Re: diesel fuel problems

[faithforster26@msn.com]

Hi: Had a incident yesterday in which the engine faltered and then died. Was able to restart but the engine would not respond to increased throttle. Looked at the primary fuel filter next to the fuel pump and there is no evidence of debris. The fuel look light amber in the clear bottom chamber of the filter. We required a tow back to dock.
We are very confused as to what to do next. Called the mechanic and he says to change all the filters which given the circumstances does not make much sense.
I am not convinced about fuel polishing. The boat is a 1988 30ft Catalina. Not sure if the fuel tank has ever been cleaned. We are very careful about fuel and add fuel biocides and stabilizers annually. Also the fuel pump looks pretty rusted on the outside and is probably he original.
We suspect that while out on the water yesterday there were some pretty large swells and it could be that some sludge got stirred up? but why would this not show in the filter?
So we are looking for some next appropriate steps and would appreciate advice from others who have been through the same problem.
Many Thanks, Faith

 

[Stu Jackson]

Have you checked to see if the fuel pickup screen in the tank had been removed?

http://c34.org/bbs/index.php/topic,5078.msg31743.html#msg31743

Easiest thing to do is to blow back through the fuel supply line.

 

[Stu Jackson]

Could also be this:

http://c34.org/bbs/index.php/topic,5078.msg32616.html#msg32616

 

[faithforster26@msn.com]

Hi Stu: not sure what you mean. I do not know how to access the fuel pickup screen. Also have no idea how to blow back through the system. (I am pretty mechanically naïve).
Should I be contacting some fuel cleaning co. or...
Thanks, F

 

[JK_Boston_Catalina310]

I had a friend with an 1988 that had the exact same issues. Here is what was done to fix the problem.

1) Change all the filters. Cheap way to eliminate that as a problem. I am not total convinced that you would see all of the very small debris that could clog the filter. Most Racor pre-filters I have seen are around 2-10 microns in size. A human hair is 17 microns. So you not seeing anything doesn't always mean anything.

2) Rebleed the system. I believe you engine is self bleeding. I would still bleed it and I would crack the bleeding valve and verify flow. We went a step further and cracked each cylinder and that is kind of how we found the problem.

3) If you had good flow while bleeding, try starting the engine. If it runs for an extended period you should be could. Do some tests under load.

4) step 3 didn't happen for my buddy. Actually we couldn't get flow to the cylinders. So we ended up taking the injection pump apart, cleaning everything and then putting it back together. We didn't see anything but something must have been in there because it worked after that.

Now you said your not convinced about fuel polishing. Why? That was another big step. Another friend had previously made his own system consisting of a fuel lift pump and two filters. We had a 25 micron filter on the first and a 2 micron on the second. The hoses just put the filtered fuel back in the tank. I can tell you based on how often flow was choked off in the filters that it was the right move.

Based on a recent experience I had, I also recommend you check all your fuel system connections for loose hose clamps or holes just to be safe.

Good luck and fair winds,

Jesse

 

[JK_Boston_Catalina310]

Hi Stu: not sure what you mean. I do not know how to access the fuel pickup screen. Also have no idea how to blow back through the system. (I am pretty mechanically naïve).
Should I be contacting some fuel cleaning co. or...
Thanks, F

Very easy in your boat. The fuel tank is under the aft berth. There is a large cap on the top that is bolted down. Remove the bolts and you can access the fuel pickup. There is a screen there. We cleaned that on our friends boat when we did the polishing. Definitely a worth while step.

 

[Stu Jackson]

Jesse covered it well, perhaps a bit of overkill, but still good. I haven't polished my fuel, the boat's 27 years old and I've had it for 16 of those years. Some folks swear by it, some think it's an urban myth tied up in snake oil.

88 C30? Most likely an M25 engine, not self bleeding. If it's an M25XP, it may be. Either way, read this: Bleeding 101 http://c34.org/bbs/index.php/topic,6377.0.html

Unless you have injector issues (rather unlikely, but possible) you should not ever crack the injectors on your engine.

Blowing back? Find the inlet to the fuel filter (or pump if you have them plumbed wrong), take it off and BLOW. Hard. Have someone listen at the fuel tank. If you can't blow you have a blockage, most likely that stupid screen. Take the screen completely OFF, do not clean it, do NOT put it back on. Remove it. Completely. Brush teeth. :dance:

Check the filter in the fuel pump yet? Is the fuel pump still working? If it isn't, that's your problem right there, and you may not have to do all the rest of this. If you need a new one, take the old one into a Napa auto store.

Here's a ton of info on your engine: http://www.c34.org/wiki/index.php?title=Diesel_Engine

None of us was born a diesel mechanic, but for most of our purposes, we've all learned over the years. Now you get a chance!

Good luck. BTW, it's not luck at all, it's effort on your part to learn all this stuff. Think about how some of us had to do it before the internet. Darn, we hadda use them old things, I think they were called ...books???...

 

[faithforster26@msn.com]

Thanks Stu: You have supplied me with some very valuable info. Trust me I have read books: I have taken a boat mechanic course and I even participated in changing the fuel and oil filters on the boat last fall. But all remains somewhat mysterious and I think must of us have a healthy fear of screwing up.
I am not sure about the fuel pump but I do believe it is still functional since after being towed to dock, the engine started and appeared to respond normally to increased throttle etc. That is why stirred up debris from the tank seems to be the culprit.
Thanks again for all of your kind help,
Faith

 

[faithforster26@msn.com]

Many Thanks. Certainly seems like a reasonable approach. Screen could definitely be fouled after 28 years of service.
Faith

 

[faithforster26@msn.com]

Thank-you Jesse. Your approach is very methodical and should lead us to a solution.
Faith

 

[faithforster26@msn.com]

Hi Stu: One more question. Rather than polishing fuel or cleaning tanks, would it not make more sense to just change the tank. They are about $400 and I was given a quote of $1000 today for fuel polishing. Makes no sense to me. Talked to Catalina direct and found out about the tank as well as the fuel pump filter which could be the culprit.
Any comments,
Many Thanks, Faith

 

[Stu Jackson]

Hi Stu: One more question. Rather than polishing fuel or cleaning tanks, would it not make more sense to just change the tank.

Yes, Faith, that is what many of our skippers have done. Others have chosen to clean their tanks. Your boat, your choice. $1K for polishing? Urban myth and snake oil --- oops, I said that before.

 

[JK_Boston_Catalina310]

Yes, Faith, that is what many of our skippers have done. Others have chosen to clean their tanks. Your boat, your choice. $1K for polishing? Urban myth and snake oil --- oops, I said that before.

$1000 is crazy when you can make your own setup for $200.

 

[Wayne6034]

Faith,
See my post elsewhere as I had a similar problem recently on my 1997 Hunter 340
Wayne6034
s/v Wind Drift

 

[mortyd]

am i wrong or did you get the engine running? if the engine was in fact running why do you think it's a fuel problem?