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My truck does not have the Vehicle Emissions Control Information (VECI) label in the engine bay. I am trying to redo my vacuum lines but I run into a problem
when trying to run a vacuum hose from the top port of the rear-most solenoid (TAB) to the valve that’s right by the smog pump. These are instructions I found on another
forum and the only ones I could find anywhere. Anyway, I do not see any type of a place for a vacuum hose to connect near the smog pump. Am I missing something or
is this only the case on certain vehicle. I have no idea where the top port of the TAB is supposed to connect to. Does anyone have a diagram for a 1992 F-150 5.0?
With air conditioning.
Yes, that is the post I was using until I ran into :
"All that's left is to run a vacuum hose from the top port of the rear-most solenoid (TAB)
to the valve that’s right by the smog pump. This was the hardest part for me, but I have
fat fingers, and truthfully it wasn't that bad; just annoying. Here's a pic, it might be easier
to plug the hose in from under the truck, but I was able to do it from the top"
I can not find anywhere near my smog pump to attach a vacuum hose, nor is there one there already.
Yes, that is the post I was using until I ran into :
"All that's left is to run a vacuum hose from the top port of the rear-most solenoid (TAB)
to the valve that’s right by the smog pump. This was the hardest part for me, but I have
fat fingers, and truthfully it wasn't that bad; just annoying. Here's a pic, it might be easier
to plug the hose in from under the truck, but I was able to do it from the top"
I can not find anywhere near my smog pump to attach a vacuum hose, nor is there one there already.
Hmmmm - yeah I see what you mean - on my truck the two valves controlled by the TAD and TAB were both on the back of the engine behind the intake - more like where the check valve and diverter valves are on his picture.
I don't have any of the smog pump plumbing any more so I cannot look at my truck - but you are not crazy - look around more behind the intake near the firewall.
Here ya go - I found the plumbing in my parts box - one of them still has the vacuum hose on it and the other does not - they are right next to each other.
It's not years - it's engine calibrations. Some have the combination valve in BLDTruth's pic; others have separate TAB & TAD air valves. This & the NEXT few explain that system:
Thanks Steve, I don't have a combined bypass and diverter valve unless it is behind the motor and I can't see it.
Coming off the air pump, I only have the filter and some other thing that doesn't have any vacuum lines running to it.
I have attached a photo. Ever seen one like that before?
It's just a resonator chamber, designed to reduce the drumming noise from the pump. They're very rare on these trucks in this application. I guess it was only a problem on a few calibrations.
01-21-2019, 06:18 PM
need vacuum diagram
