Hard start!!

Topic: Hard start!! (Read 2939 times) previous topic - next topic

Re: Hard start!!

Reply #25 – February 25, 2020, 12:43:29 pm

I seem to remember that a m11 engines fuel system won't send fuel until the oil pressure comes up somewhat. That or it's driven by oil pressure. Something like that. So it takes a few turns to start.

I replaced everything and put a geared starter motor and it starts the same. Valves adjusted.

I will look at the shop manual again and see if I can find the section that talked about this

Re: Hard start!!

Reply #26 – February 25, 2020, 03:03:26 pm

Quote from: craneman – February 25, 2020, 11:00:06 am

Wouldn't a dragging starter show the same excessive voltage drop?

Only to a small degree. Excessive starter draw would bring down the battery as well. Yes, a little more voltage loss through the cable, but excessive starter draw would show as low voltage at the battery.

Yes, hard to separate bad batteries from excessive draw without doing a load test on the batteries.

Re: Hard start!!

Reply #27 – February 25, 2020, 03:06:58 pm

Quote from: craneman – February 25, 2020, 11:00:06 am

Wouldn't a dragging starter show the same excessive voltage drop?

Yes, it might be a LITTLE more voltage drop in the cable.

But excessive starter draw would also lower voltage at the battery-- far more than the drop between cable ends.

Yes, more difficult to diagnose excessive starter draw from bad batteries, as both will show low voltage at the batteries. That is where load testing them becomes a good diagnostic tool, as is checking SG if wet cell batteries.

Re: Hard start!!

Reply #28 – February 25, 2020, 04:12:29 pm

On my M11 there is a short ground cable from the starter negative to the engine. Cleaning it improved starting quite a bit. It is in a particularly dirty place and not readily seen.

Re: Hard start!!

Reply #29 – February 25, 2020, 06:24:49 pm

M11 should be an instant start. Faulty oil pressure sensor should only keep the engine from going above idle but not effecting starting time. ECU will trigger auto shutdown after 30 seconds. Delayed starting is usually because of loss of pressure in the system.

See these videos. Terry takes his time getting to the point but good information:

https://www.youtube.com/watch?v=oCxojfhkYBk

https://www.youtube.com/watch?v=HkUj8-2wZws

Pierce

Re: Hard start!!

Reply #30 – February 25, 2020, 09:10:22 pm

Starter would be my first choice

Re: Hard start!!

Reply #31 – February 25, 2020, 09:50:59 pm

Quote from: dans96u295ft – February 25, 2020, 09:10:22 pm

Starter would be my first choice

May be, but diagnosing by "parts replacement" can get really expensive. Much less expensive to diagnose the root cause.

Re: Hard start!!

Reply #32 – February 25, 2020, 10:40:45 pm

Thank you everyone for taking the time to chime in. Being I had the problem from day one and due to the age of the coach, I have taken Roger's suggestion and have ordered the new Delco 39MT 8200308 starter. I will keep everyone posted!

Re: Hard start!!

Reply #33 – February 25, 2020, 11:01:09 pm

Again how long were you cranking when you found your hot cable. Heat is a direct indication of excessive load/resistance. Put your volt meter in parallel to your cable. Should read zero. Crank engine, should still read zero. If it shows voltage you have corrosion, undersized cables, excessive load, internal resistance. Costs nothing to do. Clean cables. Check voltage across all connections. Should be zero. Cable size should be correct. Verify battery state of charge is above 12.8 volts. If voltage drops excess battery's could be weak. Weak battery will reduce engine start rotation speed. If cranking slow will draw lots of power without reaching starting speed. All good? suspect excessive starter load, change starter. Great batteries will hide failing starter. Oh yes air if fuel will not reach higher needed fuel pressures and will start poorly or not at all. Cables may get hot if start cranking time is exceeded. Will also damage starters. Follow recommendations for starter crank limits and cool down times. Hope I don't sound too matter of fact, it's just what I would do to troubleshoot issue. If your cranking and cranking stop and resolve your problem. I've always preferred the gear reduction replacement starters. Less power draw and I believe faster rotational speed. IMO
Scott

Re: Hard start!!

