Missing/Power Loss!

[jonnyc]

OK, truck (Series 3 88", 2.25 gas) was fine when I drove to work today and shut it off. Started it up this afternoon and it is stuttering and missing(?), sounding exactly like an old VW. Temp gauge was up a bit and there is a significant power loss. It seems to idle ok, and there was nothing obviously loose around the engine, but there is a definite loudish stuttering somewhere around the engine area. My vacuum gauge was down to about 16 (from its usual 20) and bouncing a bit. To round out the picture, I have a Rochester 1 bbl. and a Crane ignition.

No time to dig into it now as I'm off to Philly to hopefully see the Sox win tonight! Papi should be playing first and I don't want to miss that! I will start to diagnose the problem tomorrow afternoon, and I hope you gents can provide some direction above and beyond what I already plan to look at.

Thanks in advance.
Go Sox!

[dunerunner]

Sounds like a timing issue to me...

[ArlowCT]

Been real humid around here lately. WD40 the dizzy cap, check your clearances and give it another try.

[ignotus]

Read this page it may help. http://www.series2club.co.uk/pages/technical/lucas.html

gene

[jonnyc]

Timing seems ok; starts and idles just fine. I'm going to hope for a simple electrical glitch.

BTW, Sox won, and...........Yankees lost!!!! Other than the Rover it was a wonderful day.

[dunerunner]

also, check the rotor cap for tracking and cracks. When was the last time you replaced the distribution wiring harness?

[jonnyc]

I'll throw in some spare cap and rotor I have. What exactly do you mean by the "distribution wiring harness"?

[dunerunner]

Your high tension wiring from the coil to the rotor cap and plug wires.

[jonnyc]

Oh, ok. I thought you might mean the bunch between the Crane unit and the coil. I have a spare set of what you mentioned also. I'll rotate bits out in the AM.
Thanks.

[jonnyc]

Update:
I swapped out the cap and rotor, and checked all the wires and plugs. Nothing seems obviously wrong. There is no water in the oil or oil in the coolant, as far as I could tell. The stuttering/popping noise is coming out the top of the carb as rhythmic backfires that increase and decrease with engine speed.
Do we still think electrical?
Sticking valve?

[dunerunner]

Still sounds like timing..... Intake valves are open when the plug fires..... Timing chain??

[jonnyc]

I won't rule it out, but I think a sticking valve(s) might do the same thing. I put in new timing gear system about 6 or so years ago, don't want to do that again.

[dunerunner]

Could be a broken valve spring... Nothing is easy at this point!

[dunerunner]

I would verify the firing order around the rotor cap, just in case someone is playing with you...

Then do a compression test before pulling the rocker arm cover.

[jonnyc]

"Could be a broken valve spring... Nothing is easy at this point!"

I don't want to jinx it, but after about 15 years with it, more often than not it is really something relatively easy. Yes, there have been a few painful fixes, but.........(he says with his fingers crossed)