Perkins 6.354: Starts, surges, then dies

Perkins 6.354, non-turbo. 1974 vintage, has run pretty much flawlessly for the couple hundred hours we've put on it since purchase in July 2015. Total hours in excess of 4,000, in case anyone cares.

Recently, it started, ran for a short time (can't tell you how long, as the other engine was running and we were preparing to depart the slip), then died, and wouldn't restart. Changed the Racor (which was quite dirty), and it ran fine for at least 5 - 6 hours over 2 separate trips, a few weeks apart.

A week after the second successful run, we ran about 90 minutes to our favorite little island (in the ICW) where we anchored for some bottom cleaning, and when we tried to start for the return, it wouldn't start. Or maybe it started, then quickly died - I don't recall. (BTW, on a couple of occasions on the trip to the island, the engine surged a few hundred RPM with no obvious explanation.)

Back home (thanks for that second engine!), we inspected the Racor, but it was squeaky clean. So we replaced the on-engine fuel filter. (Can't tell if it was clean or dirty w/o a new hacksaw blade.) After several failed attempts, we finally got the fuel injection unit properly bled, and then it started and ran just fine. And it started and ran several more times over the next few hours, as we tested it from time to time while working on other projects.

NOTE: during several of the failed attempts - before we got it properly bled, I think - it would start, surge a few hundred RPM, then die, and then not restart, until we went through the whole priming and bleeding thing again.

That was a week ago. This morning, I started it. It fired right up, then after about 5 - 8 seconds, surged a few hundred RPM, then died. It's a two-person job to bleed the injector pump, and I was alone, so I haven't been able to do that to see if any bubbles escape - that's my next move, when I can get another set of hands on the boat.

What might be causing the "start, surge, die" cycle? (I know - I really need to try to bleed it again to see if I get air bubbles, which would indicate some kind of leak somewhere - but I'm hoping maybe someone here will recognize that pattern and blurt out an answer.)

Thanks so much!

Check for air getting past the racor o-ring. Just sold my boat and new owner changed filters and had a wrinkle in the o-ring. Would run, not run for various lengths of time until he reseated it.

In addition to the Racor o-ring discussed above, if the Racor was disassembled, look for a gasket that may have been installed upside down. Easy to do as the chamfer LOOKs like it should match the ball. See Compass Marine How To's Photo Galleries at pbase.com_


Also tighten every fitting between the tank and the lift pump and eliminate air leaks.


Finally the on engine lift pump may be bad. They are cheap to replace.


It is almost certainly a fuel system delivery problem that shuts down your Perkins.


David

First find out if you are getting good fuel supply to the filters from the fuel tank.
If you are, then see above posts, if not, the fuel tanks are contaminated, and must be cleaned.
If there is access to the tanks, put a stick in and scrape along the bottom. Does the stick have sludge on it?
This would be a good time to add a "squeeze bulb primer" pump from Seaboard Marine, as you have just had a good lesson on why you need it!

djmarchand said:

In addition to the Racor o-ring discussed above, if the Racor was disassembled, look for a gasket that may have been installed upside down. Easy to do as the chamfer LOOKs like it should match the ball. See Compass Marine How To's Photo Galleries at pbase.com_


Also tighten every fitting between the tank and the lift pump and eliminate air leaks. Finally the on engine lift pump may be bad. They are cheap to replace. It is almost certainly a fuel system delivery problem that shuts down your Perkins.

David

Click to expand...

I, too, think it's a fuel problem (since there's no spark to worry about!). I'll be sure to check the gaskets on the Racor, and every fitting in the system. (BTW, the article on rebuilding the Racor that you linked to is FANTASTIC! I'm ordering the rebuild kits today!)

