Hi, guys:
I've got a real problem on my hands and have been trying to solve it off and
on for the last 3 or 4 weeks. #4 cylinder on my Tiger appears to be as dead
as a hammer. Here's the background on what led to this.
I performed what I call a "mini" engine compartment restoration which included
restoring the cooling system (cleaned radiator, new water pump, hoses, etc.),
pulling the intake and valve covers and cleaning them up (Edelbrock F4B and
finned aluminum Tiger valve covers), replacing the carburetor with a new
Holley 465 cfm unit, and doing a major tune up (points, plugs, condenser,
rotor, cap and wires). After I get it all back together, it runs like crap
with a steady miss on #4. I have the timing advanced a little since the
engine has the Ford C9OZ-C cam and the dwell angle is right on. I have chased
all the electrical gremlins I know to chase and have determined without a
doubt that the #4 plug is firing. I have run a compression test, both static
and running. Static compression is 142-143 across all cylinders and running
compression is approximately 70 to 75 across all cylinders. The only thing I
can see that is different on the running compression test is that the
compression on #4 is just a fraction slower to come up than the others. I
have also run several types of vacuum tests on the intake. Depending upon
rpm, it is pulling 15" to 18" of vacuum. I have also checked for an internal
vacuum leak by blocking off either the PCV hole or the oil filler neck on the
valve covers and checking the other to see if there is any sucking of air.
There is none. I've also pulled the valve covers off again and checked to see
if there was anything wrong in the valve train. Everything appears to be okay
and all rocker arms appear to have the same range of movement as the engine is
cranked over.
Guys, I'm at a total loss here. I've been fooling with small block Fords now
for over twenty years and have never been baffled like this. I'm damn near to
the point of giving someone a helluva deal on a Tiger (just kidding...it feels
good to get that off my chest, however...). Am I completely missing something
here? As you can well imagine, any help would be greatly appreciated.
Stumped,
Andy Walker
B382001600
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