Vacuum canister question

[jasongreg28]

I was tracking down a strange erattic tick on my renix that i supected to be vacuum leak. In the process i noticed with the engine off the vacuum canister does not have vacuum like my other jeeps is this normal or do i have a bigger problem.

[cruiser54]

Start tracing the hoses. Most common place is behind the battery that they split.

[ParadiseMJ]

A vacuum cannister will not make a ticking sound. A purge solenoid will. If you're driving a RENIX look elsewhere for "ticking". If you're driving a 91 or 92 (HO) look to the purge solenoid.

[HOrnbrod]

A vacuum cannister will not make a ticking sound. A purge solenoid will. If you're driving a RENIX look elsewhere for "ticking". If you're driving a 91 or 92 (HO) look to the purge solenoid.

 

No factory purge solenoid on the 91-92 MJs, unless it was a Cali dealer installed thing. Those started from the factory on the 93 ZJ 4.0L.

[jasongreg28]

I am new to these Renix motors. My other jeeps are 96xj 98xj. All i have to compare to and they are completly diffrent. The ticking is coming from around the manifold it comes and goes i can not pin point it. I can find no vacuum leaks yet. but my vacuum bottle not canister when i turn off the engine wait a minute there is no vacuum in the bottle. There must be a leak right?

[ParadiseMJ]

I'm a bit confused on the terminology here, I guess.

 

EVAP cannister is in the engine compartment aft of the oil filter. It has a vacuum source hose from the manifold and a purge/vent line from the fuel tank. There is no residual vacuum once the engine is turned off.

 

Vacuum reservoir (or bottle) is behind the front bumper on the passenger side. This should have some residual vacuum when engine is off.

 

Anyhoo, if you have a leak in the vac lines to the reservoir it should really only affect HVAC controls and MIGHT change the idle a bit (maybe). It should not change the way the Jeep runs.

The EVAP cannister just sucks gas fumes out of the fuel tank and into the intake to be reburned. I have had leaks in both that did not affect the running of the motor. If the EVAP cannister is leaking you'll fail smog (here in sunny CA anyway), just on the physical fuel tank pressure test.

[jasongreg28]

I havent got my tac working yet when it idles it seens to fluctuate about 200rpm back and forth. I was thinking vacuum is that normal i don't know renix motors yet.

[Jeep Driver]

Vacuum can/bottle/tank/football also effects those models equipped with cruise control IIRC........not that that applies here.

[ParadiseMJ]

No factory purge solenoid on the 91-92 MJs, unless it was a Cali dealer installed thing. Those started from the factory on the 93 ZJ 4.0L.

 

:dunno: I thought it was just HO's in general. I was trying to go a whole day without learning something, I guess this day is shot.

 

:dunce:

[HOrnbrod]

:dunno: I thought it was just HO's in general. I was trying to go a whole day without learning something, I guess this day is shot. :dunce:

 

Oh crap. I'm real sorry to ruin your day Paradise. It will never happen again. :cheers:

[jasongreg28]

Ok i finally got my tac working it is idling lil below 500 what would cause it to idle so low

[carnuck]

IAC needing adjustment?