4-236 hard to start Lift pump perhaps?

Author Message   Terrill W. Boykin New member Username: seatime Post Number: 1 Registered: 01-2008 Posted on Wednesday, January 16, 2008 - 04:05 pm:    Engine died the other week. I have two Racors and a primary on the engine. So I started with changing all the filters, starting with the primary. Engine came with the boat with less than 100 hours on it and I have put about 50 hours on it. Two racors are inline and the first in line was rather dirty and swolen. Prior owner told me he had changed the filters, but I don't think so. Ran one tank rather low and that could have been the problem. Well after changing the filters, the engine started right up. But now 5 weeks later after it sat up for that time it will not start. Checked the filters, they are fine. Tried to bleed the engine, got fuel to each injector using the lift pump lever and fuel ran out but did not sputter or gush out as I seem to recall it should. I have ordered a lift pump just in case and will add it this weekend and perhaps this will end the problem. Tanks are above the filters and fuel is gravity fed. Any ideas? Does anyone else suspect a lift pump problem. Would they break at such low hours (remember the boat sat up for a long time before I bought it and only had 100 hours put on it in 5 years when I purchased it. thanks terry   Dwight Brooker Member Username: sailmaster Post Number: 70 Registered: 05-2006 Posted on Thursday, January 17, 2008 - 07:30 am:    Normally when you have 2 primary filters (racors) one is used as a stand-bye while the other is on line. (Remember the racors (water separators) are the first fuel filters inline from the tank and are called the primary filters. The secondary is usually on the engine and is 2 microns.) If one of the racors gets plugged while motoring the other can be switched over and the dirty one replaced, again while motoring. What micron sizes are the racors? They should be 30 microns. Did you change the secondary filter? You cannot prime the injectors with the lift pump. You prime and bleed the "fuel injector pump" with the lift pump and crank the engine over to bleed the injectors after that. To bleed the fuel injector pump on the 4-236 you first open the lower bleed screw and pump until no air comes out, then close it and open the top bleed screw and do the same. Then you open the fittings on the injectors and crank the engine until fuel squirts out a little, close them and start the engine. If it does not start repeat the process. If all is well from the racor to the injectors then you may have plugged or holed fuel line. If the fuel lines are fine then you may have algae in the fuel tanks plugging the pick up tube. If the boat sat with old fuel in the tanks the algae may be the problem. If all is well with the fuel system and the tanks and you have replaced the lift pump then you will most likely need to have the injector pump rebuilt. Although the engine has low hours the injector pump can be damaged from water in the fuel and sitting idol. Before replacing the lift pump systematical go through all of the fuel system from the tank to the injector pump. Good luck.   sean saint New member Username: saint Post Number: 1 Registered: 01-2008 Posted on Wednesday, January 23, 2008 - 10:52 pm:    Hello, I'm a newcomer in disel engines and I have the same problem with my 2.436 ,could not start at all we found two problems , water in the tank and the electrical pump was not working. so the new pump will be replaced ,and take care of the water in the tank.   Dwight Brooker Member Username: sailmaster Post Number: 71 Registered: 05-2006 Posted on Thursday, January 24, 2008 - 05:45 am:    I am sure that you meant 4.236. That engine originally came with a mechanical lift pump which is still available. I would replace the electric pump with the mechanical pump as the old KISS analogy infers, you do not want systems to be more complicated that need be. The mechanical pump will out last the electric pump by far and you do not have to deal with another electrical circuit. You will want to run fresh clean fuel through the engine ASAP. The water will damage the injector pump and injectors.   