Is there anyway a reluctor could cause a weak spark to just one cylinder? It got dropped onto floor a few time during recurving several years ago.

I have one cylinder that tends not to fire off with same gusto as its brothers when listening from exhaust exiting rear of car. It sounds like a lope generated missed beat at idle, tends to diminish as rpm increases, and gone by 1800 rpm.

Or, could this missed beat indicate lower compression in that one cylinder which is somewhat overcome by increased savaging at higher rpm? At last compression test, #4 required two additional revolutions to come up to nominal pressure compared to the other five. A squirt of oil in cylinder produced 190 psi in just three compression strokes where normal unoiled range is 160 psi for this engine.


Note:
#4 plug shows a similar correct color in relation to its five brothers. Valves are not leaking confirmed by pressure testing with manifold removed this spring.

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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

Could be lower compression. If the dist shaft is bent or reluctor is not perfectly round, then 1-2 cylinders might be affected.

I had what sounded like a dead cylinder at low RPM last weekend at Bristol, and the dist gear shredded on the way home and was clearly unevenly worn. I have not diagnosed whether the gear was causing this.

Lou

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Home of Slant6-powered fun machines since 1988

Just FYI: another Mopar guy found that his car would run fine with 1 ign box, but not with another that was known to be good. We found that the air gap at the reluctor was a little to big - reset it and all was well, which just shows variations among various stock replacement boxes.

Many reluctors I measured weren't uniform from point to point, but still seem to work fine; I'd just set the largest gap to spec and verify that the others didn't actually hit anything.

Last time I had distributor on bench, there was no side to side shaft play, and reluctor/pickup air gap measured the same for all six vanes.

I’ll swap in old orange box that came with car that I replaced during a head-fit over a malassembled distributor causing 180 degree out of phase spark distribution, and excessive hair pulling… Don’t ask it was dumb…. dumb, real stupid allowing Murphy to take over the wrenches.

What I have noticed since owning this car, as the distributor is cinched down compressing “Oâ€￾ ring, timing advances several degrees due to helical gear depth on cam.

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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

The timing on mine creeps also as you tighten down the dist. I Usually set it a few degrees past where I want it and tighten it down. Works everytime.

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82 D150-225/727
02 Dakota-3.9/5 speed
87 GMC C7000-8.2 Detroit Diesel/5+2

That is the drill I have been following, it’s just hard to park timing on a predetermined number. My engine is real picky at idle to a slight timing change in relation to rpm.

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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

x2 here, OEM reluctors a bit better but I check all the dizzys I work on...most of the time I find one tooth is a bit longer than the others...

-D.Idiot