Topic: Vacuum issues

[jfrabat]

Guys, I have a question; my idle was a bit high, and I noticed that I was running out of vacuum pressure because the cruise control was loosing strength, so I started checking my vacuum system, and I noticed that if I pinched the CCV line, the idle fell back to normal levels.  This to me means that the metered hole of the fixed fitting has been messed with, and it is no longer limiting the airflow as it should.  So my questions are:

1. How can I restric the airflow back to the normal level?
2. What happens if I eliminate the cranckshaft ventilation?

Please help me, as I want to send the Jeep working properly to Panama in less than a month...

Felipe

[sharpxmen]

you will still need to give the extra air somehow as the flow with the throttle closed is thru the valve cover and then via the pcv (or ccv, not sure what the difference is) into the intake - it might idle too low if you don't (i think, but easy to verify). if you just block it all the blowby will end up in your filter, you only want that to happen when there is enough airflow so it will suck those gasses and oil vapors in (so that is when the throttle is open). not sure how you can restrict the airflow back to normal, you could squeeze the tip of the nipple to give it less flow, or find a way to block some of it but not all - but i would say do this until you find a replacement. Also look and make sure there is nothing else unplugged as that would give you the same result or maybe the plastic tube might be broken somewhere and is drawing in air - i think even the brake drum itself or the hose can have the same effect if there is a tear in either one of them or if it is not seated properly, but you would notice that pretty quick.

[jfrabat]

I think I should give a little background here; about 6 months ago I replaced all my vacuum lines and the rubber elbow connectors, as they were old and some were showing cracks.  For the brake booster,  installed a vacuum reservoir, and I know there are no leaks beween the resevoir and the booster because if I disconnect the hose the morning after using the car, yo ucan hear the air flowing in because there is still vacuum there.  I also run my cruise control with the vacuum, but I added 2 reservoirs in the line to avoid running out of throttle power (if there is no vacum, there is no power to pull the throttle cable) when going uphill (which, when on 5th, ussually ends up in WOT, so vacuum drops significantly).  I also added one more reservoir for the HVAC system, as, at the begining, when I bought the Jeep, when the Jeep was going uphill, I could feel ir coming out of the defrost vanes, which was becasue the HVAC was runing out of vacuum and the reservoir corrected this.

The Jeep also has always idled a bit high for my taste, but since it was below 1K, I never paid much attention to it.  But now I find that by just pinching the line, the idle drops to about 700 RPM, which is where it should be in the first place.  So I will once again run over the whole system to make sure there are no other leaks (which I dont think there are, but just in case) and, in the mean time, find a way to restrict airflow from the CCV plug (at this time, I am using a ziptie to squeeze the vacuum tube next to the fitting, and, while not perfect, it helps).

Any good idea on how to heck the whole vacuum system?

Felipe

[neale_rs]

Does it matter where on the line you pinch?  This may help you find a leak along the line.

Other than that, maybe you can get a new metered hole fitting from a dealership or a used one in good shape.

[sharpxmen]

Any good idea on how to heck the whole vacuum system?

Felipe

unplug 1 hose at the time (not the ccv) and put your finger to block the fitting, when the idle is at 700/750 that's where your leak is. I don't think the ccv is the problem unless somebody drilled the fitting out to a larger diameter.