Hey Mr. D,
Many thanks.

Hope YOU are well.

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

I gotta wonder if your backfire is actually misfiring in any cylinder and letting the unburned mixture go into the exhaust where it gets fired off. I've accidentally killed the ingition on a running /6 and also on a running Lycoming 4 cyl aircraft engine, then turned the ignition back on after <1 second, with some spectacularly loud backfires in both case!

For a good bang, turn off ignition, pump accelerator several times, and flip her back on...

One of the guys at collage living in the dorm loved to create a backfire when driving by a hot chick... now that I think about it, any chick. Yeah, he finally split the muffler lengthways. Fun stuff while it lasted.

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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

Hey Mr. NM9,
That's exactly what is suspected is happening, and that is the premise on which everything that has been done is based. In order, this is what has been done:

Removed and cleaned the ENTIRE Fuse Panel's Fuse Holders and installed NEW Fuses.

Checked and adjusted the Reluctor Air Gap from 0.012 to 0.010.

Cleaned each Distributor Cap Contact Point.

Confirmed continuity of EACH MSD 8.5mm Spark Plug Wire Circuit from Distributor Cap Contact Point to Spark Plug Clip (they all registered 3.5 to 5.7 on the Ohmmeter on the AUTO setting).

Removed, cleaned, and reset all six NGK ZFR5N Spark Plug Gaps to 0.045.

Installed a NEW NAPA Eichlin MO-3000 Extended Tip Rotor. And while it mitigated the backfiring, it didn't eliminate it.

In the process, it was found that the newly cleaned Distributor Cap Contact Points all had slight burn marks across them EXCEPT for Cylinder Number One's Contact Point.

What I'm hoping is that the Number One Cylinder's ZFR5N's Spark Plug is faulty.

Am scheduled to replace it this morning.

If it solves the problem then it will have been the culprit all along.

If it doesn't solve the problem, will replace the other five ZFR5N Spark Plugs.

Even the Choke Mechanism on the Bendix Stromberg Model W Carburetor was serviced and adjusted, and a NEW Air Filter obtained.

If all that has been done doesn't solve the problem, then there is something more esoteric going on. It could reach as far as the LX-301 Control Module failing intermittently, the Ford HEI Ignition Coil doing the same, the Mopar Electronic Distributor doing the same, possibly a broken Valve Spring, a bent pushrod, a messed up cam lobe, a faulty timing chain, and on and on. The possibilities are endless. Each more serious than the last.
There are some who do this just for the hell of it.

The strange thing about Lorrie's backfiring is that it isn't loud. It's just a gentle "poot... poot...... poot poot", intermittent and quite random. AND, it doesn't happen except when she's rolling. It doesn't happen at any RPM while standing still.

Have even considered that it may not even be a backfire from her mighty 225 Slant Six, but that it may be in the SureGrip differential, maybe the U-Joint, which have all been checked and found to have nothing apparently amiss.

Have even considered that this is just a little "trick" that Lorrie is playing on me as retribution for having let her sit immobile for sixteen years due to a severe illness.

Nonetheless, everything that has been done has been good for her. I suspect that what finally fixes the problem will be some subtle nuancial item. I say that because there is a tee-nincy clue that something really strange is amiss because while working on the Choke Mechanism, there was a strange little REALLY high-frequency "tweeeet" type sound whenever the Rod from the Coil in the Exhaust Manifold Pocket to the Carburetor Linkage was handled. I have no idea from whence THAT is coming.

Lorrie is such a complex and unique individual. I sometime suspect that she has somehow become embued with an actual "living" presence and does stuff just to get attention.

Anyway, thanks for the response. It is much appreciated.

Take care,

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

What have you done to free up the valves? If it has been sitting that long, it would not be at all odd for the valves to be sticking. The valve springs are not very stiff on these. Some Rislone or Sea Foam down the carb while may help the intakes. Not sure what is good for the exhausts. Pulling the valve springs 1 at a time and working gum cutter then lubrication in the guides is the sure way.

