98 lumina #1 misfire

outlander

NAXJA Forum User
Location
Columbus,Ohio
Hey guys I need help with my DD.
3.1 litre 98 lumina .

The idle is rough and performance has suffered....shows a code for cylinder #1 misfire.Also seems like fuel economy is down also.

soooo.......

I replaced the ignition control module and #1 coil pack with units I got from the junkyard that tested good by the local parts drone.Also verified that fuel pressure was to spec.Plugs and wires changed also.
Still runs the same.

What else would cause this thing to have this problem?Stuck open injector?(wouldn't that cause the fuel pressure to be low?)I pulled number one plug and it was damp while the others had a nice gray color to them.......
 
It's likely damp because it's not firing...therefore fuel is just hitting the plug but not burning off. My Focus has a similar problem, but it's not throwing a code or anything.

P.S. This really should be in OTHER Tech instead of non-tech.
 
Had a problem with my XJ with the valve sticking causing the plug to carbon up and not fire. Would run a can a decarbon crap through it and the problem would be fine for like a month then it would return. Finally got it narrowed down and taken care of. Since you've already changed things electrically my guess would be a valve or a problem with the injector.
 
you probably should replace your plugs... or at least clean the dirty one off with solvent and a stiff wire brush, blow it dry with an air compressor (to blow any particles off too!) regap it to spec, and reinstall. I used AC Rapidfire and loved them on the 3400 in a Pontiac I had, I think there is a NGK plug with a similar design but costs a little more, good results from those from what I've heard as well. Don't run bosch +2, +4 or some gimmicky stupid plugs like that with more than one electrode.
 
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