I disconnected the fuel line where it goes into the fuel injection unit and cranked the engine for 15 seconds. Got at least 8 ounces in that time, and it was a nice pulsing flow, with no air coming out. (8 ounces in 15 seconds is 15 gph, and that's at cranking speed. The engine burns only about 2 gph at economy cruise, so I feel like the on-engine lift pump is doing it's job. Make sense?)

kapnd said:

First find out if you are getting good fuel supply to the filters from the fuel tank.
If you are, then see above posts, if not, the fuel tanks are contaminated, and must be cleaned.
If there is access to the tanks, put a stick in and scrape along the bottom. Does the stick have sludge on it?
This would be a good time to add a "squeeze bulb primer" pump from Seaboard Marine, as you have just had a good lesson on why you need it!

Click to expand...

I looked at it, and I can see HOW to install it, but still not sure why. If I were to squeeze the bulb that's immediately after the fuel filters, I suppose that would show me (in the clear tubing) if I was getting air into the system at the filters, but it doesn't seem like it would help troubleshoot anything else. What am I missing? The article said something like "the advantages of such a system should be obvious" - but they're not, at least not to me.

Squeeze bulb eliminates use of the little lever on the fuel pump. Install it on the same side as your filters then you can bleed it by yourself. I installed mine before the filters which makes filling up the new filters after changing them easy.

Brian,

I don't know if you did it, but when bleeding the injection system, you start at the lift pump, work toward the fuel filter bleed, then to the injection pump, and finally to the injectors. On the injectors most procedures say to bleed the front two. I found that you had to loosen all of them and crank the engine. It's messy, but very effective.

If that doesn't work, given the age and number of hours, the injection pump may have some sealing issues. I just had to rebuild one that had 3600 hours on it. The symptom was the engine would not start when hot and generate required WOT under load. Air can get into the injection pump through bad seals. Bleeding is a temporary fix as it will always come back. Rebuild is about $1700-$1800 depending on how bad.

Tom

I have a T6.354 and had a problem with similar symptoms. At the time I was running on only one of the two tanks. I immediately switched to the other tank and it started right up. There was a sucking sound when I opened the valve to the other tank. I believe the inside of my fuel pickup tube is delaminating and collapsing. Back at the dock I removed the line to the suspect tank and blew air into it and it was easy - so I don't think there's a glob of gunk in the hose. It's on my list of things to replace.

Do you have dual tanks feeding both engines with a cross-over valve, or is each engine plumbed to a single tank?

Gulf Comanche said:

Squeeze bulb eliminates use of the little lever on the fuel pump. Install it on the same side as your filters then you can bleed it by yourself. I installed mine before the filters which makes filling up the new filters after changing them easy.

Click to expand...

Dumb question: if I put the squeeze bulb before the filter, then after a filter change just squeeze the heck out of the bulb for awhile - will it force fuel all the way through the system and back to the tank, along with any air that was introduced during the filter change? Or do I still have to bleed the injector with its two bleed screws?

BrianSmith said:

Dumb question: if I put the squeeze bulb before the filter, then after a filter change just squeeze the heck out of the bulb for awhile - will it force fuel all the way through the system and back to the tank, along with any air that was introduced during the filter change? Or do I still have to bleed the injector with its two bleed screws?

Click to expand...

I'd recommend against putting the bulb in line on a final basis. Go to boatdiesel.com and there you will find a schematic as to how that site recommends it be done. Basically a valved separate line.

Install the primer bulb on the supply side of the filters, and a tee with a valve on the output side. After you change filters, you can open the valve and squeeze the bulb until no more bubbles appear.
The rest of the fuel system should still be charged, with no air present, no further bleeding necessary.
Not sure why, but Perkins always are bastards to bleed once they catch air.
Have you checked to be sure you are getting good flow from the tank?
Blowing air back up the hose doesn't tell you anything, though it might clear it temporarily.

The bleeding process was pretty simple for me - I replaced the final filter at the main pump, loosened the two bleeding screws and then hand tightned them. I can reach the pump lifter lever and the bleed screws at the same time, so I could apply pressure, release screw (release air), tighten screw; repeated about four times until is all clean fuel then tightened the screws. Started right up afterwards. I didn't bleed anything at the injectors, although I didn't have air in those lines either.

