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So I just bought an 87 f150 with a 4.9. At some point someone pulled the smog tube and plugged the ports. But it idled low and mostly stalls if you come of the gas when it's stopped and in gear.
Not too experienced with the whole thermactic system, do the solenoid son this thing (vacuum distributor?) need to be plugged or reconnected or is this completely out of the picture since the air pump and smog tube are gone? Sorry if this has been asked before I couldn't find another thread on it. Thanks!
Last edited by CockroachJohnson; 02-26-2017 at 10:49 AM.
Theoretically the solenoids should remain plugged in and the vacuum lines plugged.
im gonna rerun the small lines to the solenoid when I get home. What about the house that used to go to the smog tube, can that cause a leak if it's not plugged?
If you have vacuum going to the electric solenoids, then the vacuum out lines would need to be plugged.
If the vacuum lines to and from the electric solenoids are both eliminated already you shouldn't need to replace them.
But the wires should be plugged in to the solenoids; you just don't want them to open with a vac line ready to create a leak when the solenoids open.
Follow that ?
Well I reconnected all the existing vacuum lines without much diffeeence. But I popped this little cap off the tree and with that open vacuum leak the problem is completely gone. So I'm thinking maybe timing or an o2 sensor?
02-26-2017, 10:46 AM
87 4.9 vacuum question
