Hard start!!

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

Hard start!!

February 24, 2020, 07:28:31 am

Good morning,

I purchased my MC just this past fall. I know it had sat for sometime and found a few gremlins on our first trip. I had immediately replaced both the starting batteries and the coach batteries. Even with the new batteries and warm weather the motor turned over slow and was a hard start.
Fast forward to winter and trying to start the coach periodically when the temps would jump up (50's) it will not start. I have recently charged up the batteries again and still just barely turns over. So I went bath to the compartment to check connections and the battery cables were HOT, especially the ground.
Does anyone have any pointers? I have am trying to get the coach ready for a spring break trip with the family.

Any help is greatly appreciated!!

Re: Hard start!!

Reply #1 – February 24, 2020, 07:47:56 am

Some work involved in this. I'm assuming you know how to safety block your coach, you must do this before crawling under. You will most likely have to raise the coach with an auxiliary air source.

Check all battery connections between battery terminals and starter. They must be tight and clean. Before checking terminals at starter, disconnect battery terminals! Also be sure boost switch is off.

If, after these steps, it doesn't spin over good....you probably need a starter. If it does spin over good but doesn't start, crank up your aquahot, switch on engine heat for a couple hours then try to start engine.

Doing keyword searches on this site for "slow crank, starter, battery terminals, start batteries" etc. will provide details.

A good mobile mechanic might be worth considering.

Re: Hard start!!

Reply #2 – February 24, 2020, 07:49:15 am

Issue with slow turning over should be taken care of first, posible starter motor?

Bought my coach 2 years ago. I had same problem with hard start, however none with speed of starter. Spent way too much money with shop diag, over $1,000. First shop replaced lift pump, and solenoid shutoff. Then shop recommended, incorrectly, replacing injection pump. Lucky, I chose to take it off and send it to a known pump shop by me in Portland. They said it was fine.

Then I checked this forum. Found issues with old *fuel lines. Found cracks in lines (air leaks), replaced, issue solved.

Cracks were small, but could be seen near fuel filters, also found fuel smell, fuel dampness, in center conduit in basement bays, and found dampness at curves in hose over fuel tank.

Re: Hard start!!

Reply #3 – February 24, 2020, 09:31:20 am

It might well be starved for fuel. Then check fuel lines. But you say slow turn over. Start with the basics, batteries and cables. Assuming connections at the batteries are good and all the way to the starter then hot cables, connectors or batteries mean a lot of load is getting pulled through them. It is possible that you have a bad battery. They need to be fully charged, sit for a day with no connections and tested with a carbon pile load tester. If any are bad the best plan is to replace all of them. O'Reilly's has great group 31 batteries for about $225 each https://www.oreillyauto.com/detail/b/fleet---heavy-duty-5000/battery-accessories-16452/battery---automotive-16864/battery---best-fit-16245/ec27e4e51018/super-start-fleet-heavy-duty-group-size-31-battery/agm31t/4742641?q=31+agm+battery&pos=0

If they are OK then the starter might be bad or going bad. A new gear reduction starter turns the engine over a bit slower but with more power (torque) from the starter will less battery load. I replace mine last summer. Found a genuine, brand new Delco starter on Ebay shipped for about $300. Genuine Heavy Truck Delco Remy 8200308 Starter 39MT 12V 11T CW See... Delco Remy 39mt Starter 8200308 CW 12v for sale online | eBay

Re: Hard start!!

Reply #4 – February 24, 2020, 09:37:55 am

Totally concur with above trouble shooting ideas. Loose and corroded starter and battery cables are not uncommon. See the thread linked below for a few examples, along with the now famous photo of the John Morales fireworks show.

It Took Me Two Months to Tighten a Nut!

Re: Hard start!!

Reply #5 – February 24, 2020, 09:57:14 am

One thing to consider is what you said about temperature. When temperatures jump up to the 50's, says a lot. The engine block and oil will still be cold. My engine is slower to turn over when it is cold. I run the Aquahot pump for a few hours before I am going to start in cool/cold weather. I find the starting much faster and easier. I check the engine temp gauge for the temps to hit around 70 and it fires right up. It is worth a try.
Glen

Re: Hard start!!

Reply #6 – February 24, 2020, 09:58:24 am

So the heated cable ground or hot is a indication of hi draw, resistance, undersized cables. The 450ISM will draw a lot of power and if you have charged 990 CCA batteries they are maxed out. If there state of charge is low they won't be enough. I would be choosing three good start batteries preferably group 31. A diesel starts by rotational speed and after 5 seconds it will be at near max speed. Has to have fuel to start, already covered
Scott

Re: Hard start!!

