Engine slow turnover

[crieders]

Engine turns over very slowly when cold and needs to be done at least twice before will start. In subsequent starts when warmed up is fine. Batteries are fully charged. I thought I would check wiring first. All looks connected but I am wondering if anyone has posted on how to trouble shoot this type of thing? Thanks very much.

[Stu Jackson]

Cliff, It sounds like the engine isn't "hot" enough to start at first, so consider adding a solenoid for the glow plugs.  Otherwise, hold the glow plugs in longer.

[Ron Hill]

Cliff : Besides the soleniod mentioned by Stu, you need to check all of your battery connection to make sure they are CLEAN and tight!!

Especially check the negative ground wire attached to the engine block (bell housing)!!

A few thoughts

[jonathanc34]

I had slow crank and intermittent start issues as well.

It was definitely my engine block ground. Once I replaced that, no further issues.

[crieders]

the engine block ground? now all I have to do is to ID that one. any suggestions for that? Thanks

[KWKloeber]

Engine turns over very slowly when cold and needs to be done at least twice before will start. In subsequent starts when warmed up is fine. Batteries are fully charged. I thought I would check wiring first. All looks connected but I am wondering if anyone has posted on how to trouble shoot this type of thing? Thanks very much.

Cliff

The FIRST thing I would do is determine the voltage AT the starter (solenoid "B terminal"; the pos battery cable terminal ) and AT the battery bank WHILE CRANKING cold (obviously that takes more than 2 hands) with a reliable voltmeter.  From there I could narrow down the cause.
That means an independent ground wire back to the battery to measure the +V at the starter.

Obviously if you see really rusted/corroded or loose cable lugs they need to be taken care of. But I do not start messing with things until I determine as well as possible the cause. Otherwise the end result is there could be multiple things wrong, and you never catch and fix the root cause.

Check to make sure all glow plugs are functioning by feeling the side, you shouldn't be able to hold onto them tightly.  You said she turns over slowly, so I don't think they would be problem there, but surely make "catching" easier.

During your fix up, move the battery negative cable (what others call 'ground') from the bell housing bolt to the starter bolt - your engine will appreciate that upgrade. They are both metric M8 bolts so no change is needed to the cable lug. You might need a longer starter bolt to make sure you get enough threads engaged. Play that by ear.

Troubleshoot, Troubleshoot, Troubleshoot - then fix/repair/replace.

[mark_53]

If you have the OEM wiring, it is not robust enough to stand the test of time. Numerous connections and long cable runs will eventually cause problems somewhere along the line for you to troubleshoot time and again.  Install a dedicated start battery with short cable runs to the starter.

[Stu Jackson]

...............
Install a dedicated start battery with short cable runs to the starter.

I keep reading this somewhat misleading recommendation.  Moving a battery so it is closer to the starter is just as valid as putting that battery in a central location and sizing the wire properly.  The battery doesn't have to be moved if the wire is sized correctly.  Of course, the further away the battery is the larger the wire.  My point is that moving the battery closer is not the solution, the only correct solution IS the proper wire size for the load and distance.

[crieders]

It is OEM but 25 years ago or so I did have the upgrade wiring harness installed
The battery cables look good insofar as I can visualize them at the battery end end the engine end
It seems to me that the best strategy is to check out all of the connections with the meter,. The spade connection of the ground to the solenoid is not impressive, although I have tried to clean that up and replace it with a new spade  connection. It is extremely hard to reach. I would like to find a better way of connecting all of those wires. I have three series 27 batteries, one of which is dedicated for engine starting via the 1-2-off control at the NAV station. However, no way will she turn over on that one battery currently

[KWKloeber]

Cliff

The 1/4" quick connect "S terminal" is what I call the heat up/expand/loosen/corrode/quick fall-off terminal. It should have NEVER EVER been used on a marine engine.

There's two fixes.
There's a solenoid available that has a threaded-post S terminal.  You need to replace the 1/4" QD terminal with a ring terminal. Otherwise it's a direct replacement - I have 3 in stock; $50 which is just about what the Kubota solenoid costs.

The other way is to cob up a pigtail on the oem solenoid.
https://groups.io/g/Catalina30/wiki/7401

But you need to remove it to do that, so IIWMB I figure why not put in a new solenoid as long as the starter is out?

When you had the replacement harness installed was it just the Catalina Direct piece of junk or was the entire harness replaced from each panel terminal to each engine terminal?

[Ron Hill]

Cliff : You haven't said it, but I recall that you have a M25XP engine ???  I put a bolt extender on my old solenoid so I had more threads - solved that problem.  Go to an auto parts or battery+ store to find an extender.