I had the same problem on a 4236 and it's definitely air in the system.
Mine was caused by me being overzealous and unwittingly overtightened a brass washer causing a minute crack and quantity of air to slowly build up over time until the engine would finally stop, usually right at the worst possible moment, the time between stops depended on throttle use.
Like you, I also found bleeding was a PIA trying to operate the little fiddly metal lever round the back of hot engine is no fun.
I bought a button hand primer from www.asapsupplies.co.uk and it fits between the fuel line and the filter head. You can just operate it with the heel of your hand while using the spanner with the other.
You can also buy a replacement filter head which changes your filter over to a 'spin on' type and incorporates push button primer, I opted for this version and when you change the fuel filter, simply fill it with fuel when you refit, with a little practice you don't even need to bleed the engine.
If you want to give your boat a prezzie for Christmas look no further.

All great info. I can finally get back to the boat today, and I'm sure all this is going to get me to a solution. Thanks again, TF'ers!!

UPDATE: All I did today was bleed the injection unit (there was definitely a little air in it), then fired it up. Started and ran like a champ. Of course, it did last week, too, so will have to wait for a few days to see if the problem was simply a little air still in the system.

I did check every connection in the fuel system, and all are tight and totally dry, so I'm really hoping it was just some residual air.

Greetings,
Mr. BS. Don't mean to pee in your cornflakes but if a fitting was sucking air it would be dry wouldn't it? NOT saying anything is amiss with the fittings, just making an observation...

RT Firefly said:

Greetings,
Mr. BS. Don't mean to pee in your cornflakes but if a fitting was sucking air it would be dry wouldn't it? NOT saying anything is amiss with the fittings, just making an observation...

Click to expand...

I was thinking about that, but unless it's a perfect one-way leak, where air can be sucked in but not a drop of liquid can seep out, it seems like there would be at least a little moisture.

However, since my last post, I know the problem is not solved, so I don't seem to have any choice but to check every possible point of a leak. (Last night, after sitting many hours, it started, ran 15 seconds, then died, and refused to restart.)

Man, I really hope it's not the injection unit itself...

Greetings,
Mr. BS. Thus far, the overwhelming consensus is you're experiencing a fuel problem. My experience is one of our Lehmans ran for varying periods of time after bleeding then simply died. Long story short, a rubber fuel supply hose between the tank and fuel lift pump (FLP) was collapsing internally (NOT visible from the outside-hose appeared new) and blocking off the fuel causing the FLP to suck air through some? fitting. Fuel hose is cheap.

I have had air leaking into a fuel system without having visible diesel showing on more than one occasion.

I have also had that flex line collapsing on my Lehman that drove me nuts till I found it.

quick cheater for the lift pump instead of laying on the engine (god forbid it's hot):

1. drill a small hole near the end of that lever.
2. run a string/wire/whatever through it
3. attach it to the ceiling(bulkhead?) above the engine so you can just reach across and pull the string (line?) instead of leaning way down to get to the damn lift pump lever.

Gabe n Em said:

quick cheater for the lift pump instead of laying on the engine (god forbid it's hot):

1. drill a small hole near the end of that lever.
2. run a string/wire/whatever through it
3. attach it to the ceiling(bulkhead?) above the engine so you can just reach across and pull the string (line?) instead of leaning way down to get to the damn lift pump lever.

Click to expand...

That's a great idea! My spring has disappeared off the lever though, so I have to push it both ways. But I have an electric fuel pump in line, so once I figured out how to use it.... filter changes (and bleeding) are a breeze. Usually I can do a filter change and not have to bleed the engine. (excepting the secondary on the block)

About your engine. Have you considered installing an aftermarket fuel pump in line, after the primarys, with a tee to a vent line and valve. This way you can suck all the air out of the system after fuel changes, and you have a pressurized fuel system to help the lift pump. The great thing about these is you can see the bubbles escaping when you vent with the fuel pump, and know when the air is out when you get good flow. I keep a couple old water bottles on hand in the filter bucket just for this reason. And I dump the diesel back in the tanks, since it has been through two filters on the way through the pump. These pumps cost about 20 bucks, plus the cost of a couple hose clamps, a tee and a valve on the end of the hose.
Sometimes I wonder if the PO installed it because of fuel lift pump issues or just to make filter changes so easy!?
Here's an example NEJE 12V Electric Diesel Petrol Fuel Pump 2015 – $12.99

