6bta hard starting

[Don Gardner]

My port engine has always taken longer to start than the starboard engine. It cranks fine but it usually takes two tries for it to start. I have taken the fuel shutoff solenoid apart and cleaned it as well as cut the ground wire from the harness and grounded it to the solenoid mounting bolt. Also I cleaned the connections on the mag switch/soienoid. Not sure where to go from here. anyone have any suggestions?

Topic

[Don Gardner]

The valve adjustment appears to have helped. Some valves were too tight and others too loose.

I want to thank Tony and Rob for sticking with me and solving the problem. As always, great advice. I read through the forum often and always find some relevant information that I can use to make my life easier and keep my boat in good order.

Don

[Tony Athens]

So, what is the final answer? Did the valve adjustment help?

Were the valve on the tight or loose side?

Tony

[Don Gardner]

I dd the valve adjustment last week. Went thru them twice per Tonys instructions. Ran the engines for about ten minutes at 1000 rpms. Two days later I ran thru them again just to be sure. Today I started both engines a few days after the last adjustment. Port engine (the one that was hard starting) started in about 4-5 seconds. Starboard about the same.

[Don Gardner]

Thats it, but I can’t get my hand in over the pump and the fuel lines are in the way to go straight in behind the pump. And the one on the starboard engine cannot even be seen due to access. (I have to use lights and mirrors to change the starboard impeller.) Much easier to use an alternate method.

Don

[Rob Schepis]

Although the grid heaters are supposed to aid in cold starting and reduce cold start white smoke they appear to only do the latter. The pin is a PITA but it should be useable without pulling the pump?

[Don Gardner]

The ambient temp was about 62degrees. I do see a drop on the volt gauges. The heater temps continue to rise as I leave the key on longer but don’t get hot to the touch. Thinking that has nothing do do with hard start because they both act the same and the starboard engine starts almost instantly. The timing pin is behind the raw water pump and I can’t reach it without removing the pump.

Don

[Rob Schepis]

Sounds like they are not working. Never measured with IR gun and not sure how long it would take the exterior castings to raise in temperature. On preheat they draw 200amps on a 12V systems, are you seeing this drop on your volt gauges? What was the ambient temperature? over 95F they do not they do not provide preheat. From 60F to 95F they cycle for 10sec, from 32F to 60F 15sec and 20 sec below 32F.. Yes on the alternate method for doing the valves but why is the timing pin unavailable?

[Don Gardner]

I just checked the grid heaters with an IR gun. In 15 seconds the port heater only increases by 2 degrees and the starboard 3 degrees. The longer I leave the key on the warmer they get. How warm should they get in 15 secs? Also I plan to adjust the valves myself but cannot get to the timing pin. There is an alternate method in my Cummins manual. Do you recommend doing it this way? Example is to bring #3 intake valve to closed position and adjust #5 valves.

[Don Gardner]

I don’t have records of the valves ever being adjusted. As far as fuel, I have only fueled at my marina and they go to great lengths to make sure the fuel is clean. I am going to verify the heater grid is working with an IR gun and then have the valves adjusted by a Cummins tech.

[Tony Athens]

Valve adjustment = YES Easy to do and I’d run thru them twice.. Use a 15/16″ socket and ratchet on the alternator nut to rotate the engine, CW= easiest way .. If some are tight ( usually normal to find that on the 1st adjustment), that could be the issue.

Injectors—– If you need injectors at 900 hours, then you have been feeding them crap fuel/water, etc.. 5000++ hours would be normal for wear & tear.

Tony

[Rob Schepis]

Valves — If never done (or any question as to how well they were done) yes now is the time.

Injectors — 950 hours…Have you ever had bad fuel issues or incidents?

[Don Gardner]

Tony and Rob,
Thanks for the info on the filters. During a chat with my local cummins marine service center I got the same info as well as that a 10 micron primary will not restrict fuel flow. They also said that since I have about 950 hours on both engines I should rebuild the injectors and adjust the valves, as they are due, and will cause hard starting. (Before I tear into the injector pump.)

Thanks again for all your expertise.

Don

[Mike Uliasz]

Got it. Sounds like I need to upgrade my filtering setup. Thanks for the insight in my first semester of diesel 101 and diesel boat ownership.

[Tony Athens]

Filtering Fuel in a Marine Application

It has never made and sense or “cents” to ever to rely on the “last chance filter” in a marine application to protect your engine………….. 30+ years and dealing with 1000’s of marine engines has proven that without any doubt…………IMO, what you feed your engine should already be clean enough without relying on the filter on the engine……Two stages ( 30-sh to 10-ish MIC) of filters before the engine is what all marine engines should use…………………..

Tony

[Mike Uliasz]

Don and Rob, thanks for the replies.

So better off with the 10 micron as the first fuel filter vs the 30 micron and the engine with the 20 micron.

[Rob Schepis]

Yes for the mechanical (non-HPCR) engines the Cummins install docs does specify the 30 micron primary to avoid restriction due to filter clogging. However, to give your last chance a fighting chance the accepted and proven norm is to run a 10 micron primary w/ a vac gauge and change it out in the 6″-10″Hg range.

[Don Gardner]

Mike,
I will be talking with my local Cummins marine shop this week. I will post their answer to that question.

Don

[Mike Uliasz]

Fuel filter

Don,
My boat was setup the same way, just purchased 3 months ago. 10 micron Racor and then the same engine FF5285 filter.

Do you have any additional info to share on how it should be setup?

Mechanic helping me replaced the 10 micron Racor pictured with a 30 micron. Said it would help with fuel flow and the engine fuel filter would do the rest. Thanks

[Don Gardner]

Rob,
So it appears the primary filter on my boat is a 10 micron and the on engine filter is a 20 micron. These are the filter numbers that were on it when I bought the boat in 2017. This appears to be the opposite of the way it should be. However the on engine filter seems to be the recommended filter from the info I can find.
Don

[Rob Schepis]

Not directly familiar with the FS19934. Here’s the spec sheet:
https://catalog.cumminsfiltration.com/catalog/partsearch.do?&reqCmd=PartInformation&partNumber=FS19934&PartType=Fuel/Water%20Separator&Part=-&criteria=part&_locale=en

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