intermittent missfire/backfire
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intermittent missfire/backfire
Hello everyone,
I have a problem. Last december I rebuilt the 305 in my 84 berlinetta. I failed smog ( yes I live in california) so I took it to a shop. They told me I needed a new Catalytic Converter and a Thermal Vacuum Switch. Cool replaced them. passed smog and no problems until last weekend. I was heading out of town and on the freeway the car started to act like it was missing real bad and when I pushed the gas pedal down it would get worse and even backfire. This has happened 3 times since last saturday and I can't figure out why.Wires are good, plugs too, so I checked the Accelerator Pump in the quadrajet and it seems to be working as well. I am running out of idaes. BTW the cat was installed Thursday and I got it back on Friday.
Please Help,
Trevor
I have a problem. Last december I rebuilt the 305 in my 84 berlinetta. I failed smog ( yes I live in california) so I took it to a shop. They told me I needed a new Catalytic Converter and a Thermal Vacuum Switch. Cool replaced them. passed smog and no problems until last weekend. I was heading out of town and on the freeway the car started to act like it was missing real bad and when I pushed the gas pedal down it would get worse and even backfire. This has happened 3 times since last saturday and I can't figure out why.Wires are good, plugs too, so I checked the Accelerator Pump in the quadrajet and it seems to be working as well. I am running out of idaes. BTW the cat was installed Thursday and I got it back on Friday.
Please Help,
Trevor
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
That is usually an ignition problem. Do you have a tach? If so, is it acting weird during these events?
The typical culprit is the ignition module and/or coil, which are both part of the distributor (the coil being in the distributor cap). That's assuming your distributor cap and rotor are in good shape (you didn't mention them as being "good").
The typical culprit is the ignition module and/or coil, which are both part of the distributor (the coil being in the distributor cap). That's assuming your distributor cap and rotor are in good shape (you didn't mention them as being "good").
Thread Starter
Junior Member
Joined: Oct 2009
Posts: 31
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Re: intermittent missfire/backfire
That is usually an ignition problem. Do you have a tach? If so, is it acting weird during these events?
The typical culprit is the ignition module and/or coil, which are both part of the distributor (the coil being in the distributor cap). That's assuming your distributor cap and rotor are in good shape (you didn't mention them as being "good").
The typical culprit is the ignition module and/or coil, which are both part of the distributor (the coil being in the distributor cap). That's assuming your distributor cap and rotor are in good shape (you didn't mention them as being "good").
UPDATE: Today as I was driving home from work the car started to bog down again. This was not a missfire, but more like a clogged cat. But like I said before the cat was just replaced. Should I go back in and see if is somehow clogged? Also all day yesterday I had no problem with the car it ran great all over town. Timing was good as of last Friday when I picked it up from the smog shop. I am LOST.
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