Reply #7 – February 24, 2020, 10:11:17 am

As others have said, make sure your cables are shiney clean along with the battery terminals. If some of your terminals are hot after trying to crank it could indicate a poor connection. To check that use volt meter, check between the terminal and wire under a load ( starting) the voltage you read is the loss at that connection. For a better explanation goggle check voltage drop. Be sore and check the ground connection as well.

Re: Hard start!!

Reply #8 – February 24, 2020, 10:17:25 am

Thank you everyone!

I have recently purchased the aqua hot filter and nozzle so I can preheat the motor in the future. I did have this problem when the weather was good last fall.

I will follow the cables to the starter and check connections today. I currently have all batteries disconnected and will be charging the third today. I had not thought about the starter yet but that has been I problem for me on another vehicle. I have had diesel odor in the mid bay and my generator will not stay running so it looks like I better start inspecting fuel lines too.

I do know a place that rebuilds starters so I might consider taking it to them. Any thoughts on that?

Re: Hard start!!

Reply #9 – February 24, 2020, 10:25:44 am

I would first check out your cables. Even with a bad starter they shouldn't get hot. What does your voltage drop to while starting it at the batteries. If the drop is less than at your dash gauge, it's the cables. Running your generator with the boost switch on will help if
your batteries are weak but with hot cables I don't think your batteries are the problem. I have no problem starting my engine when
its freezing.

Re: Hard start!!

Reply #10 – February 24, 2020, 10:29:07 am

This is what your battery connections should look like. Use a file to flatten both sides. I replaced all the washers and nuts with stainless.

When you say your ground cable is hot, is that at the battery or the whole cable? If it's the entire cable, your starter may have gone south. If it's hot just at the battery lugs, then cleaning may do the trick.

With a good starter, batteries, and clean terminals, your engine should spin like a top hot or cold.

Pierce

Re: Hard start!!

Reply #11 – February 24, 2020, 10:33:16 am

Quote from: Farrarkc – February 24, 2020, 10:17:25 am

I do know a place that rebuilds starters so I might consider taking it to them. Any thoughts on that?

"Rebuilt" is only as good as the shop/tech that does the work, and the parts they use in the rebuild process.

In some cases, "rebuilt" is as good as new. Manufacturer rebuilt air dryers, for instance, provide excellent service on our coaches.

In other cases, buying a new item is preferable because you receive the benefit of improved design or technology.

If it was me, and I was going to do the (sweaty & dirty) job of swapping out my starter, I would buy the new one suggested by Roger (above).

But that's just me.

It's your coach, and your decision. DWMYH

Re: Hard start!!

Reply #12 – February 24, 2020, 10:36:06 am

The new starters like Roger posted are gear reduction with much more torque. I had the hard start, but would start, issue until I put one in before the Q. Now it starts quickly.

Re: Hard start!!

Reply #13 – February 24, 2020, 10:54:28 am

Just a note here, check the cabling and connections first including the tie cables from battery to battery. Mine looked good but I had to make 2 new cables due to voltage drop.

Re: Hard start!!

Reply #14 – February 24, 2020, 11:08:16 am

Quote from: craneman – February 24, 2020, 10:36:06 am

The new starters like Roger posted are gear reduction with much more torque. I had the hard start, but would start, issue until I put one in before the Q. Now it starts quickly.

Craneman, which starter did you use and why?

Re: Hard start!!

Reply #15 – February 24, 2020, 11:14:12 am

How long did you attempt to start?
Fuel smell in bay is screaming leak of fuel out or air leaking in.
Gear reduction starters are definitely preferred.
Diesel engine rotational speed represents starting or just turning over the engine. Read somewhere that if stuck and unable to start one can close off the air intake to produce a vacuum in the intake to reduce engine starter load and increase rotational speed then uncover to get that one faster stroke to fire. Sounds interesting, who knows
Scott

Re: Hard start!!

Reply #16 – February 24, 2020, 11:20:17 am

Quote from: Tommy D – February 24, 2020, 11:08:16 am

Craneman, which starter did you use and why?

Delco 39MT 8200308
When I determined my 3 start batteries were putting out more than enough amps to start by themselves and I was having to use the boost switch to not have to grind away at the starter, I bought the gear reduction newer technology starter. Solved the problem. The old starter is much heavier and designed different. I use the same technology on the race car.

What did you do to your coach today IX

Re: Hard start!!

Reply #17 – February 24, 2020, 02:28:18 pm

I had the same problem with my coach. It had two red top batteries less than a year old, but I was having to use the boost switch because the voltage was dropping to 9-10 volts and lugging with out the boost. I added another red top battery to the bank and kept the original leads as is but added another new battery cable straight to the starter and another new cable to the ground (frame). Ever since I have done this set up on my coach it winds up fast and starts fast, no lugging. I am sure there is corrosion on some of the old cable connections and I will have to deal with that in the future. I hope this helps
Just my two cents
Ron

Re: Hard start!!

