misfire/rough idle/lack of power - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Byronic · 02-09-2010, 03:28 PM

99 silverado 5.3l
I started it the other day and it felt like it had half power. It would idle at 500rpm. When I speed up it would sputter and I could hear popping in the intake area. I turned it off and restarted it again. It ran fine.
Today it did the same thing. I turned it on and off several times before it was back to normal.
I checked all the connections I could see.
I'm guessing something in the computer is not connecting every time I start it.
Any idea where to start?
Thanks

ed2552 · 02-09-2010, 07:04 PM

MAF Sensor dirty?

Black 95 TSI · 02-09-2010, 11:13 PM

Is the check engine light on? I have seen a few trucks and vans with 02 sensors causing misfire problems.

Byronic · 02-10-2010, 07:35 AM

Check engine light never came on. Yesterday I went across some train tracks and it sputtered and popped . I got it home and went through all the connections I could see. Unplugged and plugged all I could find. Started it up, same issue. Turned it off and restarted it, works fine.

clinebarger · 02-10-2010, 12:36 PM

Check the fuel pressure, Key On Engine Off 55-62 psi.

02-09-2010, 03:28 PM	#1
Byronic The Beach Cruiser Join Date: May 2009 Location: Panama City, Florida Posts: 358	misfire/rough idle/lack of power 99 silverado 5.3l I started it the other day and it felt like it had half power. It would idle at 500rpm. When I speed up it would sputter and I could hear popping in the intake area. I turned it off and restarted it again. It ran fine. Today it did the same thing. I turned it on and off several times before it was back to normal. I checked all the connections I could see. I'm guessing something in the computer is not connecting every time I start it. Any idea where to start? Thanks __________________ 1999 Silverado DD 1966 Panel Truck 2003 Harley Road Glide 1967 Schwinn Tandem Single Speed

02-09-2010, 07:04 PM	#2
ed2552 Registered User Join Date: Jan 2007 Location: Charles City IA Posts: 1,626	Re: misfire/rough idle/lack of power MAF Sensor dirty? __________________ '67 C20, Under the Knife!, LWB, Eaton HO-52, Rear Coil Springs 72' GMC C2500, 350, TH400(?), Dana 60 '67 K10 4-spd., 305, SM465, Dana 44, 12 Bolt, RUST! '65 C60 292, 4 spd, 2 spd Rearend, 15' Grain Box, MINT! 09 Yukon Denali 82k Miles 6.2L/6A

02-09-2010, 11:13 PM	#3
Black 95 TSI Registered User Join Date: Jan 2007 Location: Alexandria VA Posts: 77	Re: misfire/rough idle/lack of power Is the check engine light on? I have seen a few trucks and vans with 02 sensors causing misfire problems. __________________ 70 C10 SWB stepside forsale 00 Silverado Z71 Sold 95 Eagle Talon TSI turbo (Hellz ya its fast) 70 Chevelle 69 firebird 10 Silverado 4x4

02-10-2010, 07:35 AM	#4
Byronic The Beach Cruiser Join Date: May 2009 Location: Panama City, Florida Posts: 358	Re: misfire/rough idle/lack of power Check engine light never came on. Yesterday I went across some train tracks and it sputtered and popped . I got it home and went through all the connections I could see. Unplugged and plugged all I could find. Started it up, same issue. Turned it off and restarted it, works fine. __________________ 1999 Silverado DD 1966 Panel Truck 2003 Harley Road Glide 1967 Schwinn Tandem Single Speed

02-10-2010, 12:36 PM	#5
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: misfire/rough idle/lack of power Check the fuel pressure, Key On Engine Off 55-62 psi.



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