The reason that we say to check that #4 ground wire on the bell housing is BECAUSE IT IS HARD TO GET TO!!!  That's why it is usually the problem!!  I believe that it is
well OVERDUE its 25 year check!!!  By all means use your multi meter !!

A few thoughts

[KWKloeber]

Cliff

A couple of points I forgot to expand about in my original post about checking V -- I forgot to emphasize that you cannot use a V meter to check for bad connections unless you are applying the load.  A LOW resistance reading across a terminal or cable lug is meaningless.  The meter is measuring resistance (essentially V drop and internally doing the R calculation) using a milliamp current.  When you apply a starting load (that's about 10,0000 times the meter's current,) the resistance (and thus V drop) increases exponentially.  So when measuring V drop across anything like a terminal, you must do it with the load applied that the circuit is going to handle.

I get Stu's point, but it depends on how you use your batteries.  A nearby DEDICATED STARTING battery (which I do not recommend) needs a much lighter gauge cable than starting with your house bank (4 gauge which doesn't meet ABYC standard of 3% V drop in a critical circuit.)  so a nearby starting battery is ok, but then you'll be above the required V drop if you use the house bank in an emergency.  MUCH better (IMO) is to upsize the cables and use the house bank for everything, and keep a nearby EMERGENCY start battery should the house bank be down.  Then you are not fiddling with the selector switch from one to the other (unless you rarely need an emergency start.)

If your symptoms are accurate, there seems to be something else going on -- V drop wouldn't change with a warm engine and have the starter motor crank faster.  She would start easier/quicker being warm, but the starter should turn at the same speed.  And if your 27 battery wont crank, you probably have a bad one.

Using the house two, is it possible that you're (miss)reading a quicker START UP, as being the STARTER is turning faster?   Or is the starter turning the same being cold or warm, but as the battery grinds down when it takes multiple tries, the starter naturally slows down?   You might have a battery cold cranking issue (not initial/charged voltage issue.)  You can test for V in those scenarios to troubleshoot the cause (terminals or batteries) and then proceed to attack it.

How old are they? -- does cranking make any difference using one or two batteries? -- It could be worthwhile to have them tested for cold cranking amps and reserve capacity (or do very complete voltage tests.)     

[mark_53]

...............
Install a dedicated start battery with short cable runs to the starter.

I keep reading this somewhat misleading recommendation.  Moving a battery so it is closer to the starter is just as valid as putting that battery in a central location and sizing the wire properly.  The battery doesn't have to be moved if the wire is sized correctly.  Of course, the further away the battery is the larger the wire.  My point is that moving the battery closer is not the solution, the only correct solution IS the proper wire size for the load and distance.

Stu, all true as long as you don't mind the added cost of the heavier wire. My stingy ways include cost as a consideration to a proper solution.

[Stu Jackson]

...............
Install a dedicated start battery with short cable runs to the starter.

I keep reading this somewhat misleading recommendation.  Moving a battery so it is closer to the starter is just as valid as putting that battery in a central location and sizing the wire properly.  The battery doesn't have to be moved if the wire is sized correctly.  Of course, the further away the battery is the larger the wire.  My point is that moving the battery closer is not the solution, the only correct solution IS the proper wire size for the load and distance.

Stu, all true as long as you don't mind the added cost of the heavier wire. My stingy ways include cost as a consideration to a proper solution.

OK, let's unwrap this myth, too. 

Wire:  for comparison, use #1 wire from the OEM battery box vs. smaller #2 from a battery location under the aft cabin.

WM price for wire:  #1 - $6.99 / foot   #2 - $5.79 / foot

OEM battery box to starter - 10 feet #1 wire  10 * $6.99 = $70
Aft cabin to starter                5 feet #2 wire    5 * $5.79 = $29

Difference in cost of wire is  $70 - $29 = $41

Compare that to the cost of building, painting and glassing in a plywood frame under the aft cabin bunk.

It would most likely be pretty much a wash, when you include the cost of the plywood, the 2x4 supports, the fiberglass and the paint.

************

My point is this:  Those who argue that it is "better" to have the starter/reserve battery closer to the starter itself are engaging in misleading information, because it is the wire size between the battery and the starter that makes it work properly, NOT the distance, and as far as cost is concerned it's pretty much equal to install a larger wire than would be to move the battery with a smaller wire.

[Ron Hill]

Guys : I've posted this a number of times, but when I start the engine I give the starter all of the amps that are available.  I have the main battery selector on ALL/BOTH, the starting battery ON and I've NEVER had a problem!!

A thought