high idle ,runs rough 1996 4.3 c1500

jeff1216 · 11-19-2009, 07:16 AM

changed head gaskets, put every thing back together start it up runs rough ,high idle, exhaust is louder than normal. cant adjust timing or idle,its a sfi vortec. any body got any ideas what it could be or what i should start tracking down first.

davbell22602 · 11-19-2009, 07:25 AM

Was it running rough, idling high, loud exhaust, etc. before you changed the head gaskets?

mudseeker · 11-19-2009, 07:32 AM

vacuum leak........

jeff1216 · 11-19-2009, 09:51 AM

no it was running prefectly.except for the overheating

eponator · 11-20-2009, 04:50 PM

I second the vacuum leak... Grab a can of carb spray and start shooting all your hoses / connections while the engine is running. If you hear it rev while your sprayin start lookin in that area for a cracked vacuume line...

davbell22602 · 11-20-2009, 06:20 PM

Grab a can of carb spray and start shooting all your hoses / connections while the engine is running. If you hear it rev while your sprayin start lookin in that area for a cracked vacuume line...
__________________

never heard of that trick. I guess you learn something new everyday.

11-19-2009, 07:16 AM	#1
jeff1216 Junior Member Join Date: Nov 2009 Posts: 2	high idle ,runs rough 1996 4.3 c1500 changed head gaskets, put every thing back together start it up runs rough ,high idle, exhaust is louder than normal. cant adjust timing or idle,its a sfi vortec. any body got any ideas what it could be or what i should start tracking down first.

11-20-2009, 04:50 PM	#5
eponator Senior Member Join Date: Nov 2008 Location: SO Cal Posts: 772	I second the vacuum leak... Grab a can of carb spray and start shooting all your hoses / connections while the engine is running. If you hear it rev while your sprayin start lookin in that area for a cracked vacuume line... __________________ '99 F350 5.4L crewcab Longbed

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11-19-2009, 07:25 AM	#2
davbell22602 Senior Member Join Date: Nov 2009 Location: winchester, va Posts: 3,645	Was it running rough, idling high, loud exhaust, etc. before you changed the head gaskets?

11-19-2009, 07:32 AM	#3
mudseeker Senior Moderator Join Date: Feb 2006 Location: michigan Posts: 7,155	vacuum leak........

11-19-2009, 09:51 AM	#4
jeff1216 Junior Member Join Date: Nov 2009 Posts: 2	no it was running prefectly.except for the overheating

11-20-2009, 06:20 PM	#6
davbell22602 Senior Member Join Date: Nov 2009 Location: winchester, va Posts: 3,645	Grab a can of carb spray and start shooting all your hoses / connections while the engine is running. If you hear it rev while your sprayin start lookin in that area for a cracked vacuume line... __________________ never heard of that trick. I guess you learn something new everyday.