Reply #34 – February 26, 2020, 12:06:56 am

When I first got my coach I phone Cummins and asked why the M11 turned over a few times before it started not like my old
8.3 which started immediately. They told me that the computer had to read the RPMs before the computer would give the engine
any fuel. I believe he said that the computer wanted to see the engine turning over at a certain RPM

Re: Hard start!!

Reply #35 – February 26, 2020, 09:25:29 am

Quote

When I first got my coach I phone Cummins and asked why the M11 turned over a few times before it started not like my old
8.3 which started immediately.

That's interesting. I've had two M11s both of which did exactly that. My current coach has the 8.3 which, like yours, starts immediately.
jor

Re: Hard start!!

Reply #36 – February 26, 2020, 12:42:25 pm

The geared Delco turns over my m11 at roughly the same speed as the original starter. Meaning my original was not bad I would think. Only way to know is to switch it out it seems after checking cabling and batteries of course.

Re: Hard start!!

Reply #37 – February 26, 2020, 03:55:44 pm

My geared starter always starts with no boost now, but with the gear reduction I can't compare the speed as the sound isn't the same as the old starter. Same batteries and cabling so my old starter was the problem.

Re: Hard start!!

Reply #38 – March 07, 2020, 07:36:05 pm

No one warned me about what a pain in the rear it would be to take out the starter!!! Here are a few pictures. I obviously have have/had a power draw at the starter. Should I now replace the entire power cable or can I replace the eyelet? Trying to trace everything is a total pain!!
I did not have the extension, with me, I needed to remove the 3rd bolt today so I hope to have the old starter out tomorrow. I do believe this is the original starter and I believe the installer used an impact and cross threaded one of the bolts!! I had to use a cheater bar to get the thing out!!

Any tips are greatly appreciated!

Re: Hard start!!

Reply #39 – March 07, 2020, 07:42:59 pm

When working with recalcitrant bolts it doesn't hurt anything to try and work some penetrating oil into the threads as you go along.

You can replace the cable ends if you want to spend the money on the crimping tool for that size cable.

Re: Hard start!!

Reply #40 – March 07, 2020, 08:54:50 pm

Quote from: Old Toolmaker – March 07, 2020, 07:42:59 pm

You can replace the cable ends if you want to spend the money on the crimping tool for that size cable.

Assuming you are able to cut away the insulation and are able to get to clean shiny copper, not copper oxide.

Check the other end as well.

But, smart $$ is to replace it.

Check ground cable as well.

Re: Hard start!!

Reply #41 – March 07, 2020, 09:27:15 pm

You have invested time and money in a new starter. Reusing old cables that are probably worn our or damaged is not a good idea. Alan at Bay Marine Supply will make any size tinned marine grade cable with any lugs you need for a fair price and send them to you pretty quickly. Buying a crimper, lugs and cable to do it yourself works if you are making a lot of cables. Otherwise check with a farm tractor (John Deer or like that) dealer. They almost always can make cables to order. Never cheap.

Re: Hard start!!

Reply #42 – March 07, 2020, 11:27:53 pm

I've always used large welding cables to replace OEM cables that were damaged or too small for the job. Welding cables are more flexible as they need to move with the welding application. They do have many times the copper strands that automotive cables do and may need to be supported if traveling long distances where they hang down. Good practice is to make up an extra ground cable from the battery to the closest frame member. Not a bad idea to make another from the frame to the engine or transmission to insure a good electrical path. Poor grounds are responsible for more than dim headlights.

Copper lugs may be crimped on or soldered. While we have a crimping tool at the shop (hammer type), I usually solder (electrical solder) them on at home with either a propane/mapp gas torch or with welding torch. If you slide shrink tubing down the cable first, you can slide it back over the new lug, heat it and a moisture proof seal is made. Shrink tubing comes in different colors so you can buy red for the positive. Either way works quickly and securely.

