RE: ihc-digest V6 #24

["Neff, Matthew John - MBA" <NEFMJ124@domain.elided>]

> ----------------------------------------------------------------------
> 
> Date: Thu, 6 Aug 1998 15:33:55 -0600
> From: rhughes@domain.elided
> Subject: Re: [Fwd: Passed emissions]
> 
> John, Harvesters,
> >>If I'm not mistaken, the power valve on the model 2210C can not "blow
> out"
> >>per se.  It has no rubber diaphragm (as on other Holley models).  It's
> >>possible it could leak... because it is a valve after all.  If it
> leaked,
> >>this would effectively enrichen your mixture off idle.
> 
> You're right, there is no rubber.  It is a spring-loaded valve.  I use the
> term "blow", because that's what people seem to usually say when referring
> to power valves.  Whether it actually was faulty, I can't be sure, but the
> spring in the old one seemed to have more play than the new one...  *And*
> the change to a new valve did correspond (along with the jetting change)
> to
> reduced CO.
> >>Have you bothered to check other things on your engine... vacuum leaks,
> the
> >>EGR system, PCV system, etc.?  Small problems can add up cumulatively
> and
> >>be difficult to track down.  Your carb changes might be covering up
> >>something else.
> 
> My vacuum hoses are good, but it's possible my EGR or PCV went bad
> sometime
> in the last several months.  Frankly, I never really considered these as
> possible culprits, as my problem was a rich mixture.  A vacuum leak or
> stuck EGR would *lean* the mixture, wouldn't it?
> >When I get my AutoMeter vacuum gauge installed, I'll be able to watch for
> >the power valve engagement, which should be interesting.
> >>The vacuum gauge moves around a lot depending on so many
> >>factors... mainly engine load and throttle position.
> 
> Bummer.  I thought it would be clear, given a certain vacuum reading and
> "seat of the pants" feel, when the valve opened.  Also, aren't the valves
> stamped with the in. of Hg at which they open?
> >Anyway, this guy seemed pretty confident
> >that something is wrong with the carb if I have to jet that small.  He
> may
> >be right, as this is an old, tired carb.
> >>Nope... I think they don't know what they're talking about!  That jet is
> >>not far from stock.  I'll try and remember to look up the stock jetting
> in
> >>the IH shop manual tonight and e-mail you what I find.
> 
> I've got the shop manual, but I've never seen the jetting discussed.
> Several times I've queried the digest as to what jets people run in the
> 2210C, and gotten no response.
> 
> >>The carb probably could stand to be completely disassembled, soaked
> >>overnight in carb cleaner and carefully reassembled.  You'd be surprised
> at
> >>the accumulated varnish and crud this removes.
> 
> I did a complete rebuild last year (in order to pass emissions).  That's
> why this year's problems were so frustrating.  My suspicion last year, and
> what I still wonder about, is whether the air bleeds are clogged beyond
> help...
> >Holley makes jets down to about .40, but they are kind of hard to find.
> >Lots of parts stores could order them for me, but no one had anything
> >smaller than .50 in stock.  This lends credence to what the speed shop
> guy
> >said, I think.
> >>I don't see what that has to do with anything.
> 
> Well, just that I would expect the jetting to be somewhere towards the
> middle of bell curve of sizes.  If I've got the smallest ones that are
> readily available, that puts me in the lower tail of the distribution.
> Obviously, that may indeed be the correct jetting, but if it is not
> correct, there really is nowhere to go but up.
> >You'll get *much* better information for your IH vehicle here on this
> list
> >than just about anyplace else.
> 
> That's for sure.  But I don't always have time to wait for an answer, etc.
> 
> Thanks,
> 
> rob h
> 
	Hi, Rob

	Are you sure you've got a 2110 and not a 2300? The former has a
power valve that is not removable where the latter has one that is.  If it
is the latter, they do have a tendency to 'blow out' as you said with a
good, solid backfire.  The 2100 has a little ball assembly that's an
integral part of the float bowl.

	Another thing to watch for when changing jets is the squirter valve
and the accelerator pump cam, which need to be changed out as well (if
changing jet size considerably). Again, if you indeed have a 2110, these are
integral to the carb and thus cant be changed.  Also- a good heuristic in
determining the size of the power valve you need is this: get a good vacuum
reading off of the manifold and divide this number in half.  Add .5 to this
value and this is the size you should use. 

	Later

	Matt Neff
>