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ccv questions

bcmaxx

NAXJA Forum User
I have a 89 xj 4.0. Here is how my ccv is setup:

cold air intake with the ccv line tapped into the tube and going directly to the valve cover in the front. A small vacuum line from the manifold to the rear. My question is am I defeating the system by applying vacuum to both? should I just have a filtered breather on the front line? I am having some other running issues like lack and loss of power under load, especially when climbing long steep grades. Is this affecting the map sensor?
 
??

I don't understand where you are applying vacuum to both. You have filtered air entering the front of the valve cover--doesn't matter if it is from the stock air box or off the tube from a cold air intake. The rear has a metered orifice in the VC, the vacuum line to the manifold, and the manifold port--these all constitute the main problem areas. The orifice in the VC becomes clogged, the vacuum line becomes clogged, or the port on the manifold becomes plugged.

The only problem I have found with the filtered air intake end of things is the "J" hose degrades over the years and CAN collapse--literally sucked flat. You can pick up a generic "J" shaped hose at Autozone, cut to length and if it doesn't fit real tight on use a couple small clamps.

I don't believe it is causing your lack of power.

Fuel delivery or spark issues is what I would be looking at--when was the last time the fuel filter was changed? Last tune up--plugs, cap and rotor (brass, never aluminum contacts), wires?
 
Okay thanks, It seems t is fine then, all tune-up is recent, as well as ALL sensors. My cap has aluminum contacts, rotor is brass, I got it from the dealership? should I be looking for another brand? what s the difference?
 
Okay thanks, It seems t is fine then, all tune-up is recent, as well as ALL sensors. My cap has aluminum contacts, rotor is brass, I got it from the dealership? should I be looking for another brand? what s the difference?

The aluminum will burn up much quicker, degrading spark to the plugs.
 
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