When I turn the key, our engine instantly spins like a top. I remember a factory Gates tensioner video where they went to start the big diesel after installing the new tensioner. It slowly hesitated before bringing the starter revs up to speed. No adequate starting system should do this.

Anyone remember the aluminum cables GM used on a couple of years on Corvettes? What a terrible idea.

Pierce

Re: Hard start!!

Reply #43 – March 07, 2020, 11:45:24 pm

Looks as though your cable end was the problem. Starter bin on awhile also. You have the new starter and a good match would be new cables. Your local welding shop may actually be able to crimp properly. Shrink tubing with the inside glue has been a favorite of mine for years and you can get red or black. Keeps the air, moisture, corrosion under control. I do solder some but a strain relief need to be installed to prevent breakage were soldered.
Scott

Re: Hard start!!

Reply #44 – March 08, 2020, 01:20:44 pm

I would recommend using marine cabling. UL1427. Welding may or may not have a pvc compound cover on it. Battery cabling uses rubber.

Why the difference? Rubber melts off and leaves bare metal.

PVC turns to ash and stays on the wire preventing shorting to adjoining cables.

All boats are required to use UL 1427 cabling as far as I am aware.

Just safety,...

Re: Hard start!!

Reply #45 – March 09, 2020, 06:12:13 am

The starter is out! The top bolt ended up being the easiest. I am confident in saying this is the original starter and it seems the installer used an impact with little regard to not cross threading one of the lower bolts!!

I also was able to remove the positive cable. I do think it a welding type cable. It has a mid cable eyelet, should I keep that design or can two cables be used? I will need new terminal connectors (lugs) being both positive and negative bolts sheered when I tried to remove them.

As far as the new starter, is there something I am overlooking when it comes to the end connection inlet? The old starter does not have this and I am not sure if it should be sealed and ignored or if there is something else I need to add.

As always, your time and knowledge is appreciated!
Tom

Re: Hard start!!

Reply #46 – March 09, 2020, 10:35:34 am

Change all of the cables. Clean those mulit point connections .

Re: Hard start!!

Reply #47 – March 09, 2020, 11:23:17 am

So you have/will come across the same problem with your coach in regards to corrosion. You will need to learn how to remove corroded fasteners. Brute force will always break fasteners. Open end wrenches are not to be used till it's loose. Good tools are a must. Learn to slow down and size sockets to fit tight. This means that they may reduce in size corroding. Metric can be used. Okay to tap sockets on with hammer. Six point sockets on six point fasteners. Valve grinding compounds will help lock tool and part together to prevent slipping. Get your propane torch (and using safeguards) heat fasteners and cool with Aero-Kroil or mouse milk. They are both expensive but well worth it. IMO.Reattempt removal and repeat heat cool cycles till it releases. A variety of impact tools will greatly assist. Cordless 1/2 impacters IMO are difficult to regulate. 1/2 air is more user friendly. Pre soak days before with either. The mouse milk is my preferred fluid. Splitting nuts will also sometimes be required. Sometimes attempting to tighten the fastener helps. Also since you live in a very humid area using anti-seize is a must. Get in the habit using on everything in the elements. Striking the head of the fastener with hammer and or punch helps wake it up. Any one thing may work but may require all the above in multiple cycles till it comes loose or fails. Clean removed threads with tap and die set, wirewheel. All good fun. Well maybe not.
Scott

Re: Hard start!!

Reply #48 – March 09, 2020, 11:34:17 am

Read the instructions that came with that starter to locate where the cables are attached. If you don't have them PM me and I will get mine out of the coach and read it to you.

Re: Hard start!!

Reply #49 – March 09, 2020, 12:27:53 pm

Have you cut off the ends and pealed backed the insulation on your cable. If the wire is nice and shiny it's OK to reuse it. Someone
mention using marine cable and one of the advantages the marine cable is usually tinned and that stops the corrosion. As dsd said
anti or never seize is a must.

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