Backfire/Short? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Iowa · 05-12-2003, 01:58 PM

My son drove my pickup last weekend and said the truck backfired
and blew the muffler...it did. Also he had to jumpstart a couple times to get home.(Alternator not charging). Thinking that was the problem I replaced alternator, wife took this morning and lights went dim after a couple miles and backfired, started chugging, she said she had to run with lights off to work. (not good idea but she had to get to work). Every time she turned lights back on it would backfire very loud and act like it wanted to die. truck is 84 chevy 3/4 ton 4x2 with 5.7 350. Anyone have any ideas? Thanks

TIMSPEED · 05-12-2003, 02:13 PM

Sounds like either some of the ignition has went bad, or there's a MEAN short somewhere....

Iowa · 05-12-2003, 02:46 PM

After work I will look for short. There used to be a second battery for 5th wheel hook-up I will trace that. That could be a MEAN short. Ignition? could that draw enough power to starve the plugs? The backfire has throwing me through a loop. Thanks for the quick response.

**old Rusty C10** · 05-12-2003, 06:26 PM

check by your exhaust manifolds and make sure no wires or anything is close i had a ford that woudl short out that way

Iowa · 05-13-2003, 09:11 AM

Thanks everyone. The brown wire to the alternator had a bare spot and was grounding. Taped and all ok right now. I have drove about 60 miles and no backfire of stall.

05-12-2003, 01:58 PM	#1
Iowa Registered User Join Date: Feb 2003 Location: Iowa Posts: 6	Backfire/Short? My son drove my pickup last weekend and said the truck backfired and blew the muffler...it did. Also he had to jumpstart a couple times to get home.(Alternator not charging). Thinking that was the problem I replaced alternator, wife took this morning and lights went dim after a couple miles and backfired, started chugging, she said she had to run with lights off to work. (not good idea but she had to get to work). Every time she turned lights back on it would backfire very loud and act like it wanted to die. truck is 84 chevy 3/4 ton 4x2 with 5.7 350. Anyone have any ideas? Thanks

05-12-2003, 02:13 PM	#2
TIMSPEED Join Date: Jan 2003 Location: Modesto, CA Posts: 1,321	Sounds like either some of the ignition has went bad, or there's a MEAN short somewhere.... __________________ I have a few cars... See Them Here

05-12-2003, 06:26 PM	#4
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	check by your exhaust manifolds and make sure no wires or anything is close i had a ford that woudl short out that way __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

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05-12-2003, 02:46 PM	#3
Iowa Registered User Join Date: Feb 2003 Location: Iowa Posts: 6	After work I will look for short. There used to be a second battery for 5th wheel hook-up I will trace that. That could be a MEAN short. Ignition? could that draw enough power to starve the plugs? The backfire has throwing me through a loop. Thanks for the quick response.

05-13-2003, 09:11 AM	#5
Iowa Registered User Join Date: Feb 2003 Location: Iowa Posts: 6	Thanks everyone. The brown wire to the alternator had a bare spot and was grounding. Taped and all ok right now. I have drove about 60 miles and no backfire of stall.



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