strange miss at 1500 rpm

cburcham73 · 06-23-2009, 05:24 AM

93 bronco,5.0,e4od. ive been tracing this miss for 6 months.the trucks seems to hesitate,stumble at 1500-1800 rpm.only at that rpm.doesnt matter the speed,or gear im in. i had a burnt #8 valve,replaced with new heads and still have the miss. new cap,plugs, wires,checked all the sensors,tps,map,iac,iat. runs smooth before 1500,then slight stumble and after 1800 perfect,new fpr,good pressure. im stumped.

merlin5577 · 06-23-2009, 11:42 AM

Does the truck have an EGR valve? If so pull it off and check it for carbon build up. Sticking EGR valves can cause the problem your describing.

cburcham73 · 06-24-2009, 09:28 PM

i'll yank it off tomorrow. i know when i take off slowly and then let off the gas real quick it will stall.

tjzz4 · 06-25-2009, 12:11 AM

I agree.... You might take it off and put a piece of duct tape over the intake port and take it for a short spin.

cburcham73 · 06-28-2009, 04:33 PM

tested the egr,and blocked it off. to dice..could it be smog pump related. i heard of those things making the truck do weird stuff.

06-23-2009, 05:24 AM	#1
cburcham73 Senior Member Join Date: Aug 2008 Location: williamsburg virginia Posts: 182	strange miss at 1500 rpm 93 bronco,5.0,e4od. ive been tracing this miss for 6 months.the trucks seems to hesitate,stumble at 1500-1800 rpm.only at that rpm.doesnt matter the speed,or gear im in. i had a burnt #8 valve,replaced with new heads and still have the miss. new cap,plugs, wires,checked all the sensors,tps,map,iac,iat. runs smooth before 1500,then slight stumble and after 1800 perfect,new fpr,good pressure. im stumped.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
sporadic miss	rpp	GMC Truck Forum	4	04-20-2009 02:04 PM
Skip, miss, cut-out	Flowtech1ton	GMC Truck Forum	6	10-16-2008 07:37 AM
2001 miss	dthompson	Chevy Truck Forum	3	02-20-2007 09:53 PM
Miss or hesitation?	spacoli	Toyota Truck Forum	4	01-07-2007 12:10 AM
2000 silverado 1500 5.3 "miss" at idle	WDDOBLER	Chevy Truck Forum	7	02-02-2006 06:44 PM

06-23-2009, 11:42 AM	#2
merlin5577 Banned Join Date: Nov 2008 Posts: 675	Does the truck have an EGR valve? If so pull it off and check it for carbon build up. Sticking EGR valves can cause the problem your describing.

06-24-2009, 09:28 PM	#3
cburcham73 Senior Member Join Date: Aug 2008 Location: williamsburg virginia Posts: 182	i'll yank it off tomorrow. i know when i take off slowly and then let off the gas real quick it will stall.

06-25-2009, 12:11 AM	#4
tjzz4 Senior Member Join Date: Oct 2007 Posts: 276	I agree.... You might take it off and put a piece of duct tape over the intake port and take it for a short spin.

06-28-2009, 04:33 PM	#5
cburcham73 Senior Member Join Date: Aug 2008 Location: williamsburg virginia Posts: 182	tested the egr,and blocked it off. to dice..could it be smog pump related. i heard of those things making the truck do weird stuff.