2.25 not firing 3&4 ?

[Lance]

I don't have a ground strap from chassis to the motor but the neg. from the battery goes straight to the engine. We just cleaned it, was pretty greasy. Should it have one from the motor to the chassis?

[Lance]

What voltages do you guys get if you put your meter across pos. & neg. terminals while running. Mine stays at 4.5 volts...very steady.
When I do the same measurment on an old jeep I have, the voltage jumps around very fast/unstable voltage.

[Nium]

Bonding straps are necessary

One side of the battery should be connected to the chassis directly next to the battery by a short thick piece of wire. If your rig is positive earth then the "+" terminal of the battery will be connected to the chassis and the negative side of the battery will go to the starter solenoid. If it's negative earth then the "-" side of the battery will be connected to the chassis and the positive side of the battery will be connected to the starter solenoid.

The chassis is suppose to be the "earth" connection point for all electrical "ground" connections. Using "earth" and "ground" is a bit of a misnomer here because there is technically no connection to earth or the ground in an automotive DC electrical system but since it's the commonly accepted terminology lets go with it. Modern vehicles and Landys from negative earth make onwards use the chassis as the negative connection point to the battery and the "hot" or positive connection point to the various electrical components (lights, windshield wipers, ignition coil, etc) are made through the starter solenoid, to the fuse block, to the ignition switch and outwards from there.

If the only connection to the "earth" side of the battery is to the engine that would mean that the rest of the electrical system in the rig is isolated from the "earth" side of the battery except for the electrical path of least resistance back to the "earth" side of the battery. Which could be through the accelerator linkage, ignition coil, etc. because the engine is electrically isolated from the chassis by the rubber motor mounts. If you have the Green Bible (part # AKM8159) please refer to page 38-N figure "Fig. N1-28 Layout of general electrical equipment, negative earth systems. Series IIA 4 cylinder models. From vehicle suffix 'D' onwards" you will notice "Item 14. Lead, starter motor to earth" and "Item 20. Cable, battery to earth".

I would suspect there use to be some sort of bonding strap from the engine to chassis or transmission to chassis (which wouldn't work nearly as well) a PO had installed that has broken since you had reported your issue started all of a sudden and not slowly.

To make the long of it short. Yes, there should be an electrical bonding strap from the engine (one of the starter mounting bolts for example) to the chassis and the "earth" side of the battery should be attached to a clean, bare spot on the chassis next to the battery.

As a quick experiment to check if this could be the root cause of your troubles attach one clip (the black) of a set of jumper cables to a bare spot of metal on the engine (away from the fan or moving parts) and the corresponding lead (black one) at the other end of the cables to a clean, unpainted piece of metal on the chassis. See if it causes your issues to go away. If yes then you definitely need to install an engine to chassis bonding strap or reroute how the battery connects to the chassis.

If I wrote things that you already knew my apologies.

Cheers!

[Lance]

I have a couple grounding straps here in the garage that I bought for something else but never used. I will install one this week if possible. (almost limited to weekends now).
I have seen a few guys refer to "The Green Bible". Is this better than the Hatnes manual?
Thanks for the help.

[Lance]

I attached a ground strap to a tab on the battery tray between the battery & oil bath air filter. Looks like it was made for it. The strap that was on the Rover is long and had a bolt hole in the middle, worked out perfect to ground the chassis & motor with one strap. Still didn't fix anything but it needed that anyway.

[SafeAirOne]

Have you considered an exorcism?

[Lance]

No but I have thought about pushing it off a cliff !

[yorker]

No but I have thought about pushing it off a cliff !

Haven't we all?

FWIW I run a ground strap to the chassis and to the engine from the battery, I know it is overkill but I have always felt that extra grounds aren't a bad thing.

[bmohan55]

If you do an exsorcism won't that just drive out "The Prince of Darkness", which would lead to more troubles?

[Nium]

Disconnect the wires to the coil and measure the coil resistance from "+" to "-" terminals on the coil. Would have been nice if the ground strap had fixed it.

With the coil wires all connected and the engine not running but the ignition turned on.

With the points closed you shouldn't measure any voltage on the distributor side of the coil to ground and battery voltage from the other side of the coil to ground.

With the points open you should measure battery voltage on the distributor side of the coil to ground, may have to leave the DMM on the post for a few seconds to see it, and battery voltage from the other side of the coil to ground.

[Lance]

I have checked the coil resistance, it is a "Flame Thrower" that I bought with the pertronics....the resistance is 3.0 ohms. I'll check the voltage across the points.
Also I'll through this out there to think about. This has happened twice, In the morning when it's cold I need full choke and pump the pedal a few times. When it starts it sounds pretty good for about 10 seconds then it's back to misfiring again & then thats it for the rest of the day.

[Lance]

I do have battery voltage when points are open & .25 when closed.

[Apis Mellifera]

Hang on...do you have points or a Pertronix?

You say that you need to choke it to start it then it runs for 10 seconds then misfires the rest of the day. Are you making choke adjustments? Are you driving the truck with the choke on all day? Does the misfire change with choke adjustments? You also say it's not firing on 3 and 4. Are you driving the truck on two cylinders?

[Lance]

I am not driving, haven't driven in months & the choke is used just to start it in the morning for my day of troubleshooting. I have two distributors, the old lucas with pertronics & a new one with points. The points distributor is in it now but I have tried the pertronics a few times thats why the flame thrower coil, I figured I would buy the pertronics & new coil at the same time.
It will run on 3&4 if I unplug 1&2. In my troubleshooting I have found it will run on any two cylinders but only two ???

[Apis Mellifera]

Have you changed the coil since this started or are you still using the Pertronix?