Hey Mr. NM,
What you are asking happened over two years ago. Went through an ordeal with all the Valves. Lorrie has been running just fine for a couple of years now. Sticking Valves is NOT the problem. If anything about the Valves themselves it would be that the is possibly a piece of carbon on the one of the Valve Faces keeping it from closing totally, but THAT would give a regular backfire. What she is experiencing is an intermittent, and totally random backfire.
Lorrie's sixteen year coma came to an end in 2012.
Had just put in a can of SeaFoam on Lorrie's last fill up. Also a half a can down the Carburetor.
Used the "Magic Rope Trick" on all the Stuck Valves back when THAT happened. Again, Stuck Valves is NOT the problem presently.

Will tell you the "immediate" problem. Have been sitting here for the past hour trying to get the Washer off of an NGK ZFR5N Spark Plug. Am no closer to having that happen than when I started!

Is there a trick to doing it? I'm wearing a set of 10X magnifying lenses, and still can't see why the Washer "cocks" in relation to the threads.

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

Hey All,
It's been raining this morning, but at about 10:45 a.m. the rain stopped, and provided a chance to change out Lorrie's Number One Cylinder's Spark Plug.

Got out one of the NEW NGK ZFR5N Plugs, removed the Washer, gapped it to match the other five Plugs, went out, pulled Lorrie's Number One Spark Plug, put in the NEW one, and went for a test drive.

There was absolutely no backfiring.

Got back and brought the old Plug in, wiped it off, and got to looking at it REALLY close through a 10X Magnifying Head Set.

Guess what! There are two barely discernable .50" long hairline cracks in the Porcelain above the Hex. If one runs a fingernail across them, they can be "felt".

Anyway, am going to let Lorrie cool off a bit, and then go for another drive like yesterday to see if the "poot.. poot..... poot poot" returns like it did yesterday.

Would have to say that those cracks are to electrons what the Grand Canyon is to a BB.

Am hoping that the problem is solved and that Lorrie is finally satisfied that she has a REALLY clean Fuse Panel, a NEW extended tip Rotor, a NEW Number One Spark Plug, and over a week of intense attention.

Will let you know what happens when we return from Lorrie's next jaunt.

Hope you all are well.

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

Hey All,
Went to pick up the results of last Monday's Blood Tests, and Lorrie is still backfiring.

Am going to prepare another NGK ZFR5N Spark Plug for Cylinder Number Six. Am waiting for Lorrie to cool down, then will install and test drive. If no backfiring, then will let her sit till tomorrow morning, and take her out again to see if she starts backfiring again.

If she does, will change out the other four Spark Plugs.

Then if she is still backfiring after that, will have to blame it on something other than the Ignition System, but don't know what.

Will be in touch.

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

I think you have finally cracked the case.

Bill LOL

_________________
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

Hey Bill,
CRACKED CASE? Oh, I hope not! But seriously, installed a NEW Spark Plug in Cylinder Six, and didn't even get out of first gear on the way to the hiway before Lorrie backfired.

Came back and parked her, came into the house and prepared the last four of the NGK ZFR5N Spark Plugs, and when Lorrie is a bit cooler, will install them and go for a test drive. If she backfires on the test drive, then the problem is NOT in the Ignition System. But I don't know where else to look.

Maybe next pull the Valve Cover and adjust the Valves.

Maybe it's the Timing Chain.

Maybe all the Cylinders are carboned up.

Maybe... something else.

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

You know; the case of the missing slant six...

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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

Hey Bill,
"Missing Slant Six"? Would you care to elucidate?

Was contemplating the situation last night, and the thought occurred to me that the whole problem might be water in the gasoline! Knowing the business climate here in deep east Texas, it is not outside the realm of possibility that in order to maximize profits, the place from which Lorrie's fuel is obtained might just be adding a few hundred gallons of H2O to the underground storage tanks when no one is watching.

Have asked a number of people here in the area if they had noticed that one of the three places to get petrol here sells three grades of the stuff, yet there's only one ground level filler port, and I've never seen but one truck putting gas in the underground storage tanks through that port.

