90 YJ 4.2 Exhaust - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > YJ Jeep Wrangler Forum > YJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-03-2013, 06:13 PM   #1
Jeeper
 
Join Date: Apr 2013
Location: Phoenix, AZ
Posts: 118
90 YJ 4.2 Exhaust

I have a few problems with my exhaust that I would like some advice on.

First it seems like the flange on the downpipe is not sitting properly. I have a brand new cast iron exhaust manifold and the bolts will not stay in. I have to tighten them every other day and it's getting really annoying. I replaced the bolts but no go :/


Also the engine has a weber (i think it's a 38 dges) carb and has been nuttered. The 2 exhaust loops that feed back into the carter air cleaner are both just sitting open in the engine compartment. Is it safe to cap and weld those 2 pipes? One goes to the downpipe and the other goes to the cat. This is a street driver for me too so I need it to pass Phoenix, AZ emissions.

__________________
1990 YJ 4.2L
Currently in the shop for an 8.8 swap!
Meshugga is offline   Quote
Old 07-03-2013, 06:25 PM   #2
Jeeper
 
Mbclark's Avatar
 
Join Date: Jun 2013
Location: Rancho Cordova
Posts: 332
Manifold - should have studs in the manifold and nuts to secure the down pipe. I used red locktite and they haven't worked loose at all.

Pulse Air pipes - can be pinched and welded if the excess vacuum was removed when the nutter was done. Assuming of course the vacuum isn't required for emissions regulations in your state. Not sure what AZ law is regarding that.

Mbclark is offline   Quote
Old 07-03-2013, 06:27 PM   #3
Jeeper
 
Join Date: Apr 2013
Location: Phoenix, AZ
Posts: 118
I don't think they care about vacuum as long as the levels in the exhaust are good.
__________________
1990 YJ 4.2L
Currently in the shop for an 8.8 swap!
Meshugga is offline   Quote
Old 07-04-2013, 01:03 AM   #4
Jeeper
 
Join Date: Apr 2013
Location: Phoenix, AZ
Posts: 118
I found that the bolts were too long because I was not using the belleville washers because they are now MIA. After closer inspection the flange was not 100% in contact with the manifold. Thanks Mbclark. I will find suitable replacement washers and use locktite red.

I am going to follow the lines up and see where the vacuum goes off to. Almost all of the vacuum lines are disconnected.
__________________
1990 YJ 4.2L
Currently in the shop for an 8.8 swap!
Meshugga is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Download our Mobile App

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 08:04 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC