Poor Starting after Replacing Fuel Filters

[f433921]

Just completing changing both fuel filters on MH with Cummins ISC 8.3 engine. I have owned the coach for 7 years and have previously replace the filters annually without any issues.

Cycled the on/off the switch several times to initiated the lift pump, engine started, stumbled a couple of times then smoothed out. This is the same results as seen on previous filter changes, so assumed that I was good to go.

Couple days later decided that I would try to see how it started, cranked engine no go, cycled on/off switch several times to initiate lift pump, engine started and smoothed right out.

A week passed before I tried to start it again, It finally did start but more cranking than normal.  Took it for a 25 mile drive, thinking that any air in the system would work its way out after running longer and under load, ran fine no signs of lost performance.  Let the rig set for an hour or so and retried starting, same results as previous, more cranking than normal to start.

Removed filters one at a time and found fuel level in both filters to be down about 1.5" from top of filters and signs of foaming in water/separator filter. Filled both filters filled and reinstalled.  Cycled on/off switch several time and cranked engine and it immediately started, however the engine immediately revved to 2200 RPM and stayed there, I shut engine down.  Restarted engine with same results engine started immediately and accelerated to 2200 RPM, shut it down. When the engine was running at 2200 RPM, I made sure the accelerator pedal was in corrects idle position and it was.

I restarted the engine again and all seems OK, engine started immediately and idled at 600 RPM and ran smooth and accelerator is responsive.  I plan on letting it sit for a few hours to see how it starts. 

Anyone have an exclamation for the fuel filters not being full after a 25 mile trip and for the engine acceleration to 2200 RPM?

I'm no rookie to diesel rigs, been driven and maintaining  them for over 30 years. (VW Rabbit, Dodge Cummins, Chev Duramax, Cummins MH 

 

Jim

 

 

 

 

 

[manholt]

How COLD is it in your area now?  Is your fuel tank full?  You said, water/foaming in fuel water separator.  Did you drain it until just fuel ran out?  As you said, your not new to diesel engines....we all overlook the simple things at times!   You know, 2,500 rpm's at idle, is not normal.  If your dipping below 32 degrees at times during winter, get anti gel and the white Kleen for winter!

[wolfe10]

You have air entering the fuel system.  The question is WHERE?

Yes, since you just changed filters, that is the first suspect.

But, fuel lines can also crack and since they are on the suction side of the lift pump, they typically leak air IN, not fuel OUT.

No idea what could cause the engine to go to governed redline from a start up.  I would sure have the Cummins computer checked for codes (Scan Gauge D, Silverleaf or dealer).

[f433921]

My rig is stored in my shop, and in SW Washington it been in the 50-60 days and only frost a couple of mornings.  The fuel tank in lower than I normally let it get, it's just less than 1/4 tank.

I need to check the routing of the fuel lines, the fuel line colors have always been a mystery to me, but since I have never had any problems with the fuel system I have never dug into it. The water separator filter has yellow fuel lines on both the inlet and the discharge and they look like PEX tubing, the particulate filter fuel lines look like black neoprene. I would have thought the water/separator would be plumbed directly to the particulate filter, but that's not the case because they are side by side and the hosed from both filter disappear in the chassis frame.

Any have  a diagram of the fuel system on a 04 Holiday Rambler Endeavor PDQ?

Thanks,

Jim

[f433921]

I found a diagram of the fuel system for a coach from a previous post on the form.

 

Jim

[kaypsmith]

Is the accelerator, electric, manual, or air operated?

[f433921]

The accelerator is electric,    I have started the rig several times since the 2 events where it accelerated to the 2200 rpm limiter and it hasn't repeated.  I have sent Cummins Support with the information describing the event, hope to get a response will share with response with the form.

I'm going to change the water separator filter tomorrow to see it that is where I'm getting air in the fuel system.  The problem only started when I changed both fuel filters yesterday.

Jim

 

[hermanmullins]

Jim, I am sure you know this but when I change any filter, fuel or oil, I will put a bit of grease on the gasket. This just helps it slide smoothly when tightening.

Two items comes to mind, first maybe the filter wasn't seated properly and caused a leak down and second as we go into winter and with the fluctuations in temperatures there can be a lot of condensation,more with a tank with less then a 1/4 tank of fuel. I always try to top off my tank just before I get home so I have less chance of condensation. 

Just a couple of thoughts from me.

Good luck and let us know how it turns out.

Herman

[manholt]

Jim, Cummings Support is available 24/7/365 by phone...call a Tech today!  Also call REV Group & Tech Dept. for a PDQ on your coach, have your VIN# and Engine # handy!

[kaypsmith]

8 hours ago, F433921 said:

The accelerator is electric

Thanks for the response, I had a similar situation recently on a cold start, mine is also electric, I cleaned the actuator with contact cleaner and have not had a repeat since.

