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Topic: Starting issues… (Read 685 times) previous topic - next topic

Starting issues…

99 u320.
Three new interstate batteries (9/23)
Newer starter (4/22)
Batteries starting at 12.8v
Turn key to acc, drops to 12.4.
Voltage dropping to around 10.7v while cranking.
Cranks slow (or so I feel)

Replaced battery ties to military style battery terminals.
Replaced the terminal blocks near the batteries and cleaned lugs added some dielectric. Cleaned up the connections on the starter relay under the bed and the 90a connections under the relay.

Not sure what else to check besides maybe replacing all of the wiring.

Any suggestions?

Video of cranking. https://youtube.com/shorts/hkh9k3staj0?si=rOZjKXQaOrnQyLL1

Re: Starting issues…

Reply #1 –
Sounds just like mine. I think its turning over just fine.

Re: Starting issues…

Reply #2 –
Have to make some assumptions

Your new batteries are in fact cranking batteries and not batteries for deep cycle.
Outside temp is in the relatively normal range, not in the thirties

If the voltage drop you see is at the dash meter, that may be normal.  Just all the wires to get to the meter.
The sound of cranking really isn't that bad with start under 10 seconds.
Did you try boost switch?  With all that solar you probably have a big house battery bank to assist.

Jerre

Re: Starting issues…

Reply #3 –
That sounds about like ours, when it is the first start of the day without the boost on.  I try to always use the boost in cold weather or for the first start.

I cannot speak to the voltage drop - just don't know.  Other than to say it is a big honkin' engine.

My understanding is that the computer must see oil pressure before it will allow a start, so the 3 to 7 seconds of cranking is normal.

Re: Starting issues…

Reply #4 –
Thanks guys. My limited audible knowledge has me concerned. I've heard many other diesel engine and none seem to turn this slow... the 8.3s seem to turn over pretty quick.  I understand it needs time to build fuel/oil pressure prior to start.

This was without the boost on and at ambient temps around 70 in Vegas. Boost seems to help it turn a lot better (even with my tiny 60ah 12v battery). If it sounds normal to most, I won't worry too much.

Re: Starting issues…

Reply #5 –
Wow, I hope there is a typo there.
3500w solar with 60 AH house just hard to believe.  What are your house batteries?  Maybe 600AH?  Lithium's?
I had 1100 w solar with 1600 AH lithium, never a problem.  Now have 1600 AH lithium but no solar yet.

Jerre

Re: Starting issues…

Reply #6 –
Is your new starter a reduction gear starter

Re: Starting issues…

Reply #7 –
Zach,

Our coach has a direct drive starter and it spins over our engine a lot quicker than your little clip. At those temps the starter should spin that engine like a latch on an outhouse door. It is like you are not getting fuel as if you could have a leak in a fuel supply line. You didn't state (or I didn't understand) but did you clean all the ground connections on the frame and engine?

Mike

Re: Starting issues…

Reply #8 –
Seems to take just a little bit longer than it should to fire.  Mine does the same thing if it sits for a while.  I suspect you still have the OEM Winn fuel pre-filter unit and you may have a small leak there.  That is the cause of my hard start issues when they occur. 

Here are a couple threads to read through:

WINN 300200 pre-filter

Post #8 here shows the Winn unit these came with from the factory.  The plastic housings are known to warp and cause air to be sucked into the fuel system, and there are also internal O-rings in the filter housings that can cause leaks as well. 

2001 U320 Fuel Automatic air purge Racor

Re: Starting issues…

Reply #9 –
You may have poor ground cables on the start battery or engine itself,. If the Boost batts pick up the RPM a lot . Clean all of the grounds.
  Add a BA ground cable  direct to the engine from the batts . 

Re: Starting issues…

Reply #10 –
Quote from: DaBus –
Wow, I hope there is a typo there.
3500w solar with 60 AH house just hard to believe.  What are your house batteries?  Maybe 600AH?  Lithium's?
I had 1100 w solar with 1600 AH lithium, never a problem.  Now have 1600 AH lithium but no solar yet.

Jerre

Not running a 12v system. Just put in a separate small 12v battery to start the genny and give a bit of a boost to the engine.

I plan on running an additional ground wire to the engine, possibly, tomorrow. Not sure what size would be appropriate, but I have several different sizes.

Re: Starting issues…

Reply #11 –
Quote from: Protech Racing –
You may have poor ground cables on the start battery or engine itself,. If the Boost batts pick up the RPM a lot . Clean all of the grounds.
  Add a BA ground cable  direct to the engine from the batts . 
BA ground cable????

Re: Starting issues…

Reply #12 –
Our 8.3 sounded similar.... Before i added the 3rd battery to bring it up to 2550 cranking amps. Now it starts immediately, doesn't even give itself a chance to build oil pressure. 
  Before it was almost a fingers crossed thing if I wasn't using the boost.

Re: Starting issues…

Reply #14 –
My U320 has basically the same engine as you.
I also just replaced my 3 start batteries this summer with the same battery's you have.
My engine cranked over much faster than yours even before I replaced the 10 year old start batteries.
I run each of my start batteries to a bus bar for both + & - terminals and keep all the runs an equal length. I also made new cables from 4/0 cable and military style battery clamps.
I would inspect all the cables +&- and make sure you have a good chassis ground.
How did it crank over before you replaced the batteries?
Your engine sounds like its only getting juice from 1or 2 batteries, not all 3.
Have you checked the starter for excessive draw? How does the starter feel after you have cranked it, is it overly hot?
Buying auto parts now a days is a crap shoot, you could have a new defective battery.
Check each battery with a load. or turn on your headlights and see if they dim appreciatively when you crank the engine.
Are any accessory's making noise, like a bad bearing (A/C compressor, Alternator, engine air compressor)?
Does the engine turn over faster when you add the house battery's with the boost switch?
What weight engine oil do you run? I run Rotela T6 synthetic. My engine spins good even in the Chicago winters and I know the oil will get to the vital engine parts faster.

Re: Starting issues…

Reply #16 –
Ended up adding a 1/0 cable from negative battery to engine ground near the starter. Seems to have helped. Didn't struggle as much as before.

Here is an updated clip of a cold start with no boost. Cold meaning ambient temp of around 75F.

https://youtube.com/shorts/ndEdkdUVzI4?si=-LSYzMMRcp_elE1e

Re: Starting issues…

Reply #17 –
There is a definite improvement. When I had the Monaco with the mechanical 8.3 Cummins it would
start immediately, and it took me awhile to get used to the computerized engine that the engine had
to turn over at least twice before it would start. I find that the M11 starts way better then the 8.3 below
freezing.