All great advice.
Someone said that bleeding Perkins was a barsteward. it needn't be, there's a technical reason, and remedy, for every fault
When bleeding the fuel system, don't forget, ALWAYS open, and bleed, the top bleed screw on the injector pump. then proceed to the injectors.
BUT if you take my advice and fit a replacement modified filter head with longer banjo bolt and change it over to a 'Spin On' type fuel filter head incorporating a button pump, bleeding the engine becomes a thing of the past and a regular subject here on TF..
In the meantime, as and when you check each union/joint, take a flat file, lay it flat, then, then one by one, put each copper washer flat on the file, place your thumb on top of the washer and gently rub it up and down the file until the face of the washer is bright and shiny with no tracks or imperfections on it's face, turn it over and repeat on the other side, reassemble carefully and bleed the system.
Go for the technically easy route and leave the mental masturbation to others with nothing else to do.
Don't misunderstand me I love tinkering around engines, but only to make them more reliable and work for me so I can cruise in comfort.
Good Luck and a speedy solution.

Perkins

I just remembered an old problem we had back in the 70s. It was a 4 cylinder Perkins on a generator. Sometimes would run all day, sometimes would shut down after 10 minutes. If I recall correctly it was the lift pump that had deteriorated in such a way that it would work sporadically. It tested fine when first checked and was discounted as the problem. Later in frustration it was changed and fixed the problem.

Lift pump diaphragms degrade over time and will leak causing this type of problem.
The leaks can be miniscule and very difficult to see even if you take the pump apart. As you have no idea how old they are and they are cheap ..... replace them.

Gabe n Em said:

quick cheater for the lift pump instead of laying on the engine (god forbid it's hot):

1. drill a small hole near the end of that lever.
2. run a string/wire/whatever through it
3. attach it to the ceiling(bulkhead?) above the engine so you can just reach across and pull the string (line?) instead of leaning way down to get to the damn lift pump lever.

Click to expand...

My wife will love this tip - thanks! (She's my primer operator, while I do the bleeding.)

A NEW CLUE!

Back at the boat today, ready to check every connection for a leak. First place to look (since it was recently serviced, which seemed to nearly coincide with the beginning of the problem) was the Racor 500. Took the lid off to check the gasket, and it was NOT full of fuel. I immediately looked at the one on the other engine, and it was full of fuel. As I recall from the previous fuel filter change, it SHOULD be full of fuel. (We've done it only once since we haven't owned the boat that long.)

If there's air in the top inch or two of the Racor, and the Racor is the first thing in the fuel system after the tank (and about 4 feet of heavy gauge flexible fuel line), does it seem like maybe the Racor unit itself is allowing air in? The gasket was perfect, but I changed it anyway, and after bleeding and running some more, checked again, and again there was air in the top inch or so of the Racor. Does this make anyone go "Aha! it has to be <fill in the blank with the answer>!"?

(If not, I'll be investigating every other suggestion made above, and for way less than $100, I'll be replacing the lift pump, just for good measure.)

Brian

Two questions

1. What is the level of the fuel in the tank in relation to the Racor?
2. Are both engines drawing from the same or different tanks?

The fuel lift pump change out will certainly fill in a few blanks.

Greetings,
Mr. BS. Aha! It has to be....EXACTLY the same scenario as I conveyed in post #19. Engine stalls, Racor low on fuel. Replace that 4' of heavy gauge flexible fuel line.

BrianSmith said:

. . . the Racor 500 . .gasket was perfect, but I changed it anyway.

Click to expand...

Ah Ha! So problem appears after filter change eh?

There is an O-ring seal around the shaft of the T-handle. Did you change that too?