Mechanics

MISFIRES

1992 Pontiac Sunbird • 90,000 miles

Its a 1992 sunbird gt 3.1L it has been misfiring for the past few months I have changed the fuel filter replaced most of the fuel line new spark plugs and wires a new EGR with new mufflers ran injector cleaner non of this did anything any ideas?
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T.o.nero
September 16, 2012.



When does it miss?How bad does it miss?

Saturntech9
Sep 16, 2012.
Its starting to do it at an idle and it does it every turn of the engine if I floor it or just does it randomly it also has a knocking in the engine now

Tiny
T.o.nero
Sep 16, 2012.
At idle pull off a spark plug wire and put it back on do that with all the wires and see if the rpms drop on each wire you pull off. Becarefull not to shock yourself let me know what you find.

Saturntech9
Sep 16, 2012.
Alright I did what you said and I found out that it's one of the 3 in the back of the engine but I can't figure out what one cuz it doesn't misfire all the time

Tiny
T.o.nero
Sep 24, 2012.
So you can't narrow it down to which cylinder?

Saturntech9
Sep 24, 2012.
Ya I can't I know it's one of the 3 back ones not sure what one tho

Tiny
T.o.nero
Sep 24, 2012.
Cant you see or hear the spark shorting to ground anywhere?

Saturntech9
Sep 24, 2012.