[richard5933]

Since the only real change before/after the problem started was the filter change, that would be the focus of the inspection for me.

Possibly you got a bad filter? Possibly a bad gasket? Wouldn't take much of a manufacturing defect to cause a problem.

Assuming these are screw on filters, it would only take a few minutes to swap them, either for the ones that were just pulled out or a new set. Then you could eliminate the easy items on the list, which are often overlooked.

 

[rsbilledwards]

I learned to never change filters when fuel is low in the tank as there can be prime loss and air sucked into the line as the fuel flows back to the tank. It can get worse as well if the fuel in the lines makes it all the way back to the tank...just ask me how I know. Perhaps a gasket doubled as you reinstalled the filter creating an uneven surface and poor seal.

As for the over run , interesting, someone with more knowledge that those that have answered will have to fill us in

[f433921]

Good Morning, thanks for all  of the response.

I did remove the filters to look at the seals and they looked OK, however I will perform a more thorough inspection today. 

I plan on checking the primary water separator first, since it is on the suction side of the lift pump.

Don't think I will spend much effort until I get to town and get some diesel fuel to at least get it filled to a half of tank. Leaving for Hawaii on Tuesday for short break. 

My last trip was on Washington coast was planning on fill up in Oregon on my next outing, it's  $.30 a gallon cheaper.

I sent a request to Cummins on the over run issue.

 

Jim

,

 

[wolfe10]

Remember, when storing your coach, it is MUCH better to store with a full tank of fuel.  This materially reduces condensation.

And:

If storing #2 diesel (spring, summer, fall fill ups) into below freezing temperatures, add an ANTI-GEL.  PS brand is available at Walmart.

If storing fuel over 2 months in the summer (warm temperatures) or 3 months in the winter, add a BIOCIDE.  Biobar JF is a popular brand.

[f433921]

We just got home last week from the coast and we use the coach at least monthly. I normally fill it up on the return trip home, but our route didn't take us by any high volume fuel stops. My personal daily drivers have been diesel rigs since 1984 (VW Rabbit was the first one, just gave it to my nephew) and the only bad fuel experience came from a mom and pop convenience store.

Thanks for the reminder.

Jim 

[manholt]

Don't know the size of your coach fuel tank, but it's bigger than a rabbit.  Condensation and green growth in your tank, will lead to a more costly bill, than your trip to Hawaii, for what ?  Thirty cents a gallon!!! 

[f433921]

Can't believe that three weeks at 1/4 tanks will cause a problem.

Jim

 

[wolfe10]

No way for us to know. 

First, a "why don't we hear more about this from OTR truckers or other on-highway users"?? OTR trucks they burn their fuel too fast to encounter this issue.

 

Algae/bacteria contamination of diesel fuel depends on several factors:

Presence of water under the diesel (from either condensation or from the station tank/pump). It is at the water/diesel interface that the algae/bacteria flourish.

Presence of algae/bacteria in the fuel you added (as an example most marine diesel comes with an biocide added, as storage is an issue in boats as well. 

Ambient temperature.  Higher temperature, more algae/bacteria growth.

 

As with many things, there are two ways to look at it:

Best practices

What I got away with

Not suggesting which way is the right way for anyone, just that there IS a difference.

[five]

I had a similar issue to the OP's two years ago.  The three fuel filters were fine, but the fuel/water separator had partially lost prime.  It would start, barely, and run rough.

[f433921]

What caused the fuel separator to loose it's prime?

Jim

[rsbilledwards]

Air infiltration with  low volume of fuel in the tank would be a good guess. Not uncommon in Safari coaches but not common either it happens.

[manholt]

I have my Cummings Serviced once a year and make it a point to fill up tank before I deliver coach...150 gal. I have enough Gremlins, don't need to make more!  So, bite the bullet and pay the extra $20-30 more to fill up in WA.  You might save $2,000+!  Don't forget the Biocide!

[jleamont]

What year and make coach is this?

I would start by loosening the filters and inspecting the o-ring on the threads and the outer seal on the filters, while at it make sure you didn't cross thread one of the filters causing the seal not to seat properly, if good move onto the lift pump. Check the lift pump for any signs of wetness, depending on the year of your coach and age of the lift pump it might be experiencing a housing gasket failure causing it to draw air in. All of these should only take a few minutes and cost nothing. 

 

[jleamont]

Regarding diesel fuel issues, you might want to read this article. I got burned on June 2016 from these in my fuel;

https://www.aa.co.nz/cars/motoring-blog/what-is-the-diesel-bug-and-how-can-i-prevent-it/

 

[manholt]

Joe.  That's a great read and important. Unlike you, I would have to spend the $4,000+!  You got rid of yours with $600 in parts...then there is the  Labor cost.  Your post is on page 58, under Engines on Forum! 

F433921, I suggest you read Joe's post.