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Won’t idle

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electrictech View Drop Down
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    Posted: May/07/2019 at 6:43pm
I have a 68 javelin with a 232 6 cylinder. I took the
The head off to take it to a machine shop to have a broken bolt removed. I put it back together and now it won’t idle. When I rev the engine I can hear a high pitch 
sound like a fan belt but I know it’s not. And it backfired sometimes out of the carb. My guess it’s sucking air into the intake manifold. I used a gasket that I purchased from the amc store that had both intake and exhaust openings. I have a intake gasket only left over. Should I had used the intake gasket along with the exhaust gasket also?
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purple72Gremlin View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: May/07/2019 at 6:51pm
sounds like a vacuum leak......and did you have the manifolds nachined?  Usually...they warp...and wont seal....vaccum leak.....
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 1970390amx Quote  Post ReplyReply Direct Link To This Post Posted: May/07/2019 at 7:03pm
 Without seeing the gaskets that come off I would say you needed to use both gaskets that were in the set. As was pointed out above you really need to check the gasket surface with a straight edge and make sure its flat. 
1970 390 4speed Bittersweet shadow mask AMX
1970 Amx missing most everything, or in a box
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Post Options Post Options   Thanks (1) Thanks(1)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/07/2019 at 9:23pm
what those guys say is it. the later replacement gaskets, Felpro, etc, were the two-piece set, that solves a lot of problems with the OEM gaskets. there is a recommended procedure (aka mandatory procedure!)  for installing them that's different from the stock set, because they are different thicknesses and stack differently.  the two manifolds are bolted together, and need to be loosened because their relative position shifts (by the thickness of one of the gaskets). this has it's own set of complications of course as the studs are heat-rusted in etc. (i own a can of Permatex nickel anti-seize due to the 232 manifold set).

i suggest taking both manifolds, taken apart, to a machine shop and have them slap 'em on the big belt sander. it's lousy for heads but perfect for manifolds.

this stuff is 50 years old, long gone are the days you can just slap new gaskets in. in my experience all of this stuff each takes a whole day's worth to bring it up to standard. i find this pleasant (when ou get to plan for it!). but i'm weird.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2019 at 7:21am
There is a tightening sequence for the manifolds. Scroll down to about the middle of this page:

As noted by TomJ, you will find that the four bolts that hold the manifolds together are the LAST ones to be tightened. You may not need to remove the manifolds at this point -- just loosen all the bolts, tighten in sequence, ans see what happens. If that fails you'll need to pull off and start over, maybe with a new gasket. The exhaust manifold is especially prone to warping, so having them surfaced at a machine shop before reinstalling is a good idea... doesn't hurt the intake either, as it can warp over time also.
Frank Swygert
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electrictech View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote electrictech Quote  Post ReplyReply Direct Link To This Post Posted: May/11/2019 at 2:05pm
Thanks everyone for the advice. I use the intake manifold gasket that came with kit and that solve the issue.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: May/12/2019 at 10:49pm
good! we've all probably done this job twice, like you did! and more than one time. it's a lot of surface area to get zero-leak, and with old metal. glad it worked out.

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