Volt meter 101

[Mr. Jones]

I've had this for a some time and the best I can do is sit and wonder,"How the f does this thing work?"
I'm needing to check the voltage or amps for my dist.I don't know what setting to put it on,which holes to plug the probes into or which wires to start checking??????
My 66-350 is torturing me,like the recent posts of danimal and oregon my 300 is refusing to start.This has gone on long enough that I finally had enough,walked away and let it sit.Then a couple weeks ago I pulled it up to my neighborhood service station.A few days later I got the call,"Your truck is ready,come get it."The mech.said the contact plate was loose in the dist.and he replaced the dist.set the timing.Well it ran perfect,started instantly,idled smooth,had power,got up to speed ,no back fires.
Three days later I start it up to go to work,started and ran perfect for about ten seconds.Then it started coughing,blowing out white smoke,and firing on three cylinders.Went up talked to the mech.He told me to clean the plugs,all six were black but not fouled.No good,didn't start.Yesterday I pulled the carb top off,checked the float action by emptying the bowl and cranking it a couple times ,floats rose,needle valve seated itself,fuel flow stopped.This is a Holly 1940 one barrel,as simple as a carb.can get.
The things I've done. 1) Remove fuel tank and check for rust,spotless and shiney.2) Check all hard fuel lines,ran a wire thru them,replaced rubber lines.3)Replaced fuel pump and filter.4)Replace carb with a rebuilt unit,from BFIC Fuel Systems 4)Replaced dist.O'Rielly unit(had the loose contact plate,whatever that means) and plug wires.Installed new battery,Inter-State 850cca.
When it all works,there's harmony.I don't understand why one moment it running sweet as can be then just fall on it's face.
Where do I begin?Any help would be appreciated.
Thanks in advance,
Dan

[Toyz]

To check voltage, red lead plugs into DC 10 a (red port on your left), other to COM; move the dial over to "20" under DCV; ground the black lead and hook the red lead to the voltage source. It's a good practice to check at the battery first to verify the meter, same procedure, red to Positive, black to Negative.
Rather than list all other test procedures, just go to the Innova website for specific instructions.
Your symptoms still point to an electrical problem, as you have probably surmised. The plugs may in fact have become fouled; replacing them may be a good starting point. Run a jumper wire from the distributor body back to the battery negative terminal, a jumper cable will serve well, to determine distributor grounding. Check the condenser mount and lead for any looseness.
I'm not sure what was meant by "loose contact plate" , but recurring symptoms may well represent the same root problem, ie, something in or at the distributor. If the movable contact point mounting plate is indeed loose, it may be varying the point gap, and hence dwell.
Just the basics for now; run a battery voltage wire to the + plus terminal of the coil. The usual caveat applies, if the vehicle starts, it may not shut off until the jumper wire is removed. If your O'Reilly's is user friendly, ask if they can test your coil.
Other than that, check all grounds; may want to replace both points and condenser, also. I'm certainly not an advocate of replacing parts unless they are suspect, especially with a recurring problem, but in this situation, it may be warranted.
You're certainly welcome to call if I can assist! Let me know and I'll p.m. my number.
Paul

[SC1966]

That's a good multi-tester. I think you plug the red lead into the red circled port on the left marked DC and the black lead into the center port. What you need is a timing light.

It sounds almost certainly like your timing slipped. Maybe the mechanic didn't tighten down the distributor mounting bolt, or maybe did not tighten down the contact points enough. I would check the timing. For that you need a timing light not a multi-tester. Or you can start the truck and very slowly try to turn the distributor one way and then the other and see if it smooths out.


EDIT----I think Toyz beat me to the punch...

[F7BIGJOB]

You should put RED lead on RIGHT side port for voltage [ see the icons ] left side is to read amps only.