Fuel Delivery Issue?

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Fuel Delivery Issue?

December 05, 2012, 11:31:41 am

I was driving back to Austin last weekend from Denton on I35W. As I jumped on the freeway, I seemed to lose power. I was doing about 60 as I was accelerating to merge but then the coach started to lose power and I dropped all the way down to 4th at about 40 - 45 mph (floored). It held there for maybe a minute and then power kicked back in and all was fine the rest of the trip. I immediately started scanning all the gauges and could find nothing wrong. No high temps, oil pressure fine, etc. My first thought was maybe my fuel filter was clogged, but then it wouldn't probably make sense that it performed flawlessly the rest of the 4 hour trip. I'm hoping this was a one time occurrence, but problems don't tend to rear their ugly head only once.

Any thoughts?

Thanks,
Benjie

Re: Fuel Delivery Issue?

Reply #1 – December 05, 2012, 11:34:30 am

when that happened to me, it was clogged filters (algae). started first as hesitation, then power loss. when I got to Cummins Indianapolis and shut it off, we couldn't get it to re-fire to move inside, so they had to do all the work in the parking lot. Fixed, and no problems since. Put in algacide now when it sits. only took a month for the gunk to grow, think I got some diesel with water this summer that made for the algae bllom.

Re: Fuel Delivery Issue?

Reply #2 – December 05, 2012, 11:58:02 am

Probably a bit of air in the injection system or a partial blockage at one of the filters. How much fuel in the tank? Anything unusual other than the momentary loss of power? Would start looking a fuel lines for leaking or seeping. Any visible deterioration on the hoses? Only takes a little air for the engine to drop a cylinder or two. Other possibilities for air would be the fuel pump or even a check valve that momentarily stuck allowing the low pressure fuel supply to the injection pump to drop for a few seconds.

Partial clog of the filter usually shows up first with a loss of power under max acceleration like up a freeway on ramp or up a grade. Not many hills in Texas though.

Once the engine load is reduced, the filter passes enough fuel for the engine to be happy again. Partial blockage is usually worse when the fuel is cooler and the viscosity is higher. On the other hand, I have seen algae settle on the filter bottom after sitting overnight and block the element after running for a while. Could replace the filter if it's been a while. Flashlight and mirror in the tank can check for algae in the bottom.

Like you said, will probably be back again.

Pierce

Re: Fuel Delivery Issue?

Reply #3 – December 05, 2012, 01:07:24 pm

We had that problem off and on for about a year. Found that by turning off the cruise and then back on it would quit doing that. Had the transmission checked, the cruise, changed the fuel filter, kicked the tires, It doesn't do it any more. Somebody said that with the change to low-sulfur fuel the gunk would break loose and go into suspension and clog the filter up. Probably did too many things to really trouble-shoot the problem but the problem was getting down the road so we've just accepted as another RV mystery.

Re: Fuel Delivery Issue?

Reply #4 – December 05, 2012, 01:19:41 pm

How would you propose using a flashlight and mirror to check the bottom of the tank? Purchase a small mirror to stick inside tank to reflect the light down?

Best Regards,
Benjie

Benjie Zeller
(512) 587-4628

Re: Fuel Delivery Issue?

Reply #5 – December 05, 2012, 03:02:32 pm

Benjie,

Depending on where your fuel filler is and if you have a direct view of the bottom of the tank. I use a bright flashlight and a small mechanic's mirror to view the inside/bottom of the tank. The mirror is round and about an inch or so in diameter, mounted on an eight inch rod with an adjustable head. Good for a lot of other hidden items on the coach.

If you don't mind a mess, a hacksaw is a good way of inspecting the inside of the old filter. Algae appears black. Using a diesel additive keeps algae away as well as the injectors clean. Some useless stuff on the market so do some research before buying. As I remember, someone posted a review on the different brand names sold.

Short story: Years ago, I got a load of diesel in the desert for our MBZ 220D that made the engine knock so loud I though it was going to blow up. Drove to a truck stop in Barstow, put a few ounces of additive in the tank and within a minute, the knock was back to the normal diesel clatter. The stuff does work.

For flashlights, I love the CREE T6 available on ebay. They are inexpensive, superbright and fit in your pocket. Perfect for the inside of tanks or general purpose. See varieties at: cree flashlight 1600 in Flashlights | eBay

Variety of mechanic's mirrors at: mechanics mirror | eBay

Pierce

Re: Fuel Delivery Issue?

Reply #6 – December 05, 2012, 05:33:12 pm

Our Cummins C8.3 engine uses a solenoid fuel shut off valve located on curb side of engine. We had similar symptoms when the solenoid opened enough to run engine but not enough to flow enough fuel to drive over 10 MPH or so. Cummins now has a much improves fuel shut off solenoid. We found that we could manually push up solenoid and hold in open position with cable tie to drive and removed cable tie to stop engine. We thought our problem was fuel filter clog, bad fuel, air filter clog, etc.

