and this may sound stupid but change your oil right before you go for the test again it sounds crazy but i got mine tested and it was over they told me to try this and it worked. another thing would be the gas cap it self but im sure they tested it the first time you got it checked out.
 
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