Tex06 Posted July 16, 2017 Share Posted July 16, 2017 Ok, first off I'm actually scared to start my truck. Just did the manifold swap. 99+ intake, new exhaust. New power steering pump, all that jazz. Go to start and.... the engine takes off like a jet. Immediately revs to 4k before I shut it off. Did this 2 or 3 times. Disconnected the MAP and still does the same thing, although harder to start. Any guesses? Kinda need to get to work in the AM. Sent from my SM-G930T using Tapatalk Link to comment Share on other sites More sharing options...
HOrnbrod Posted July 17, 2017 Share Posted July 17, 2017 Sounds like your new intake is sucking air. Try capping off all the vacuum ports. Throttle body butterfly closing? Link to comment Share on other sites More sharing options...
Tex06 Posted July 17, 2017 Author Share Posted July 17, 2017 Sounds like your new intake is sucking air. Throttle body butterfly closing? That's what I was afraid of. TB looks fine, reused my old one. Had troubles getting the intake to seat properly due to header wrap.... I'm willing to bet that's the issue. Dammit. Sent from my SM-G930T using Tapatalk Link to comment Share on other sites More sharing options...
Green Mesa XJ Posted July 17, 2017 Share Posted July 17, 2017 Lose bolt and/or brake booster hose. Air is bypassing the throttle somehow. To test Spray some carb cleaner (or equivalent spray ) around the intake where it bolts to see if it changes. Oh one weird thing on a 5.0 mustang my buddy had a freeze plug like deal on the intake fall out. Never noticed anything like that on a jeep Sent from my iPhone using Tapatalk Pro Link to comment Share on other sites More sharing options...
Minuit Posted July 17, 2017 Share Posted July 17, 2017 Yeah, to me that sounds like air getting in where it shouldn't be. Link to comment Share on other sites More sharing options...
Tex06 Posted July 17, 2017 Author Share Posted July 17, 2017 Lose bolt and/or brake booster hose. Air is bypassing the throttle somehow. To test Spray some carb cleaner (or equivalent spray ) around the intake where it bolts to see if it changes. Oh one weird thing on a 5.0 mustang my buddy had a freeze plug like deal on the intake fall out. Never noticed anything like that on a jeep Sent from my iPhone using Tapatalk Pro Yeah I'm not comfortable running it long enough to do that. That would be my normal routine is bust out the propane and look for vacuum leaks but it's revving waaaayyy too high for my liking. Pulling it all apart today and gonna reseat the intake (without header wrap this time......sigh). Link to comment Share on other sites More sharing options...
cruiser54 Posted July 17, 2017 Share Posted July 17, 2017 Intake is hanging on the dowels. take it off and file it to fit with the exhaust manifold. Link to comment Share on other sites More sharing options...
HOrnbrod Posted July 17, 2017 Share Posted July 17, 2017 ^^ This. When I did my 99 intake install I chamfered the two dowel holes a little bit with a large drill so the dowels can slide in easier. Worked well. Link to comment Share on other sites More sharing options...
Tex06 Posted July 17, 2017 Author Share Posted July 17, 2017 Intake is hanging on the dowels. take it off and file it to fit with the exhaust manifold. ^^ This. When I did my 99 intake install I chamfered the two dowel holes a little bit with a large drill so the dowels can slide in easier. Worked well. I'll grab my die grinder and a few carbide bits from work. Should make short work of that. Thanks for the tip! Link to comment Share on other sites More sharing options...
HOrnbrod Posted July 17, 2017 Share Posted July 17, 2017 Intake is hanging on the dowels. take it off and file it to fit with the exhaust manifold. ^^ This. When I did my 99 intake install I chamfered the two dowel holes a little bit with a large drill so the dowels can slide in easier. Worked well. I'll grab my die grinder and a few carbide bits from work. Should make short work of that. Thanks for the tip! A 1/2" countersink bit would do the job too. Link to comment Share on other sites More sharing options...
MuddFoot Posted July 19, 2017 Share Posted July 19, 2017 I used a multi bit. If you used the apn header you need shims on your intake I used washers cut in half worked like a champ Sent from my Z981 using Tapatalk Link to comment Share on other sites More sharing options...
Tex06 Posted July 19, 2017 Author Share Posted July 19, 2017 I used a multi bit. If you used the apn header you need shims on your intake I used washers cut in half worked like a champ Sent from my Z981 using Tapatalk Used a 1/4" carbide burr and a drill. Tightened the pi$$ outta it, and it's much better now. Still a vacuum leak (idle hunts 900-1100 rpm) but something I can work with. I'm not sure who made my header, it's a solid stainless model I picked up a couple years back from Summit at their scratch and dent sale for $30. Had been installed once so they couldn't sell it as new, lol. I did notice though the header was slightly thicker than the intake....once I get my propane out and troubleshoot this, if it is where the intake meets gasket I'll try shimming and see if that helps. Thanks! Link to comment Share on other sites More sharing options...
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