First Post! Vacuum Issues

[Tophipe]

Hey guys, I'm new to the forums. I have a 1983 CA CJ7 with a howell tbi and I recently started having issues with idling and stalling. The jeep would rev itself up when idling and it would stall unless I feathered it. I assumed there was a vacuum issue. When I was under the hood today, I found a vacuum line and I can't for the life of me find where it goes to. In the attached images it is the hose that extends from right side of that cylindrical thing behind the brake booster (kind of looks like a charcoal canister but its not). The hose on the left goes to directly to the exhaust manifold. I haven't had any luck in identifying the canister or the hoses using my vacuum diagram. Any help is greatly appreciated. Thanks!

Edit: So i think the canister is the "vacuum storage resevoir".

 

[gert]

Welcome aboard I am also not sure what the vacuum canister is "powering" but i do see that it is tied into your intake manifold. I have found an easy way to find vacuum leaks and clean your engine is carb cleaner. when you spray it over something that is leaking ie intake gasket, throttle body gasket, vacuum hose anywhere it is leaking will suck the carb cleaner into the engine and will change the idle speed of the engine that will point you in the direction you need to go. as far as what are some common leak areas? the intake gasket, you throttle body adapter gaskets are 2 big ones to look at, after that look at all you r hoses and check for hardness and cracking

 

[Torxhead]

The canister looks like an oem unit that came with the ca smog setup. It should have been removed with the tbi conversion. If you don't have the Howell vacumn diagram the complete conversion instructions are downloadable from Howell Engine Development's website.Your stalling issues could be from a bad idle air control valve that was installed by Howell and seem to be prone to failure or a vacumn leak at the tbi base which is also common. The tbi system is quite sensitive to vac leaks.

 

[Tophipe]

Thanks guys. I'm almost certain that the idling problem is because of that disconnected line. I pulled the canister and I think what the PO did was relocate the vacuum reservoir which is normally under the fender if I'm not mistaken. I found a link saying that the vacuum reservoir is connected to the Hg vacuum switches but that it didn't say anything about it taking air from the intake. I plugged it and ran it and there is definitely a significant amount of air in running through it. I thought of the idler control valve too, but a disconnected vacuum line seemed like a better place to start. I also just did an engine overhaul so I'm pretty sure the intake gaskets are good (they have been for the last 3 months) and I have mostly silicon vacuum lines so I don't think any of them have cracked. I think the only problem with the carb cleaner trick is that my idle is out of whack anyways... or I could be wrong. I've never tried it before.

 

[gert]

If you suspect a loose vacuum line which you could very well be right your vacuum lines should look like the attached post since you have the TBI and the tin can in your pic should be removed Howell Vacuum Lines setup by PO - JeepForum.com

 

[Tophipe]

Update: Pulled off the tin can and plugged the hose from the intake manifold. No stalls or anything like that. Also ran error codes on the tbi and came up with nothing. I think all the can is used for is maybe cruise control (not that I've ever used it). Thanks again guys, you were all a huge help. If you're ever in the Reno/Tahoe area hit me up and I'll buy you a round

 

[thescot]

I have an 83 7 as well, like you mentioned my vac reservoir is on the passenger side fender down low. Its also completely out of the loop line wise. Look on Howells website and follow the PDF to the jeep kit for a vac line schematic and directions on the install. BTW, the one provided by Gert is correct but if your not a Ca FI set up there can be a few variances in the CTO valve and plumbing.

 

[Tophipe]

All the CTO lines seem to be routed correctly. Just taking all of those lines out seemed to fix the problem. It's running pretty near flawless right now. We'll see how long that lasts.