Possible Ignition Problem

[Wreckless Warren]

I had the Galaxie out over the holiday; it loves the clear cool air. The exhaust note was strong, not missing a beat and the throttle response was real crisp. I took it out again Sunday and it ran the same way, cruising between 2500-3100 with a few wasteful displays of acceleration (out in the country BTY).

Then I started to notice small spits & pops in the exhaust note but I didnt feel anything different, know what I mean? I was about 10 miles from home by then so I aborted the ride and turned around. I got the revs back up around 3K and it sounded like it was started to break up although again I didnt feel it.

It seemed happy at 2100 (did't miss a lick) which is about 40 mph so I limped it back home. By the time I got it home it was not crisp at all, in fact it acted like a cylinder was almost out. I cant work on it till Thursday, 1st thing is look at the plugs. It wasnt puking any smoke and I didnt feel any loss of power so I dont think its fuel related. From the sounds of it Im thinking ignition, which consists of a new MSD Pro Billet distributor, a 13 year old (10K+ mile) MSD 6AL and equally old Blaster II Coil. Does this sound like an MSD box going poo poo? As always, thanks for you imput. ww

[jayb]

Checking the plugs is the right first step, to see if you have a fouled one.  My experience with MSD boxes is that when they go, they quit altogether.  Coils can certainly go out gradually, though.  If you are suspecting ignition I'd be looking at swapping in a coil next.

I wouldn't rule out fuel at this point either, a clogged fuel filter will make a car behave kind of like you are describing.  Or, a weak fuel pump that is slowly losing pressure.  Check the easy stuff first, Warren...

[WConley]

It could be dead simple, like a spark plug boot backing off.  Years ago I experienced a similar thing while going for a ride in a friend's 352 Galaxie.  The #8 boot was barely hanging on.

Here's hoping it's a simple fix!  I'm with Jay in that I doubt it's the MSD box.  The whole engine would be quitting momentarily if the box or primary ignition harness was having problems.  I guess marginal fuel pressure could be the culprit, given the lean spits and pops you were hearing.

[My427stang]

Flip the cap up first, look under, check the rotor contact where it the coil wire feeds, check all the wires are seated, then start pulling plugs.

If you see any thing that looks different an Ohmmeter is your friend for checking wires.

[Ted]

I'll suggest throwing a timing light at it and double checking that the timing hasn't moved.  While the distributor itself may be moving or the internal guts are binding, the MSD box going on the fritz will sometimes move the timing.