To check for fuel problems, we use a drill pump to pump out bottom of tank fuel into a glass gallon jar. Let jar sit for a couple of days and if all clear no fuel problems. Water will show on bottom of jar. Algae will show as a layer between water and fuel. We used a copper pipe to reach bottom of fuel tank.

Re: Fuel Delivery Issue?

Reply #7 – December 05, 2012, 07:48:16 pm

Quote from: Benjie Zeller – December 05, 2012, 11:31:41 am

I was driving back to Austin last weekend from Denton on I35W. As I jumped on the freeway, I seemed to lose power. I was doing about 60 as I was accelerating to merge but then the coach started to lose power and I dropped all the way down to 4th at about 40 - 45 mph (floored). It held there for maybe a minute and then power kicked back in and all was fine the rest of the trip.
Benjie

Benji,
If the previous responses regarding fuel filters and auto stop solenoids don't solve your problem, the 8.3's with King Control/Cruise Controls also have an idiosyncrasy in this regard.
Like Larry, I have had this happen multiple times and if stepping on the brakes or turning the cruise control off and then back on again happened to coincide with the problem clearing, I can almost guarantee that the problem is traceable to your King Control unit not seeing ground through your brake bulb filaments. When the KC Unit loses that ground, the fuel rack opening will be limited to roughly a fuel delivery opening equal to 1500 RPM. See the following post for more details:

Cruise Control

It may have some applicability to your occurrence.
Best wishes and Happy Hunting,
Neal

Re: Fuel Delivery Issue?

Reply #8 – December 05, 2012, 07:55:44 pm

All,

Thanks for the info and suggestions. I took a pump and siphon some fuel out of the bottom of the tank. Everything there looked good to me.

As for the filter, when draining, it filled with fuel and the particles in the bottom of the cup. This normal?

I think my first action will be to change the filters and see if that helps. I don't remember if the cruise control was on, but will be sure to pay attention next time.

Regards,
Benjie

Re: Fuel Delivery Issue?

Reply #9 – December 05, 2012, 08:42:03 pm

Benji,

Neal's King Control comment is right on topic and refers to throttle limitations, not cruise control being on.

On most coaches, the throttle pedal is electrically connected to King Control, located in forward curb side of engine, which pulls the throttle cable on the side of the engine. If brake light bulb conditions are not met, King Control will limit RPM. King Control has an electronic board that can be stressed over time.

We stopped at King Control in Minnesota for a checkup and had our board replaced due to an overheated solder joint even though we had no problems.

Re: Fuel Delivery Issue?

Reply #10 – December 05, 2012, 09:17:00 pm

You should not be seeing particles in the fuel you drained from the filter, would appear like you have some algae in the tank. Use an algicide and new fuel filters and also carry 2 extra of each fuel filter so when one clogs up you will have a spare.

Re: Fuel Delivery Issue?

Reply #11 – December 05, 2012, 09:46:23 pm

I had the same problem, seems like it happened more when at full throttle. My culprit was the King Control. I held the bed up while having DW take off at full power and you could see King Control just let go of the tension holding throttle open. Let off fuel petal all the way and then give fuel again and King Control would work.
King Control rebuilt it and all is well now.
Good Luck
Larry Bradley
1998 U270

Re: Fuel Delivery Issue?

Reply #12 – December 05, 2012, 11:27:56 pm

I was really hoping this isn't the case. I wonder why my pump didn't pull anything nasty out of the tank? Maybe the plastic tubing somehow curled back up and was pulling from the good fuel layer. I ordered some of this...

Power Service 09016-09 Bio Kleen Diesel Fuel Biocide - 16 oz. : Amazon.com :

Hope it works!

Quote from: red tractor – December 05, 2012, 09:17:00 pm

You should not be seeing particles in the fuel you drained from the filter, would appear like you have some algae in the tank. Use an algicide and new fuel filters and also carry 2 extra of each fuel filter so when one clogs up you will have a spare.

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Re: Fuel Delivery Issue?

Reply #13 – December 06, 2012, 07:12:15 pm

I think I found my issue...

Re: Fuel Delivery Issue?

Reply #14 – December 06, 2012, 07:14:31 pm

By the way, I looked and my control is Bendix, not King.

Re: Fuel Delivery Issue?

Reply #15 – December 06, 2012, 07:30:51 pm

Quote from: Benjie Zeller – December 06, 2012, 07:12:15 pm

I think I found my issue...

Agreed

Re: Fuel Delivery Issue?

Reply #16 – December 06, 2012, 07:33:05 pm

Benjie,

Go to a marine store such as West Marine and get some BIOCIDE.

Use a KILL dose.

Brett

Re: Fuel Delivery Issue?