Terrill W. Boykin New member Username: seatime Post Number: 2 Registered: 01-2008 Posted on Thursday, January 24, 2008 - 11:11 am:    Well bought two lift pumps one to keep as back up so the electric is out for the time being. Now that I have the lift pump I can say they must have redesigned the pump a bit. Everything looks the same, but the pump lever is more substantial and there is much more resistence in the new pumps at least it seems so though I have yet to install it. I hope to go out this weekend and install it. I do have one oberservation. There seems to be some disagreement about the racor system. The boat came the way it is with two inline racors and another filter on the engine. Having changed all of them and found no dirt or anything in the one filter on the engine and no dirt in the lift pump screen (which is original) and a rather dirty racore (the first in the line of filters) I would guess it is doing its' job. I will have to check the filter specs however. On my old boat I installed the same system after a recommendation by a guy who use to work on train engines or a train company (CSX or one of them) He suggested inline filters. Yet I have read others that have suggested that inline is not the way to go and that one should be used with a switch to allow you to switch to a clean filter and thus not have the engine die. So I spoke with a racor tech who suggested that inline was the way to go as you have a better chance of not getting stuff in your injectors, though your engine may die if you fail to check the filters. Yet I don't think there was more than 100 hours on the filter that was foul and dirty (likely gunk of some sort from the bottom of one tank that I ran rather low on my recent trip, so I am going to check that tank and have it cleaned if there is a problem) but this leaves me with the same issue. Don't frankly like having the engine die like that, don't want to have to pull the fiter element every month just to see how it is doing (though that seems the best way right now to assure no engine kills and certainly not while entering the dock with a 33,000 boat!) So I guess I don't know the answer.   sean saint New member Username: saint Post Number: 2 Registered: 01-2008 Posted on Thursday, January 24, 2008 - 12:21 pm:    Yes.thanks for the correction I have the 4.236 also I have a electric pump just before the primary racor filter ,and is not working I'm trying to replace it and the parts sales guy told me that that engine did not have a electric pump ,so do I need that pump or not ? or he doesn't know more than I do ?   Dwight Brooker Member Username: sailmaster Post Number: 72 Registered: 05-2006 Posted on Saturday, January 26, 2008 - 06:28 am:    Terrill, once you have your tanks clean and treat the fuel with algae inhibitor you should not have problems with clogged filters. Never run the tank down, always leave at least 25% reserve. This will insure that you have fuel for emergencies and you will not pump crap through your filters. Remember the rougher the sea state the more the crap will loosen and be filtered. Sean, the parts guy is right; the engine did not come with an electric pump. I have seen electric pumps used when the fuel tank is a long distance to the engine, but it was used along with the mechanical pump. This is probably not the case as I have only seen this once out of hundreds of boats that I have worked on. The electric pump should not pump into the racor; it should suck from the racors. Your fuel system should have negative pressure until after the lift pump (mechanical). After the lift pump it will be positive. I would suggest buying the stock lift pump and trashing the electric pump.   Terrill W. Boykin New member Username: seatime Post Number: 3 Registered: 01-2008 Posted on Monday, January 28, 2008 - 03:22 pm:    thanks, got the lift pump on and engine started. I tested with my hands the old and new pumps side by side, and though I replaced it anyway, frankly I think there was some air I could not get out of the system for some reason. Both pumps sucked air in and our and I put fingers on each end of both and pumped and it sucked in on the old one as is should and responded much like the new one did. Just so you know even with the new life pump, I never got a squirt out of the heads as I used to get on my old volvo. I did get more bubbles this time and when the bubbles ended, I cranked her up and when it turned over tightned the nut and all is well. It is odd that the old pump would go out as the engine (I checked ) has 178 hours on it, though it is several years old. I have had the boat for two and a half years and have put about 100 hours on it, more than half on my trip to fla and back recently. The port tank is new, and the starbord tank is iron and original but has been maintained it seems. Both had clean fuel but I think there is some non algae crud in the bottom of the tank at issue (the iron one) I also treat the fuel each month, and my fuel line has an in line algee eater (for lack of a better word as I can't think of the name of it off the top of my head, but it is a circular devise that require no maintenance, that came with the boat. But I will inspect the tank anyway just to be sure. Thanks for the input. Care to weigh in on the in line dual filter issue, love to get some more insight on this. It would be easy to convert what I have. terry

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