Sudden and mysterious death. Lucas again?

[bthompson]

Well, it finally happened. Rough running became hard start, became no start. Maybe you guys can help me diagnose!

<span style="color: #990000">Backstory:</span> It began with an intermittent miss in hard rains, accompanied with a fluctuating tach needle, last summer. A few months ago my electrics started dimming, most notably the right headlight. Then I noticed the miss was getting worse under <span style="font-style: italic">any </span>electrical load. A week ago, It would stumble noticeably with the turn signals or brake lights. Brake lights plus turn sigs would kill the engine. Then it ran with a stumble with the lights on, and <span style="font-style: italic">anything </span>else would kill the engine. The battery seemed sluggish, as if it wasn't charging fully. An overnight trickle charge didn't affect the problem.

<span style="color: #CC0000">Troubleshooting:</span> Air+fuel+spark=run.
Air: I checked the intake manifold, and the bottom two nuts were loose to the point that the clamps were free. Tightened them back up, resolving a possible air leak. Valves are adjusted. Compression is good.
Fuel: Checked the fuel pump for adequate delivery. Check. DGV accel pump squirts. Check.

That leaves spark. I've replaced the cap, rotor, wires, and plugs recently. I have the Pertronix in the the dizzy. I get a spark from the coil upon cranking. The spark timing is correct.

<span style="color: #CC0000">Observation:</span> The battery shows full voltage. The alternator light on the dash does not light until the engine dies completely. I take this to mean the alternator/battery relationship is working. I get 9v from the battery under load, and 7v at the solenoid. The solenoid gets hella hot while cranking. It cranks slowly, but doesn't catch -- not even with a shot of starting fluid.

I'm stumped. There's not a lot that gets in the way of the ignition circuits. The lead from the batt goes straight to the solenoid, from there to the coil, from there to the dizz, from there to the plugs. How can accessories kill the primary voltage that easily?

Possibilities: Weak battery? Wouldn't that show on the dash light?
Weak coil? Spark is spark; but not enough to light off ether?
Weak connection? The only real junction is the solenoid. Not enough juice to spin the engine I could see, but the coil is sparking, which means the secondaries are getting juice, and the pertronix is tripping.

What am I missing? I've gotta be overlooking something easy. Heck, <span style="font-style: italic">everything </span>is something easy in a Midget. I've ordered a new solenoid from Moss to be on the safe side, but I'm gonna be rather bummed if that doesn't do the trick.

 

[JPSmit]

what happens when you try to start? does it turn over? does it click? Can you put a screwdriver over the solenoid bolts - what happens then?

You could try swapping the battery with one from another car - or even boosting it. Or get the battery boosted.

sounds more electrical than anything.

do you have a multi-meter to check if it is charging? (once you get it running)

is your ground strap connected and adequate?

 

[61frogeye]

A while back I had an electrical problem that would kill my BE when I hit the high beams. It eventually got so bad that it killed the car if I turned on anything electrical, even when I hit the brakes or honked the horn. Then the car would not start. After some serious sanding and cleaning up of all the electrical connections from the battery and to the ignition switch/solenoid and the ground straps etc the problem was gone.

 

[David_Doan]

The combination of your symptoms points to poor grounding. With the engine off and the lights on, check the voltage at each light and at the battery. If they are not the same trouble-shoot from there. I'm predicting you will find at least one bad ground.

 

[nomad]

Check the battery posts for corrosion first. Your voltage readings should be higher. That does not mean there aren't some other bad connections probably headlight grounds as was mentioned.

Kurt.

 

[bthompson]

JP; it turns over but slowly. Same by shorting the solenoid bolts, same after an all-night charge. I have a multimeter, but never bothered to check the charging voltage since the dash light never glowed. Alas, too late now. Haven't checked the ground strap yet. Where is it on a 1500? (embarrassing -- I should know that! :blush: )

Dave T., that's just what mine's been doing. I looked closer just now: the solenoid battery bolt is rusty and grunged up, and looks like the futz got into the battery cable lug. 'This might be it,' thought I, and went to tighten the nut down. No motion -- rusted solid. Tried to remove the nut to clean the connections...

...and promptly snapped the bolt off and shattered the solenoid housing ... Guess I'm gonna need that new solenoid after all. Hopefully, that, and some more grounds cleaning, will work.

 

[RickB]

It's good to spend part of a day and just clean them up.
Not sure if your's is like mine but I have a heavy ground wire attached to the firewall above and to the left of the battery.
It goes down to the block, I think it's also connected at the bolt for the starter. (IIRC)
Mine's a bit custom though, so yours might be different.
It's a good idea when you find it to remove the fastener and clean that area up.
Then you also will want to clean connections.
I find a 22 barrel cleaner brush (the copper or brass type) in a cordless drill is great for cleaning the inside of the female bullet connectors.
Then wherever you find grounds do likewise, clean so you have bare shiny metal where they connect.
Replace grody fasteners.
Make use of stainless steel fasteners where corrosion is a problem.
Bad Grounds will sink your boat. BTDT too many times.

 

[JPSmit]

Sounds like ordering the solenoid was a good idea!

the ground strap on a 1500 comes off the front of the engine down low and attaches to the cross member the steering rack is on, It is about 3/8 wide mesh woven metal.

