Perkins 4-236 Starting Woes

[Hawkswood]

Hello,

I'm new to the forum and sitting at the bottom end of what feels like it will be a steep (and potentially expensive) learning curve! This forum looks like a great place to start the uphill slog! Please lend a hand if you can!

Here's the synopsis:

1975 Perkins 4-236 diesel, has been running like a champ from Chicago all the way to the Bahamas. Now it won't fire. The fuel injection pump doesn't turn when the starter cranks the engine!

I have dealt with some fuel issues, but I have changed the primary fuel filters as needed.

I had some air that kept creeping into the lines that would cause the engine to quit. I bled the lines on a number of occasions (probably 8 times now). On a few occasions it would start, run, then quit after about 30 seconds. On other occasions she would just keep running for hours.

I searched for fuel leaks that would create a vacuum, but to no avail. I've bled the lines from the tank up (no water or air in the primary filter) and through the fuel injectors...

then things got ummm.... interesting... the engine made a shuddering/stuttering noise when we were running under power, then quit. I went to bleed the lines to find that the fuel injector pump was not delivering fuel to the injectors. I've re-bled everything (including the injector pump and fuel flows clean and bubble-free; I have a hand pump bulb on the fuel line). Now it appears that when I crank the engine to start, the injector pump isn't being turned even thought the crankshaft is rotating.

Busted gears? Do I just open up the engine from the front end and have a look?

Gulp... your thoughts?

Thanks.

[klem]

How do you know that the injection pump isn't spinning? Is it simply that you are not getting any fuel to the injectors? I highly doubt that this is the case although it is possible.

Have you cracked the injection lines at the injectors and do you get solid fuel there? Any air in the injector line makes it very difficult for the injector to pop off since air is compressible so the it won't reach the pop off pressure. Usually, you can crack the line at 2 injectors and once you get solid fuel, if you tighten it back up it should start and pick up the other cylinders soon.

If you truly are not getting fuel out of your injection pump but have fuel going into it, there are a few things to check. First, are you sure that your fuel shutdown is in the correct position? Are you sure that the pump is actually full of fuel? Injection pumps hold a lot of fuel and if you run one dry, it takes a lot of bleeding to get fuel back into it.

I would still suspect an air leak problem. You certainly have an airleak somewhere between the tank and the IP and it is probably before the LP if you suck air after a few minutes.

Good luck.

[Hawkswood]

Thanks for the ultra-quick reply.

I've cracked the lines at the injectors, two at time (I usually bleed them from the top down one by one) and don't get a drop of fuel. It streams out from the bleed screws on the fuel injection pump (when I'm bleeding and pumping from a hand-bulb pump) but never makes it to the injectors when I crank the engine.

I can't even get her to catch spraying WD-40 in the air intake manifold.

I believe that the fuel pump isn't turning when I crank the engine because there is a 'screw' that normally rotates when the engine is running on the outside.

That statement requires a photo due to my lack of knowledge of terminology:

Here's the link

The 'screw' I'm referring to is in the upper right corner of the timing case, exactly opposite the injection pump (which is hidden behind the coolant line that needs attention!).

I've definitely checked the fuel shutdown (at the fuel injector pump and at the cockpit engine controls; throttle is always to full when cranking).

[klem]

You are correct that the shaft should be spinning and if it isn't, that indicates something else is going on. Have you pulled your dipstick yet and seen the condition of your oil? Are there any metal flakes in there?

There are a couple of ways to approach this. You need to determine what is spinning and what isn't. I assume that your crankshaft pulley is still spinning? If so, that would suggest that you need to see whether you have a broken gear or shaft somewhere inside the timing cover. It doesn't look like the cover will be too hard to open but you could do a little bit of diagnostics first if you wanted. You could pull the small 4 bolt cover over the gear for your injection pump on the front of the engine and look in that way. If you do this, you will need to replace the gasket and the seal on it. You could also remove one of your valve covers and see whether the valves are working properly to tell you how the camshaft is doing. You can usually reuse valve cover gaskets.

