Surging Engine
Date: July 3, 2000
From: Sam Woolsey SamWoolsey@aol.com
Forum,
About an hour into a planned 5 day trip up the Mississippi River from St. Louis, the Perkins 4.108 on our Endeavour 40 started surging. Initially, it would surge from about 2500-2700 then back down to 2400. As we continued the RPM would increase and remain at the higher RPM. At this point, the RPM could be reduced using the throttle control.
Eventually, the RPM surged and rapidly increased to MAX at about 3400 and the RPM could not be reduced by means of the throttle control.
What is the cause of this phenomenon and what do I do to correct it?
I read somewhere on the net that possible causes for surging Perkins engines (2200-2500RPM) are dirty fuel and air leaks. Nothing was said about loss of throttle control at MAX RPM.
I plan to:
1) Add biocide to fuel tank.
2) Clean and Replace Racor and engine Fuel Filters.
3) Check & tighten all fuel lines.
What else do I need to check and do?
Date: July 5, 2000
From: Bill Lezotte wlezotte@indiana.edu
Be sure to check your lube-oil level. Some diesels will develop bad rings or cylinder sleeves and burn the lube-oil. It could also be a faulty governor or fuel injection pump. What color is the exhaust? If either the rings or injection pump are bad the exhaust color will change. But the governor has a spring that could break and duplicate your problems with out changing the exhaust color. There should be an inspection plate for the governor and the governor adjustment. You could see part of the spring
there.
Diesel rule #1 if it isn't using lube oil then it's the fuel system. Start by replacing filters and fuel lines. Even a pin hole / crack in a fuel line can cause freakish behavior. '80 E32 (recently rebuilt engine)
Date: July 5, 2000
From: Clint Spooner SCS@nixonvan.com
I have noticed surging in the Perkins 4-108 powering my E40 when there is an air leak or a water clogged fuel filter. In both instances the problem was severe enough to stop the engine. I would guess that if the air leakage were no sufficient to stop the engine it could result in continued surging. However, I would guess that a partial blockage of the fuel filter would have the same effect as a reduction in throttle, unless the surging is due to the water injection (you might check the fuel filter to see if only a small amount of water is being picked up). Good Luck.
Date: July 5, 2000
From: John Bartoszek jbartosz@symbol.com
Sam,
I had a similar occurance this weekend. My engine started surging just before it died. Surged for about 2-3 mins. Turns out I had inadvertently left the fuel shut-off in the closed position. So my cause was due to lack of fuel but the symptoms were the same. I would suspect your engine was starving for fuel due to the reasons you suggested, i.e., dirty fuel filter causing fuel starvartion.
By the way, I will be very careful in the future to not run te lines dry. It took my over a half hour to get the fuel flowing again and bleed the air out of the system. Good luck.
Date: July 5, 2000
From: Phil Johnson JohnsonPN@nswccd.navy.mil
How timely! I spent the 4th of July in my engineroom working the same problem.
I'm having the same problem you described. It started about 5 years ago, first only at the end of long hot days on the waterway. It got progressively worse until it would surge every two min. or so even at idle. This past winter I had the main injector pump overhauled ($800) thinking it would cure that problem as well as zero the maintenance meter on it (5000 hrs.). Also new Racor filter, new on engine filter, new hoses, new lift pump....
Well that did not cure the problem. I have had several friendly discussions with the injector shop. The governor is the hydraulic version which is more prone to this type of problem. The injector shops conclusion was it must be air drawn in to the system. In trouble-shooting I have connected a temporary potable fuel tank directly to the injector pump and the problem went away! Tonight I'm going through the on engine fuel system checking the rubber seals in the metal lines from the filter to the pump.
I will have more tomorrow.
Date: July 5, 2000
From: Sam Woolsey SamWoolsey@aol.com
Paul,
I did the things I indicated in my posting this subject. Things seem to be back to normal with proper idle speed and no surging. Maybe I am home free. Thanks for posting my problem,
Date: July 5, 2000
From: Sam Woolsey SamWoolsey@aol.com
Paul,
I want to thank you and all of the members of the Forum for their responses. It is wonderful to have such a body of hard-won experience just a computer/telephone line away.
A little more about the symptoms. Just prior to the start of the trip, I noticed that the idle RPM had crept up to about 1000 from its normal 7-800. Just prior to the trip, I drained the sediment in the Racor bowl and it appeared normal with just a little gook in it.
Initially, I attributed the surges to failing 2-1/2 year old 2 year warranty batteries causing the 100 Amp alternator to work overtime. Then the surges began to occurr more frequently until the engine became uncontrollable by throttle.
To remedy the problem, I followed the plan I previously outlined - 1.) Added biocide to fuel tank. 2.) Cleaned and Replaced Racor and engine Fuel Filters. 3.) Check & tighten all fuel lines. and Bled the fuel System.
After finally getting the engine to start with my failing 2-1/2 year old 2 year warranty batteries, I ran the boat on the river about 2 hours yesterday and didn't have any problems. The idle is back where it should be. The fuel in the bowl is sparkling. I hope the problem is solved.
Thanks again.
Date: July 5, 2000
From: Luther Carrier Lelair@aol.com
SEE THE FOLLOWING ARTICLE ON 'RUNAWAY DIESELS'
--------------------------------------------------------------------------------
I like synthetic oil for marine engines ON PAPER, and I use it. Here's the reverse perspective on Marty's pensive comments:
(1) When I find engine fluid leaks, I fix the leaks. Going offshore requires everything to work it's best. Also I like avoiding any environmental and major cleaing problems.
(2) Manufacturers specifications are based on "minimal" requirements and specifications. Synthetic oil is above these specifications at the top of the scale.
