Won't start.... Turns over very slow.

I have a 69 CJ5 with the Dauntless :v6:. Last year it ran fine with no issues but the brake master cylinder started acting up; the peddle would slowly go to the floor while at a stop light. Pumping the brakes would build pressure. So I parked the Jeep in the barn until I could get time to look into the brake issue.

Six months later I go to start the Jeep and it turns over very slow. Knowing the battery was weak I replaced it with the battery from my tractor but still the same thing. The engine would turn over about half a revolution. I then pulled the starter to see if it would spin the drive pinion gear fast enough to engage the flywheel. It appeared to be just fine. For good measure I picked up a replacement starter for $30 at the local auto parts store. Installed it, same thing... The engine would turn over very slowly.

I then pulled all the spark plugs. After doing this, the engine turns over several rotations but really slowly.

The next I will check is for a good ground to the engine block. All the fluids appear to be fine. What else should I check?

Thanks in advance for the suggestions.

 

Thanks for the suggestions.

The solenoid is attached to the starter and was replaced when I tried the new starter.

I have not tried it with the clutch in or out, at least not that I recall. I will add that to my list.

I too was thinking a plugged exhaust system.... Maybe a squirrel or mouse decided to move in or use it for winter storage.

 

Curious if it's a bad ignition switch. pull the ignition wires and try hot wiring to start

 

I experienced that exact situation with my '57. Might make it hard to start or have no power, but would not cause the slow cranking.
(In my case I had zero power above idle, but a lovely smell of roasted acorns.)

Not ignition switch, either. That powers the solenoid, not the starter motor itself. Possibly a cruddy solenoid? I would check all connections as said - and perhaps clean the starter brushes and commutator.

 

Removing the plugs takes the exhaust out of the equation.

How thick is your oil? Might want to consider changing the oil.

Battery up to snuff? Try push starting it and see if the problem clears up once it is running.

Was anything done that might have changed where your timing was set at? That can cause slow starter action.

 

Ooops. Sorry, it's been a long day.

Maybe he needs to drain the winter amps and replace them with summer amps.

 

All the magic has gone outa the smoke and now the electrical system is a muggle.

 

What about jumping a large gauge wire from one side of the solenoid to the other basically bypassing solenoid to see if it cranks stronger.

Or take and run the battery positive and negative directly to the starter to see how it cranks?

Try starting in neutral and clutch pushed. Mine cranks slowly sometimes until I realize it's in gear and I didn't push in the clutch. Basically normal I was just starting in gear

 

Thanks for all the great ideas! I did some troubleshooting last night and this is what I have found.

- I tried to jump start the jeep using my tractor. With the tractor running 14.5v... Turn the jeep key and it dropped to 5v. Would lead me to believe it was a weak battery. So I did the same jump start test with my truck; same results.

- Some asked about thick oil? The oil has less than 100 miles on it.

- I tried with and without the clutch pressed; same results.

- Ran the 4 gauge battery wires directly to the starter, same results.

- Someone mentioned accessories on the belt, There is only the alternator and water pump. I could move the water pump by hand but did not check the alternator.

What blows my mind is it ran fine when parked. So then I started tracing all the wires. Here comes the fun stuff! Something had been eating my electrical system. My tachometer wire has been eaten, the engine ground wire no longer has any insulation on it, and the vacuum advance line to the HEI is missing a few inches.

With that said... Even if the entire electrical harness was gone, going directly from the battery to the starter would have eliminated the slow cranking. Granted it would not start but it would at least turn over more than half a rotation.

It looks like I have my work cut out for me fixing all the rodent damage. But as far as the slow cranking, there must be something going on inside the engine. :?

 

- " I tried to jump start the jeep using my tractor. With the tractor running 14.5v... Turn the jeep key and it dropped to 5v. Would lead me to believe it was a weak battery. So I did the same jump start test with my truck; same results."

Is this with the key in the "ON" position only or in the "START" position?

 

The voltage numbers suggest the starter is trying real hard. What is preventing the engine spinning? Clutch plate frozen? Alternator jammed?

 

Thanks for the reply.

I haven't checked the alternator but I will...

If the clutch plate was frozen I would think the jeep would try to roll forward when cranking? I have the park brake set but I would expect a little movement.

 

The meter will read 14.5v in the ON position and drop to 5v in START position.