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PostPosted: December 4, 2017, 7:00 pm 
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JD,

In a previous post you describe the problem as "It comes and goes. When it decides to shut down the motor, it does. Mis-fires appear and disappear like ghosts in a Scooby-Doo cartoon." That doesn't sound like "it's in the timing chain/gear/camshaft area" to me. How can fixed mechanical gear train generate an intermittent problem? You should rethink this before tearing the engine apart.

Best of luck finding the problem, Bill

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PostPosted: December 5, 2017, 11:32 am 
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BHRmotorsport wrote:
In a previous post you describe the problem as "It comes and goes. When it decides to shut down the motor, it does. Mis-fires appear and disappear like ghosts in a Scooby-Doo cartoon." That doesn't sound like "it's in the timing chain/gear/camshaft area" to me. How can fixed mechanical gear train generate an intermittent problem? You should rethink this before tearing the engine apart.
Mornin' Y'all-
I appreciate all the input, and agree with most of it... OK, all of it... OK, I know y'all are smarter than me... :mrgreen:

Symptoms? It would be easier to list what it didn't do!

As noted, it would shut off suddenly and not re-fire. It would develop a serious miss, then run fine in the pits. Sometimes, it would shut off and when you tried to re-start, you'd swear it suddenly had no compression. Then, an hour later, it would run fine. At one point, it was one plug wire off from where it should fire, then it was worse, like almost 180 off. Then it was OK.

When I first installed the new manifold and carb, Earl came down to set up the carb for me, brought his box of Holley parts and about 25 years experience with Holleys. He couldn't get the damn thing to run right and diagnosed a bad gasket between the manifold and the heads causing a vacuum leak.

So, I took all that off the block and heads and looked at the gaskets, which looked OK, best I could tell. But I replaced 'em anyway. Still wouldn't run right (stalling, spitting, backfiring, etc) and would shut off from idle and take three or four tries to get it running again. It would crank best with the fuel pump off. We installed a new, "low pressure for carburated engines" fuel pump and new lines and tried the next night.

We had plenty of fuel in the tank. Checked that at The FIRM and again in the shop, when I pumped most of it out so I could install the new fuel pump and new fuel line from inside the tank all the way to the carb. (Before you ask, Yes, I did pour it back in. :mrgreen: )

Finally, on Saturday, after re-doing the jets and some of the o-rings and such in the carb, it was almost running right. Almost... Still spit back and stuttered occasionally. James suggested I run it up and down the road and get things warmed up and maybe blow the cobwebs out of the carb, even though he'd rebuilt and cleaned it twice now.

It ran, sort of. Kept cutting off when I let off of it and would spit back thru the exhaust or the carb when revved. Earl made adjustments on every pass up and down the road. Then, it backfired hard thru the carb and shut off. Sounded like no compression again. We had fuel, perhaps too much. We had spark, perhaps out of time. We had no running engine. :evil:

At that point, we pushed it into the shop and called it a day. The re-naming ceremony took place about 30 minutes later. I haven't touched it since.

And that's the story.

Bill, I understand your point about a "fixed mechanical gear train" shouldn't cause an intermittent problem. Key word is "fixed"... Given that these symptoms have persisted through 3 distributors, 2 PCMs, I think all the sensors have been replaced (Yeah, new ones don't always work. True dat...) and a completely new intake/throttle body/injector/MAF system. It's almost down to "What's left?" Perhaps a pin is sheared off raggedly in a cam gear and catches in the right place some of the time or a timing chain is slipping cogs randomly or a broken cam that spins sometimes or... Well, I don't know... I'm pretty much guessing that any of that is even possible.

But, like I said, the entire batch of injectors, PCM, sensors, etc, was in a box and not on the car so they didn't do it. The New-old-stock DuraSpark was sparkin' and the Holley was carburating and the Dog A$$ Slotus still wouldn't run.

I'm open to suggestions...

Peace, Love and The DOG A$$ SLOTUS-
JDK

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PostPosted: December 5, 2017, 12:57 pm 
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Distributor drive issue? Or perhaps call an Exorcist?

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PostPosted: December 5, 2017, 1:25 pm 
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seattletom wrote:
Distributor drive issue? Or perhaps call an Exorcist?
Hi Tom! If you mean the gear that's ON the distributor shaft, well, I've had three distributors in it, all of which looked OK when removed. If you mean the gear on the cam that turns the one on the distributor gear, yeah, that's one of the things we're thinking might be the problem.