Reply #17 – December 06, 2012, 07:39:50 pm

Benjie,

What filter is it, that you cut open and where was it located? Did it get that dirty from bad fuel or from never being changed?

Does Bendix indicate coach has an air-throttle? I heard that some air-throttle coaches still use King for cruise control.

Re: Fuel Delivery Issue?

Reply #18 – December 06, 2012, 07:43:35 pm

Barry,

Correct. A coach can be Air Throttle and King Control cruise.

Actually, that is probably the best combination.

Re: Fuel Delivery Issue?

Reply #19 – December 06, 2012, 07:59:01 pm

My 95 U280 has a Williams air throttle and King Control Cruise. At least if King poops out I still have throttle.
Gary B

Re: Fuel Delivery Issue?

Reply #20 – December 06, 2012, 08:11:49 pm

Our '97 U275 has an air throttle. I think it has the King cruise control. Both work well. The air throttle is a replacement for the original control.

The in house mechanic for previous owner told the story of driving from California to Texas using a broomstick to prop the bed, and a rope tied to the engine control and stretching to the driver position. King Control Throttle and Cruise Control Issues He said they replaced the throttle, but said nothing about replacing the cruise control.

Re: Fuel Delivery Issue?

Reply #21 – December 06, 2012, 08:38:44 pm

OK, now to get rid of the algae. In the old days, we were warned never to dump the fungicide down the drain as one quart would put the town's sewer plant out of business. The later stuff is not as strong but would suggest you contact a boat fueling facility for their recommendation as to the strongest/best brand. I buy a gallon at a time and add the recommended ounces per gallon each time I fuel. You will want to go on the strong side at first. I would have at least one extra set as algae is not the easiest thing to kill. Here is a site with a bit of reading before you start to get rid of the algae: Solving Diesel Fuel Problems

If untreated, it can do damage like the site suggests but you should be able to nip it in the bud. As I said before, I would get that flashlight, mirror and with the coach leaning toward the fuel filler, I would keep checking to make sure there is no water/algae in with the diesel. Looking around on the inside of the tank, it should be spotless aluminum with no visible deposits anywhere. A small hand or electric pump and a length of tubing should be able to suck any water/algae out. Naturally, if the tank is full, it's hard to see the bottom.

Bad engine aside, Olds diesels were delivered with a fuel tank without a drain so every time algae was found, the tank would have to be replaced. I remember watching a Volvo dealership steamcleaning the inside of one of their diesel models fuel tank (VW van diesel engine).

So, call for the latest biocide brand recommendation, use it extra strength at first and then add it EVERY time you fuel. This, along with a visual inspection should keep your engine (and you happy).

Your filters should have protected the injection pump and injectors. There may be a check valve before the filters that could be effected. It is placed around the engine's mechanical fuel pump so a hand or electric pump can prime the system. I has to be there as fuel can't be pushed or pulled through any positive displacement pump. Algae on the check valve seat could cause part of the fuel to try and return and reduce the low pressure fuel supply to the injection pump. The return side of the high pressure injection pump also has a spring loaded check valve to maintain the right amount of pressure in the pump but it should have been protected by your primary and secondary fuel filters.

Good photos. Never hurts to cut your fuel filters apart for a visual when you change filters.

Late engines with common rail injection with very high pressures may use a 2 micron secondary filter instead of a 10 micron so make sure you know the correct filter part number for your engine as the guy behind the parts counter may not be that sharp.

Pierce

Re: Fuel Delivery Issue?

Reply #22 – December 06, 2012, 10:06:45 pm

Quote from: Pierce & Gaylie Stewart – December 06, 2012, 08:38:44 pm

Late engines with common rail injection with very high pressures may use a 2 micron secondary filter instead of a 10 micron so make sure you know the correct filter part number for your engine as the guy behind the parts counter may not be that sharp.

Pierce

Actually, Caterpillar requires a 2 micron final fuel filter for ALL their engines. So, either a 10 or 30 micron primary and 2 secondary.

Re: Fuel Delivery Issue?

Reply #23 – December 07, 2012, 09:52:35 am

Barry,

I cut open both filters, but the one pictured is the large one located in starting battery bay. They were each changed almost exactly one year ago and have about 3000 miles on them.

BZ

Quote from: Barry & Cindy – December 06, 2012, 07:39:50 pm

Benjie,

What filter is it, that you cut open and where was it located? Did it get that dirty from bad fuel or from never being changed?

Does Bendix indicate coach has an air-throttle? I heard that some air-throttle coaches still use King for cruise control.

Re: Fuel Delivery Issue?

Reply #24 – December 07, 2012, 09:54:10 am

Has anyone used this stuff? I purchased this a few days ago and it should show up today.

Power Service 09016-09 Bio Kleen Diesel Fuel Biocide - 16 oz. : Amazon.com :

If not recommended, I'll run over to West Marine.

BZ

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