Annoying problem

[42swing]

I have developed a starting issue with my '42 MB. 6v system, no modifications, Battery reads 6.43 v at rest, all connections tight. When cold I pull the choke out all the way, throttle about 1/2 inch, switch on, and crank. Engine cranks slowly and haltingly, like its struggling against compression or I was hand cranking it. Doesn't turn over like say my '42 Ford Sedan (also 6V), but then never really has. After 3-4 tries it will start then run fine, good power, good oil pressure, good temperature, generator indicates charging. When hot or warm, no choke, throttle 1/2 inch and crank. Same halting, slow crank. May start after several tries, but often will not start at all until the engine cools off completely.

Bad starter? Any help greatly appreciated.

[Farrell Fox]

How old is the battery? Sounds like it's losing cranking amps.

[dinof]

Have the battery stress tested. I agree with Farrell. Check all grounds for good/clean contact.

[artificer]

Where are you? Helps others when one has their approximate location set in the user panel, as Dino & I do for example.

If mid summer your Jeep starting technique is a little off.
Mid summer, 2 accelerator pumps then foot right off the pedal, should be adequate for starting with a Carter carburettor & engine in good tune.
Solex no pumping & about 1/2 pull out of the enrichment cable.

Holding the accelerator pedal 1/2 open as is implied, when trying to start @ any time, is not suggested.
This reduces manifold vacuum applied to either brand's carburettor idle port.
The idle port is what is supplying fuel & needs full manifold vacuum when starting.
The only time to use the accelerator pedal during cranking is right down if flooded or immediately after the engine starts.

Have you tuned or done anything engine related on this Jeep recently?
As described could well be timing too far advanced.
To check, see if the starter turns the engine over more quickly with the ignition switched off.

Let's know, but in the meantime here is something to check out:
http://www.jeepdraw.com/images/Starter- ... 8.3.15.pdf

[cjv-35]

Also check your starter brushes for if they are more than half way worn, they should be changed in my opinion.

[Chuck Lutz]

1) battery charges up but no longer holds its original cranking amps = go have it tested at NAPA
2) timing
3) insufficient/painted surfaces = poor grounding
4) missing ground straps

..but since it seems you have done nothing recently to alter the timing, ground straps, etc., then I too believe the battery has seen better days.

The industry seems to have a really GOOD feel for how long they will lat. By that I mean if you have a five year warranty and the five years are up you probably should check that FIRST...easiest, fastest and cheapest (they test for free!)

Remember, you don't want to know what just the voltage is....the cranking amperage is what you need to know.

[42swing]

Thanks very much guys!!

Couple additional facts:

O location is outside Philadelphia, PA. Temp is around 80.

O I've not done anything to the engine like timing, etc.

O checked all the grounds which seem to be good.

O battery is at least 5-7 yrs old, I've been getting 3ish out of my others.

O just had another go, same scenario

O I'm thinking it's been getting slowly worse over time.

I'm really liking the suggestions it's the battery, makes a lot of sense to me, particularly since it's probably twice as old as those in my other cars. Off to NAPA tomorrow...

[dpcd67]

Your timing is too advanced; those are the symptoms; retard your timing a bit; use a vacuum gauge.
And your battery is too old.

[artificer]

Good to see someone is learning, especially about proper diagnosis rather than guessing.
Just because a battery is old doesn't mean it is cactus especially if left on a trickle charger.
When checking the battery remove the battery caps & observe the cells when cranking a bad cell will bubble. NO NAKED FLAMES.

[tamnalan]

How's your starter switch? Perhaps the foot switch is bad. Mine was dropping just over 1 volt across the switch.

I was talked into getting one of the new $65 repro switches instead of a cheapie. Wow! I'm glad I listened.

Ron sells them.

[dpcd67]

The type 1 6V batteries with the most CCAs are sold by Batteries Plus.

[42swing]

So, took the battery to NAPA yesterday and had it tested. Voltage was down slightly, but cranking amps were very low. Also noted the top was bulging slightly at the - terminal post. At 7 yrs old at least it didn't owe me anything, so bought a new one while there to get the core credit.

Back home and installed this morning, plus checked all the grounds again. I must say, didn't seem to crank over any faster, but started right up. Shut down and went to get a coffee then tried again - previously it would not have wanted to restart, but fired right up. Shut down, and tried again - started right up.

One thing I forgot to mention, occasionally it will fire but not catch, the Bendix will disengage, and I can hear the starter whirr, so it is spinning the starter OK when it's not under load. Also crank speed is the same whether the ignition is on or off.

So issue seems to be sorted, I wonder if I'm just expecting too much on the cranking speed? Next time I'm at an event I'm going to listen to a couple othe Jeeps start to compare. Also going to check the timing.

[conrod6]

Crank the engine over without the ignition on - if it cranks smoothly and steadily like this and haltingly / with difficulty with the ignition on then the timing is too far advanced.

regards Barrie

[Farrell Fox]

[Post Deleted By Author]

[42swing]

Barrie,

The engine cranks the same with the ignition on or off - no difference.