My dart suddenly started running rough. It seems like a miss or a vacuum leak. I checked the plug wires, I have an alternative set that I know is good, swapped them over, same thing. Checked for vacuum leaks, can't find any. Dizzy hasn't moved, so I don't suspect timing, but I'll check that tomorrow as well.

I'll pull the plugs tomorrow, check those, also the dizzy, see if anything looks weird under the cap. The engine only has 3500 miles on it; most components are fairly new; no issues prior to this since the rebuild.

It'll idle OK, a little rough, out of gear, but in gear (automatic) it gets really rough. Starts fine, plenty of spark. At idle, at the tailpipe it sounds like a misfire to me, but I can't be sure.

Any ideas besides spark, fouled plugs or vacuum leak? Checklist to go by? Drives OK on the highway, but I have to put it in neutral at stop lights to keep it from running really rough.

Brian

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Fuel level problem, or crud in idle circuit.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Politicians, It's about that time to change the gas formulation isn't it.

I pulled the plugs, 3-6 are burning clean, but #2 looked like it wasn't firing there was nothing on it and it was wet, and #1 looked about half like it was firing. I swapped out those two for new plugs and it runs a lot smoother but still not what I'd expect, a bit rough. Maybe I was running on four, now five?

The cap contacts are copper and clean, the button looks good. Should I check the reluctor gap, any chance it's off just enough for #1 and #2 to be sporadic?

brian

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would that also explain my sporadic non-starts (which I thought was the ignition switch)? Maybe it really wasn't getting enough spark sometimes?

b

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maybe move to "electrical" bin

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The gap is .008, checked with a brass feeler. Seems uniform for all points.

What else would make one (or two) cylinders not fire? Recall, I tried a different set of plug wires.

brian

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If you've got a timing light, you can hook it up to each plug wire one at a time to verify which cylinders are getting spark.

Also, I hate to say it, but have you checked your valve lash? Valve hanging open could keep one cylinder from firing.

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I did adjust it about 2000 miles ago. I can pull the tin and check it again.

brian

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I checked with the timing light, all cylinders are hitting. I'll take it for a test run, maybe I just had two fouled plugs...

b

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Well, after changing out those two plugs it runs fine. Must be the bad gas issue mentioned above. I took her out on the highway, plenty of power, idles at the stoplights, no issues.

brian

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