Lonnie has already given me a lead for an "excorcist" of sorts... Look back a page or so, you'll see him! :mrgreen:

:cheers:
JD

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"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


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PostPosted: December 5, 2017, 1:34 pm 
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GonzoRacer wrote:
seattletom wrote:
Distributor drive issue? Or perhaps call an Exorcist?
Hi Tom! If you mean the gear that's ON the distributor shaft, well, I've had three distributors in it, all of which looked OK when removed. If you mean the gear on the cam that turns the one on the distributor gear, yeah, that's one of the things we're thinking might be the problem.
I was thinking the one on the cam. IIRC, in the Cheby world there was a bad run of those drive gears that were creating all sorts of timing problems. 'Course yours is a Ford, so maybe that guy with the chicken feathers and cigar might be required...

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PostPosted: December 5, 2017, 2:04 pm 
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JD,
I am assuming you did a vacuum check for intake gasket issues ? And new gaskets are square on all surfaces? All rocker arms and valve adjustments are spot on ? If all these are good and cyl cranking compressions are equal, I would change the cam to a known good cam and start over again. It may have a bad timing gear and or bad lobes on some cyls. Get all the basics set and timing chain spot on and test again. Good luck ! Dave


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PostPosted: December 5, 2017, 2:49 pm 
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Hi JD, I commiserate with you!! Seeing that it will misbehave when sitting there, I would keep a timing light on the front pulley (damper) and watch what the timing is doing. Another thought would be cross firing either thru the cap or plug wires. Just my $0.15. Kartracer

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PostPosted: December 5, 2017, 3:08 pm 
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JD
Along the lines of Kartracers comment, is it possible that the key on the lower timing gear has given way? Just a thought.
Waltj


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PostPosted: December 5, 2017, 3:52 pm 
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When the carb was rebuilt did the float get changed? Sometimes floats don't live up to their name. That causes some hard to diagnose problems.

As Horchoa says. 'If man built it, man can fix it'.

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PostPosted: December 5, 2017, 8:20 pm 
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I'll add another armchair diagnosis. It sounds like your troubles started with a warm engine. When cold it ran well. Did you have any valve work done? Perhaps you have to little clearance between valve stem to guide, causing a sticking valve or two at temperature. BTW, bronze guides need more clearance than OEM guides.

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PostPosted: December 5, 2017, 8:51 pm 
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well J.D.

you are in a pickle aren't you,

first i must say everybody is truly trying to help but with all new ignition and fueling it is probably mechanical.

my best guess is a broken crank!

check where the pistons are when turning the engine clockwise and then counterclockwise, you may find that the pistons are out of time.

what engine are you using?

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PostPosted: December 6, 2017, 9:52 am 
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JD,
Check your entire ignition wiring harness for shorts. Change the coil and check its wiring.
I Had a coil on my corvette work well until it got hot and then it started breaking down with mis-fires.
Good luck.


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PostPosted: December 6, 2017, 11:22 am 
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A useful non-invasive test is to hook up the timing light and rev the engine from idle to 2500 or so, watching the timing marks. The mark will move at different speeds depending on throttle position and vacuum, but it should move smoothly and repeatably. When you let off the throttle it should move back; it might be a sudden jump, but it should be repeatable.

If it jitters around or does the cha-cha, you might have a loose timing chain.

While you have the timing cover off, pry under the timing gear or cam nose to check cam bearing clearance. The clearance should be no more than .003", though .005" might be a more realistic service limit.


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PostPosted: December 8, 2017, 2:44 pm 
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Yo!
I must confess that I have not ventured into the shop in a few days now. It is possible that the Dog Ass Slotus has healed itself and is running fine now. Doubt it, but it's possible... :mrgreen:

Like Mr. Hennessey says, y'all are trying to help and I appreciate it. In no particular order...
It's a new coil.
It's all new wiring/connectors etc.
Sometimes it does seem to appear when the car warms up and go away after cool-down, but not always.
It well could be the key on the timing gear, that's one thing I want to investigate.
We checked float levels and fuel shut-off several times via the "peepholes" on the float chambers in a Holley.
Had a new cap, new plug wires and a whole new distributor in the last several weeks.
Oh My God, not a broken crank?!?!?! Sure hope that's not the diagnosis... :(

Soon as I get a break from work and holiday preparations, I'll get out there and take a look and report back with some (hopefully) new data.

:cheers:
JDK

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Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


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PostPosted: December 8, 2017, 5:07 pm 
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ford 302's have a habit of crank breaking and block cracking, just sayin'

especially with 50oz counterbalanced cranks and non Mexico blocks.

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