Car hesitates and backfires on acceleration.
11-18-2008, 07:02 PM
#1
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Join Date: Dec 1969
Location: san antonio texas
Posts: 146
Car hesitates and backfires on acceleration.
It's a '95 Z28. If I barely step on the gas to keep it at any speed it "bucks" and calms down only when I let it coast. When I accelerate at highway speeds, it sometimes backfires, after the "bucking" stops. It will accelerate, eventually. The air filter is brand new. What is going on?
11-18-2008, 11:07 PM
#4
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Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,677
Check for things like:
-dirty MAF sensor
-torn air inlet elbow
-burned or cracked plug wires
-worn plugs
-dirty fuel filter
-low fuel pressure
-weak coil
-faulty IC Module
-faulty Optispark
-etc.......
-dirty MAF sensor
-torn air inlet elbow
-burned or cracked plug wires
-worn plugs
-dirty fuel filter
-low fuel pressure
-weak coil
-faulty IC Module
-faulty Optispark
-etc.......
11-19-2008, 04:12 AM
#5
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Join Date: Jul 2008
Location: Paragould, AR
Posts: 58
If those all check out then you might want to check the O2s and TPS. Just a thought
11-20-2008, 09:31 AM
#9
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Join Date: Dec 1969
Location: san antonio texas
Posts: 146
Thanks for all the help. Guess I have some pokin' around to do. It is back-firing more the last few days. It has a K&N cold air system and I changed the filter but that did not help. I can't remember when the fuel filter was changed. Must be at least 7 or 8 years ago. How hard is that to change? The plug wires all look good but the plugs are also about 7 or 8 years old.
It bucks real back when I back up out of my driveway when the steering wheel is turned. Time to get some dirty hands.
It bucks real back when I back up out of my driveway when the steering wheel is turned. Time to get some dirty hands.
11-20-2008, 10:30 AM
#10
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Join Date: Mar 2006
Location: Kansas City, Missouri
Posts: 94
Fuel filter is pretty easy. Just make sure you release all of the pressure from the line, or you'll be getting a gas shower (a mistake I won't make again). There is a good write up somewhere on here.
11-20-2008, 11:02 AM
#11
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Join Date: Mar 2003
Location: Maryland
Posts: 1,147
IS the check engine light on?
Go buy a fuel pressure test gage.
It sound like you have not been maintaining your car. How many miles are on it?
If this was my car i would do a full tune up (opti, wires, plugs, O2's and so on)
Go buy a fuel pressure test gage.
It sound like you have not been maintaining your car. How many miles are on it?
If this was my car i would do a full tune up (opti, wires, plugs, O2's and so on)
11-21-2008, 05:34 PM
#13
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Join Date: Dec 1969
Location: san antonio texas
Posts: 146
I admit, I have not taken as good of care of it as I used to. Before getting married. I had an "exhaust leak" that I eventually found a few weeks ago. One of the hoses was rotted out. I found another one yesterday that is rotted out. Both on the bottom of the hoses, making it harder to see. I wiggled a few hoses and one fell apart
. Replaced that and no more exhaust fumes in the car
. The one I found yesterday is on the lower passenger side of the throttle body (a vacuum inlet) that leads to a silver "box" over the passenger side valve cover. The 3 inch hose is also rotted out. I have it duct taped for now until I get the $12
hose tomorrow. It didn't buck quite as much today but my tape job is not covering the whole connection. It also took a few tries to start the car after I reconnected the hose.
No telling how long it has been like that so should I be worried about anything being sucked into the TB?
. Replaced that and no more exhaust fumes in the car. The one I found yesterday is on the lower passenger side of the throttle body (a vacuum inlet) that leads to a silver "box" over the passenger side valve cover. The 3 inch hose is also rotted out. I have it duct taped for now until I get the $12 hose tomorrow. It didn't buck quite as much today but my tape job is not covering the whole connection. It also took a few tries to start the car after I reconnected the hose.No telling how long it has been like that so should I be worried about anything being sucked into the TB?