 

[61frogeye]

I went over everything connecting to the battery, posts, ignition wire at battery post and the ground strap to the firewall and every surface of the bolts and connectors and firewall surface until they showed fresh metal. On my BE there is even a wire mesh ground strap bolted between the trans and body.

 

[MichiganTed]

Check the voltage drop between the battery positive terminal, solenoid, and starter. Then check the voltage drop between the battery ground, body, and engine block to isolate the power drain / poor connection. By measuring voltage drop you don't need to take anything apart. You only need a decent volt meter. There is a good discussion on voltage drop at:

https://www.aa1car.com/library/voltage_drop_testing.htm

When you get her running, voltage should be between 13.8 and 14.2 volts, warm idle, lights and heater blower on.

 

[Bob Claffie]

If one of the diodes in the alternator is bad the ignition light will BARELY glow so as to be unnoticed. This could be adding to your lack of electricity. As above, you do need a lot more voltage. Bob

 

[Bayless]

One more note. When you clean all those connectors, add a little dielectric grease before reassembling. Then they will not be so prone to corrode in the future.

 

[bthompson]

Thanks for the suggestions, gents -- I got her running today! Thanks, Ted, for the info on voltage drop. I'd only ever tested for continuity before.

The bulk of the problem <span style="font-style: italic">was </span>in fact the solenoid bolt: apparently it was so gummed up with corrosion hiding behind the little rubber boot, it was choking everything off. The alternator couldn't get amps to the battery, the battery couldn't get amps to the starter, and hardly anything was getting through to the accessories. (I s'pose since the alt and batt were equally choked, the dash light didn't see enough of an imbalance to light off.)

The new solenoid came from Moss today, and it's all happy and shiny. I took a wire brush to the battery leads, brightened up all the connectors, and <span style="font-style: italic">whoo-ha!</span> the difference was immediate. It lights off immediately, and has noticeably more power. (Amazing how these cars can frog-in-a-teakettle you over a few months.)

So that's 90% of the problem solved! It's not perfect; there's still a hint of a stumble with (lights + turn sigs + brakes), but I'm fairly confident that I can voltage-drop-test that problem out over time.

I got my headlights to equal brightness -- that was just a loose bullet connector. D'oh!

An odd thing: turns out my engine ground strap isn't a braided cable. It's a battery-style cable with lugs on both ends. Aftermarket, I presume?

 

[aeronca65t]

On a related note, years ago I had a running Mini that was a parts car.
When I'd start it to move it, the thing would turn over slow unless I jiggled the throttle up and down.
One day the throttle cable went up in flames.
The correct ground cable had been removed and the engine was grounding through the throttle cable!

 

[JPSmit]

An odd thing: turns out my engine ground strap isn't a braided cable. It's a battery-style cable with lugs on both ends. Aftermarket, I presume?

glad it works! and, yes, sounds aftermarket!

 

[61frogeye]

On a related note, years ago I had a running Mini that was a parts car.
When I'd start it to move it, the thing would turn over slow unless I jiggled the throttle up and down.
One day the throttle cable went up in flames.
The correct ground cable had been removed and the engine was grounding through the throttle cable!

The choke cable and braided battery ground strap (+earth) on my BE are in close proximity and I am certain that they touch occasionally. Might that be a problem? It is a stock 948 and it appears original but......?

 

[MichiganTed]

Choke cable to ground wouldn't cause any issues unless your grounds are weak. Just check for voltage drop between the battery negative terminal and the vehicle body then again between the engine block. A drop of more than say 0.2 volts between the battery neg and engine block - and you have a poor ground strap to the block.

What do measure across the battery while the engine is running with all electrical loads off? Then re-measure with all electrical loads (lights, fan motor) on? You should measure between 13.8 and 14.2 volts in both cases. Less than that and the charging system is suspect.

 

[bthompson]

Measuring across the battery, I get a good strong 14½v with no load. The weird thing was, I added lights, then blower, then turn sigs, then brakes...the engine started faltering and missing, and finally died under the load...but the battery was reading 14+v right up till the end!

So, charging system A-OK. Guess it's time for the voltage-drop game to find where the leak is.

 

[bthompson]

I had an odd sort of breakthrough today that's worth mentioning.
90% of carb problems are electrical, they say...well, it seems like this electrical problem is at least part carb!

The stumble under electrical load led me to check the timing. The consensus online is that DGVs like anywhere from 14°-20° advance at idle, so I made sure I was around 18°, and checked the idle and mix while I was at it.

Surprise! The idle mix screw had been vibrating itself out against its spring. Instead of 1¼-1½ turns out from seated, mine had backed out to 3¼! :eeek: I re-set it and the idle screw for a nice smooth 900 rpm. (The idle screw has to be 1½ turns into the throttle lever to run...I should probably look at a richer idle needle at some point, to get closer to half a turn.) Or MAYBE I'll just chuck it all out the window and stick an HIF-4 in there...

With the mix set right, the electrical stumble has all but disappeared. It's still leaking voltage, but at least it's not killing the engine now.

 

[MichiganTed]

Nice