Sandy,
A check of the valves is a compression test. A gauge is only about
$15 at the WalMart, and it's good enough for the home garage workbox. To
use the gauge, warm the engine, then remove all sparkplugs. Screw gauge
into #1, spin engine on starter for a couple of seconds. Read and record
gauge reading. Do same to #2, etc. Then you compare the pressure
readings. One wants them to be within 10 percent of each other for best
engine performance.
Low readings can be caused by worn rings or by valves not sealing well.
To test for ring wear, pour a tablespoon of motor oil into the
low-reading cylinder(s) and repeat the test. The oil tends to seal
temporarily the worn rings, so pressure on the gauge will be higher. If
the oil doesn't affect the reading, it's probably a poorly sealing valve.
If the valve is leaking, you _may_ be able to hear a hiss if someone
turns the engine with a wrench and you listen with your ear at the
exhaust manifold. If it's leaking badly, you probably won't hear a hiss,
however.
Before taking the head off, you want to be sure that the valve
adjustment is correct (not too tight). It's not that head removal is all
that difficult (it's not) but there is no point to opening an engine
unnecessarily.
You wrote that you replaced the distributor. Did you replace the cap
too? Your timing light, when connected to each ignition wire in turn, is
flashing evenly and equally? Spark plug color and deposits are the same
on all four?
Bob
On Fri, 5 Mar 2004 22:20:03 -0500 "H. W. \"Sandy\" McCullough"
<hwmccullough@earthlink.net> writes:
> Ok, gang, several have given valuable input to this ongoing dilemma
> and
> each piece of input has been valuable and appreciated, however the
> engine
> miss is still present.. Here's where I stand so far:
>
> Plugs replaced
> Plug wires replaced.
> Points and concensor replaced.
> Distributor replaced.
>
> I'm thinking at this point some of you who had the wisdom to point
> out a burnt valve may have been on target. I had hoped that wasn't the
> case, so I tried the above options, hoping I would not have to yank the
head
> off for re-work. But, I guess I have no other option at this time
unless
> anyone has a better idea.
>
> That being said, what are my next steps?
>
> As always, each and every suggestion is greatly appreciated.
>
> H. W. "Sandy" McCullough
> 72 B
> 68 B
> http://www.mgcars.org.uk/pics/mccullough72b.jpg
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