(3) I've never heard of synthetic oil causing "leaching" of oil past rings and valve guides. The most common reason I know of for "runaway" diesel engines is due to excessive wear at the valve guides. This can be caused by not changing the oil and filters at regular intervals. There are other reasons but not as common.
(4) I don't know of any manufacturer who wouldn't honor engine warranties if you "upgraded" to synthetic oil and kept an engine log (with receipts). I would be very interested if any manuf. had not honored a claim saying that it was the synth. fault. Besides, a mechanical forensic "autopsy" would find the real truth in engine failure. But those are hard to find offshore.
That's why I recommend synthetics like Mobil-1. And personally, I add another product called Militec-1. My analasies come back perfect with extremely minute copper and carbon content.
But I'd be careful on adding something as slick as I use on a very worn engine as I've seen main bearings "spin".
Taking the oil pan off and looking at the copper in the bottom of the pan and using a Plasti-Gauge on the main bearings may help you determine if you need an overhaul. (don't forget to check end play while your're there). But sometimes just looking at the engine and hearing it run will do the same thing. Good luck one and all... OceanBien
Date: July 6, 2000
From: Phil Johnson JohnsonPN@nswccd.navy.mil
Things I have learned about the CAV hydraulic injector governor on Perkins 4-108 in the last day or so.
- It is possible to run the engine with a clean portable fuel tank, squeeze bulb and fuel line directly to the distributor injector pump. 5 gallons will last about 20-30 min. with the return going back to a half full main storage tank via the normal piping system. Flow through lift pump is maintained via the on engine fuel filter continuous vent.
- The lower the pressure supplied to the injector governor the higher the idle and operating RPM ( if rig above is used idle is 1500, + no lift pump pressure + ).
- By squeezing the prime bulb on test rig (i.e. increasing supply pressure) the RPM can be lowered to normal momentarily.
- Obstructions (blockage) in return line from injector pump causes engine to slow when throttle is advanced to full and speed up momentarily when returning throttle back to idle.
- A small bubble of air is observed just after, but in sync with the periodic engine surge from the unused on-engine filter plug when connected to a clear 8 oz. fuel filled and receiver.
- Temporary clear fuel lines to and from engine aid in looking for air.
The pressure gages go on tonight, as I'm not sure where air can be drawn in if (big if) the system is under pressure after the lift pump.
After replacing rubber goods in suction lines surge is only slightly better.
Any other thoughts / suggestions are appreciated.
Date: July 6, 2000
From: A.C. Whitlow sailcat@erols.com
I'm sure this isn't the problem, but you should make sure the engine isn't over filled with oil. As I recall, a worn diesel and too much oil can be a fatal combo for the engine. The oil slips past the rings and the engine begins to use it as fuel, running faster, drawing up more oil... you get the picture. Might be worth checking.
Date: July 6, 2000
From: Tom Gilbert TGil95746@aol.com
Good Grief !!!!! Check your engine oil !!!!!!! You may have fuel in it, which may lead to uncontrolled over speed and ultimate engine failure. Of course, it could be something simle, too.........
Date: July 7, 2000
From: Fred Altmann fred.altmann@attglobal.net
Sam,
Don't forget the simple thing: Check the throttle cable. Is it tight at the beginning and at the engine side? Best regards.
Date: July 9, 2000
From: Bill and Shawna Bonewitz bonnie_kailum@yahoo.com
Sam,
We are a 40ft. Endeavour, s/v Bonnie Kailum, and my husband, Bill, said to possibly check all the injector connections and fuel line connections and if after that you could possibly have a pin-hole in one of the fuel lines supplying engine or even a crack in your Racor setteling bowl. Sounds like you might possibly getting an air leak in the fuel supply system. Good luck.
Date: July 9, 2000
From: Josh Wallach jwallach@flash.net
The usual cause is a clogged or clogging Racor. As a final measure, you may have to have your tank cleaned and fuel polished if the bacteria has been growing for some time....
Date: July 9, 2000
From: Josh Wallach jwallach@flash.net
The usual cause is a clogged or clogging Racor. As a final measure, you may have to have your tank cleaned and fuel polished if the bacteria has been growing for some time....
Date: July 11, 2000
From: Sam Woolsey SamWoolsey@Earthlink.Net
The solution was as I outlined in my plan. It seems to have solved the problem.
Date: July 11, 2000
From: Joe Alvarez JAl1748@aol.com
I had a similar problem on my E-40 and the Perkins4-108, however id did not get to the point where I could not reduce the RPMs, I did have some dirty fuel and the Racors were clogged, so I replaced the fuel and had the tank cleaned, then shocked the new fuel, replaced the racors, and as a further caution replaced the tachometer, as I feel that the original tach from 1984 was not giving a true reading.
Date: September 8, 2000
From: Carl Hibbard Chgypsy@aol.com
I read somewhere on the net that possible causes for surging Perkins engines(2200-2500RPM ) are dirty fuel and air leaks. Nothing was said about loss of throttle control at MAX RPM.
What else do I need to check and do?
Sam, You probably have it fixed but.....
If it was just the surging I would say a possible problem with your mechanical pump, or the injector pump itself. But with the run away it has to be a fuel source. One that comes to mind would be to much oil in the crankcase or your air cleaner setup is picking up engine oil from under the valve cover.
Date: November 8, 2001
From: Phil Johnson flippery@bellsouth.net
The problem you address reguarding the engine running up the back is a symtom of fuel starvation.(yes rpm goes up if it has lower suction pressure) You may wish to replace your fuel filters and check again. This only applies to pressure operated CAV governors. I have experienced this on my 4-108 before.
