Re: [MV] Out of ideas... M151 still misses

From: JTravis (dagobert@ix.netcom.com)
Date: Sat Feb 05 2005 - 08:30:23 PST


Crazy as it may sound, have you considered that it MIGHT be a blocked
exhaust manifold? That would still let it pump and allow for all the
listed symptoms, but it would also inhibit airflow. It might be a big
chunk of carbon build-up on the inside of the manifold. Or not.

Or one other thing (you aren't going to like it)- have you checked the
other cylinders for all these problems as well? Where you think it is
number 1 missing; perhaps the miss is in one of the others and you are
getting a harmonic reaction that just makes it seem to be coming from
number one instead? (Again, it would explain what your work is telling
you) Granted, I'm not there, and I could be WAY off base. But that's
one thing I've learned over 25 years of spinning wrenches; that if a
problem is unsolvable and you have checked "everything", that you
usually have overlooked one detail or another, and usually it's the one
that you're first to say "Aw, it CAN'T be THAT; I already elinimated
that from the start!"
Good luck with it. If physics and mechanical engineering fail to fix
it, I guess we can always resort to Voodoo and Magick next. Anyone got
a spare live chicken?

Jay

Mil-Veh Co. wrote:

>First, thanks for the fouling info., Joe, Cliff and
>anyone else who may still provide info.
>
>
>
>OK, just one more question and this is giving me fits,
>I'm still having a problem with a dead miss. Here is
>what I've done to correct a "no fire" in number 2
>cylinder on the M151:
>
>1. R/R spark plug with new plug, could see decent
>spark, but still no combustion. Plug smelled of gas,
>but not wet with gas. (also checked plug wires for
>firing order, Firing Order: 1-3-4-2 )
>2. Did compression check, 105 lbs...passable, all
>about 105 lbs while cranking. (new is about 135 lbs.)
>
>3. R/R plug wire with new wire.
>4. R/R dist. cap with new cap.
>5. Replace entire Prestolite electronic distributer
>with new unit and replaced all wires with
>new...getting desperate!!!
>
> Still missing on #2!!
>
>6. Replaced spark plug again, just to double check.
>7. Removed valve cover, observed engine running,
>rocker arms moved up and down smoothly and checked for
>.....
> a. Broken valve spring
> b. Loose or broken push rod
> c. Proper lift on valves looking possible cam
>lobe damage. (all fine)
>
>8. Checked to see if cam had somehow skipped time,
>engine was TDC on #1 when at the timing mark on crank
>pully..can't be cam timing.
>
>9. Made sure batteries were fully charged and proper
>ground. No problems, they're new and wiring new, all
>tight and no corrosion anywhere.
>
>Everything seems fine, just noticed that the
>compression was a little low, but within range for an
>older engine.
>
>10. I can't think of anything reasonable that it
>could be...now thinking its something unreasonable...
>
>
>
>Considered a foreign object (mouse, bird, rag, etc.,)
>may have somehow entered the intake manifold during
>the carb rebuild and is not allowing combustable air
>into number 2 hole..but then I did get good
>compression, so is that likely???? I'm running out of
>ideas, good ones, bad ones, I've been over this engine
>a dozen times and can't find a thing wrong.
>
>If I can't figure out anything else, then I will pull
>the intake manifold and look into the head for some
>sort of obstruction. I mean, what's left to check,
>right? Arrrrrgggggh!
>
>
>



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