Unfortunately, your description does not bode well. If something truly catastrophic happened, you should see metal in the oil pan. If one of your shafts broke cleanly, it may not be too bad. This isn't rocket science, if you take a deep breath and think about how all the different parts of the engine are related, you should be able to figure it out.

Good luck.

[Hawkswood]

Thanks for your level-headed response. I'm pretty new at this so I'll take it slow. I have a shop manual on board and it looks like I can get parts shipped to Freeport and pick them up there for a reasonable price if I show my cruising permit. There are worse places to do engine work I suppose.

I'll post updates and photos here as I go and would definitely appreciate outside advice (please keep heckling to a minimum) as things progress. Hopefully we'll leave something useful for the next guy.

I opened up the small cover opposite the IP (injection pump) and found some chipped teeth... and a flake of metal still sitting on top of the teeth... I think it's safe to say I found the main problem, or its rough whereabouts, but I'm left wondering what caused it. I attached a photo.

Any advice on what to watch out for when pulling the timing case cover and on replacing that timing cover gasket would go a long way... I suppose I'll need to buy a part. I'll probably get started taking her apart this evening as she isn't gonna fix herself.

[beneteau-500]

its sheared the drive shaft key, that is why you had to keep bleeding the system as it was running intermittently , remove front cover and you will see the drive gear and pump shaft and more than likely the key ways are not lined up

[Hawkswood]

Thanks. Nice to be honing in. Going to have a look now. Any idea of how complicated the fix is?

[beneteau-500]

it will be if the drive gear has picked up on the shaft if key has sheared just take your time and use a good puller then you will have the prob of resetting the timing but on this model engine is pretty good , also check bottom Idler gear bearing has not gone that can also be the cause of the tops of the gear teeth damage

[Hawkswood]

hmmmmm.... driveshaft pulley has a huge socket size (looks like 1 3/4")... I didn't carry a puller or breaker bar on board. Time to ask the neighbors and see what I can find.

[DeepFrz]

The gears look like they are dry. Is that normal?

[Hawkswood]

In regards to oil I think this is fine. The engine has been sitting for awhile and there is some oil pooled at the bottom of the gear. I always had an oil pressure around 40 psi.

It's really frustrating when the first step is "remove crankshaft pulley bolt" and you don't move past that after a day.

Arrghhh. Any tips from internetland? The bolt has a 1 3/4" head so finding the right socket hasn't happened yet. I know I turn counter-clockwise (opposite normal engine rotation). What's the best way top hold the pulley still while torquing on the bolt??



Thanks.

[Almost Heaven]

I had to change the O.E.M Primary filters on my 4-236 as I could not stop them from sucking air. I used a wix spin on type rather than the twin compression O.E.M When I switched the engine started right away. Problem solved. Also if fuel is coming out the pump bleader without bubbles you air leak is small thus hard to detect. I also installed an electric fuel pump before the manual pump for priming the filter and injection pump. I you go that rout make sure the pump is a flow through type. I installed a switch for on & off.
Fair winds & Our Lord's Blessings
Ed

[Randoneur]

You may need stuff air freighted to you!
Just in case you need them, here is a link to TAD:
TAD for perkins engines, perkins diesel, perkins marine, perkins parts, perkins generators, perkins service

[klem]

In my experience, chipped gears are usually related to something falling into them. This could well be the key mentioned above. it is also worth checking the tightness of all of the timing gear case bolts while you are in there. If something did indeed fall into the gears, take a look around and make sure that it didn't do damage to the timing gear case or anything else.

Have you pulled the entire timing cover? Luckily, it doesn't look that hard to do on your installation.

1 3/4" is a large socket but your local autoparts store should have one. Truck axles and some engine bolts take very large sizes. An air wrench is the preferred method to getting these off but a big breaker bar can be used in conjunction with holding another bolt so that the engine doesn't roll over.

[Hawkswood]

Thanks folks for the links and advice. We're at anchor so I tried to rig something to replace the socket to avoid a trip to Freeport (we're in West End). I suppose in return for your help I should provide some good entertainment and post a photo of my failed attempt... I don't think I broke anything else though so that's the good news. Looks good and windy tomorrow so we'll probably stick around the boat. I'll post that photo in the AM to keep ya'll interested.

Thanks again.