Anyone upgraded their Vacuum canister?

My 97 XJ is having vacuum issues. Everything is fine at idle or low RPMs but the second my foot gets into it under load, vacuum seems to drop out and my HVAC defaults to defrost. Since I am on 33s with 3.55 gears, the Jeep is basically under load all the time. This is annoying because I get hot air in my face all the time when I would rather have it at my feet like I have it set. I inquired about this issue over in the OEM section and someone suggested the internal check valve in the canister may have gone bad. I could just buy an inline and call it a day but I googled Jeep Vacuum Canister to see what they go for and saw Summit Racing sells one for people who upgrade the cam and need more vacuum. I am one to always look at upgrading when I have something I need to replace. I plan to build my old motor as a stroker and subsequently upgrade the cam as well so would this be something worth it?

This is the one I am looking at.
https://www.summitracing.com/parts/sum-g1464?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-summit-racing&gclid=CJ3_rYmlzNICFdgOgQodc80BIg

More likely is a vacuum leak.

Agreed. I believe there are multiple check valves,not just at the reservoir as well.

A can of carb cleaner goes a long way in tracking down vacuum leaks.

old_man said:

A can of carb cleaner goes a long way in tracking down vacuum leaks.

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I have checked as many locations as I can with the exception of under the battery tray.

Under the battery tray is where it normally fails due to the acid and fumes.

old_man said:

Under the battery tray is where it normally fails due to the acid and fumes.

Click to expand...

Which is what I have heard. I do plan to remove it and check, I was just getting an idea of what it would take to replace the canister and then found the one from summit racing.

Also look at any of the hoses that come off the intake.The short hose from the intake to the first vacuum "check valve" was split on close investigation.Had the same problems as you.

You can relocate the canister to passenger side firewall area and reroute the vacuum lines. Mine is ziptied in that area and has been happy there since 2007, with zero issues.

If you find that the canister is bad and not just leaky lines, the stock ones area cheap and much easier to relocated than the big canister that you linked.
https://www.summitracing.com/parts/...se1-_-dorman&gclid=CLOopoKJ1NICFdQ6gQodN6cBDw


I've not heard of insufficient vacuum with a streetable 4.0l based stroker. With a race cam, maybe.......

Bad check valve.