Reply #18 – February 24, 2020, 05:42:22 pm

Quote

I have had diesel odor in the mid bay

If your Aqua Hot id mid bay it might be responsible for the odor. I had that issue with a weeping diesel fitting and it caused a faint smell of diesel.
jor

Re: Hard start!!

Reply #19 – February 25, 2020, 09:23:29 am

So let me add my similar experience. September 2019 I have a 1999 40ft U320 M11 initial 1st and/or 2nd crank turns slow then pops around faster on 3rd rotation and fires up. MOT stated that is nature of the beast...common problem for 20 years due to high compression motor...? I respectfully requested some further diagnosis. I was informed staring batteries load test great and all connections are clean & tight. I was instructed to always use the boost switch to assist with .starting. 3 1/2 weeks later no start. Fast forward to a small area shop that agreed to assist me. Batteries did again show no issues under load test and this shop also stated to me all cables and connections look great shape. No Selinoid issue but starter appears very tired. I had a new starter installed. However, the mechanic had informed me that the initial draw on starting was in excess of 600 amps and he thought that to be excessive but that would take considerable time/money to figure out why it is such a high draw? I am not sure if my issue is truly a deep underlying problem or nature of the beast. I have religiously turned on boost switch and utilized my AH preheat or bed base switch for engine block heater and have successfully weathered the Wisconsin winter so far moving place to place every 2-3 weeks in some extreme cold temps but without using the boost switch and other engine warming aids the cranking is still the same on 1st & 2nd rotation. Note boost is used regardless of temp. After reading FarrarkC description I can't help but wonder is this a common issue with the 99/2000 U320 or am I/we heading for a future no start issues again??? Have others experienced this same starting issue on similar coaches?

Re: Hard start!!

Reply #20 – February 25, 2020, 10:17:26 am

TRy using jumper cables to add to the ground cabling. Maybe run the cables from the battery pos also to the starter.
When in doubt ,add ground cables.

Re: Hard start!!

Reply #21 – February 25, 2020, 10:26:57 am

ALL diesels are high compression. With the proper starter in good condition, the engine should turn over rapidly even if cold.b You should NEVER have to use the boost switch unless you have a problem somewhere in the starting system.

We have owned our coach for eleven years and never used the boost switch with the exception of the time I melted the start battery terminal because of poor maintenance right after we purchased it.

Our turbo 7.3 Ford/IH and our 300SD have higher compression ratios than your Cummins and never have to utilize a boost switch. The need for the use of a boost switch indicates a problem somewhere in your main starting system.

Cummins has a CCA requirement specification for all their engines. If your battery system meets or exceeds these specifications and you have the proper starter plus the manufacture installed the correct gauge cables for the length of the run when the coach was built, you won't have any problem starting W/O boost.

Ours spins like a top from the instant I hit the starter button. I know Craneman replaced his starter and has no trouble starting his engine.

Pierce

Re: Hard start!!

Reply #22 – February 25, 2020, 10:35:49 am

Quote from: muskyman475 – February 25, 2020, 09:23:29 am

I have a 1999 40ft U320 M11 initial 1st and/or 2nd crank turns slow then pops around faster on 3rd rotation and fires up.

After reading FarrarkC description I can't help but wonder is this a common issue with the 99/2000 U320...

Have others experienced this same starting issue on similar coaches?

If the mechanics that checked out your starting system are correct, then the cables should be OK.

You don't say what size and number of starting batteries on your coach. What do you have?

What is the total (combined) CCA rating of your start battery bank? Chart below (copied from M11 Service Manual) says you need a minimum of 1800 CCA at zero degrees (F). Does your battery bank satisfy this requirement? A little extra capacity never hurts.

If your batteries are up to snuff, and the cables are clean and tight, then that leaves a "weak starter" as the prime suspect.

Roger (Reply #3 above) has a similar size engine. He says a new gear reduction starter made a positive difference on his coach.

Craneman (Reply #16 above) also recommends the gear reduction starter. Something you might consider?

Re: Hard start!!

Reply #23 – February 25, 2020, 10:49:56 am

"Diagnosing" cables is easy. Voltmeter-- one probe at battery, the other at starter or for the negative on chassis ground.

Have someone engage the starter. See how many volts (or hopefully fractions of a volt) drop there is across the cables.

Re: Hard start!!

Reply #24 – February 25, 2020, 11:00:06 am

Quote from: wolfe10 – February 25, 2020, 10:49:56 am

"Diagnosing" cables is easy. Voltmeter-- one probe at battery, the other at starter or for the negative on chassis ground.

Have someone engage the starter. See how many volts (or hopefully fractions of a volt) drop there is across the cables.

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

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