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)

[Boston]

KISS method.
Pull the dizzy cap. Check the points are ok. Once pulled into the garage and car was fine. Yet car wouldn't run the next day.
Points had broken up. How the hell it ran before is beyond me.

[jonnyc]

I have a Crane ignition in there, but I will check for any broken bits.

[dunerunner]

What did you find out?

[jonnyc]

1. Son left for TX and I now have a spare Cherokee.
2. End of the school year and I have no possible excuses for putting off grading.
Hope to check the firing order first tomorrow, and then look for debris in the dizzy, and if nothing, I'll probably adjust the valves. With the rocker cover off I can see if there are any obviously damaged valve stems or springs.

[dunerunner]

Ugh!! Grading.....

Was just curious....

Best!!

[o2batsea]

Vacuum leak? You said the vac was down. See if there is a bad connection or loose fitting around the carb. I'd also be sure the dizzy is locked down, but it probably isn't timing.

[Erik M.]

Vacuum leak? You said the vac was down. See if there is a bad connection or loose fitting around the carb. I'd also be sure the dizzy is locked down, but it probably isn't timing.

Check for splits or cracks in the vac hose, too.

[printjunky]

I just went through a similar 5-day ordeal with loss of power in a similar system (88, 2.25, gas, pertronix, Rochester 1bbl) under load (uphill), and after eliminating EVERYTHING once (new wires (did observe some arcing with old wires), new plugs, new coil, timing checked, valves set, compression check, vacuum checks (did fix a vacuum leak, as well), NEW FUEL PUMP (electric) all new fuel lines, pickup tube checked, tank vent checked) it turned out that my brand new out-of-the-box fuel pump was not pushing enough volume. The first clue that I FINALLY clued into was that when it would sputter and die, the filter (clear, up top, easily visible) was EMPTY of fuel. A 42GPH fuel pump will FILL a filter! So problem solved, eventually.

So I would add fuel pressure/volume to the list. Though I'd not bother with a gauge, if it were me, I'd just unhook the line from the carb and watch it (probably point it right at the top of the carb!). If plenty of fuel seems to be flowing you're probably good. If it seems weak it's probably starving (thirsting?).

Big upside, my daily driver got a helluva tuneup. Man, does she purrrrrrrr!

[jonnyc]

Added, thanks!