Am thinking that maybe changing the fuel aquisition location this next fill up and maybe putting a premium grade through Lorrie's mighty (though farting) Slant Six might work wonders.

Anyway, will be installing NEW NGK ZFR5N Spark Plugs in Cylinders Two, Three, Four, and Five this morning.

Will let you know what the outcome of THAT is.

Missing Slant Six, huh?

JC

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Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

Just for you JC, because of your prosy posts featuring "St. Lorry of the short haul" are rather colorful and entertaining to read.

A skip, misfire, a miss, cracked plug porcelain, slant six, stupid puns, innuendo, irony, double talk, and so it goes, it's the way I roll.

Mystery of ill running (missing or misfiring) slant solved (cracked the case), turned out to be cracked plug insulation. = Case cracked of missing slant six. I know it's dreadful once explained, but I can't help my self, that crap just flows out of my yap endlessly... I never said any of it was particularly clever, just endless. LOL

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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

Hey Bill,
And here, I was in my consternative enigmatism completely missing your double entendres due to my misconception that the SSF is almost exclusively straight foreward, no-nonsense tech oriented! Geeze, I hate it when that happens.
Ahh so! It's all becoming clear!
The cryptic subtlty of it all escaped me due to my concentration on the seriousness with which this whole escapade has been imbued. I'm not usually so humorless.
I have to say that from now on, a response from you will be apprehended as a welcome oasis in an otherwise usually arid landscape of dry and generally no-nonsense diagnostic expertise.

It's always nice to find that there is some "depth" behind the literality of what is said.

As it turns out, probably what is REALLY amiss with my girl Lorrie, is that the way she is used and treated has been the origin of the difficulties. There was probably nothing wrong with any of the stuff that got replaced. The problem is most likely that she doesn't get driven very much because I have little occasion to do much moving around. She gets started, driven six or seven miles, parked for an hour or so, then restarted and driven home where she sits for a couple of days, only to have the same routine repeated over and over. And this goes on for what must seem to her like an eternity or forever whichever come first.

In doing some more research into the problem, have come to a circumstantially evidenced conclusion that her combustion chambers MUST be filled to the brim with carbon deposits.

What she NEEDS is to be taken out and driven at full tilt for a while, which for Lorrie would HAVE to mean being driven at highway speeds in second gear, since in third gear, she, having all the aerodynamics of a cinder block, is incapapable of exceedng 60 MPH, at which time her mighty 225 Slant Six is barely turning at an estimated 3500 RPM when it needs to be up at five grand.

Have a number of times driven her at a bit over 50 MPH in second gear, and her mighty Slant Six seems to revel in the chance to "stretch out" a little. It sounds and feels good. But in my empathy with her, since we both are quite a distance "over the hill" as far as age is concerned, keeps me from pushing her too hard for too long.

The saving grace in the past has been that once a month she had been getting driven, at the most, a forty mile round trip to Livingston and back which served to mitigate the carbon buildup.

But in the past couple of months, that has not happened due to some unusual circumstances.

So next Tuesday, have scheduled a trip to Livingston, which will be done in second gear both going and coming.

And there are also some unconventional remedies that MIGHT get applied in the process. I hesitate to delineate what they are at this time due to some of the reactions to some of the other unconventional things that have been revealed about Lorrie's care and keeping.

As it now stands, Lorrie is probably more fit and better adjusted than she has been in many moons, and the only thing wrong with her is that she has been treated much too gently for much too long.

Anyway, thanks for the responses, and I promise not to be such a prude in the future, at least as far as YOUR posts are concerned.

Take care,

JC

_________________
Lorrie Van Haul - 1967 Dodge - P200 Post Office Vehicle - 225 Slant Six - Torqueflite A727 Automatic Transmission - Right Hand Drive Steering - Big Three HEI System - Frantz Oil Cleaner System - Bendix Stromberg Model W Carburetor

There's the old water trick to get rid of carbon...........


http://slantsix.org/forum/viewtopic.php?t=24198

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes