Wasn't sure where to post this, so I started here. I have a trencher with a Detroit 4-53 engine. It starts really hard after it's been sitting overnight, even in warm temperatures. It blows a lot of white smoke and I have to crank up the throttle and hold the key on even after it starts to fire or it will die. It will fire pretty quickly when you first try it, but it will die if you let off the key. After you get it started and running, it starts and runs fine after being shut off. My thought is the fuel is bleeding back to the tank after it sits. There is an inline electric fuel pump that was put on between the tank and the 1st fuel filter to address this problem. The pump is working fine. I even tried letting the pump run for about 30 sec. before starting it and that helps, but doesn't solve the problem. There don't appear to be any check valves in the system. I let it sit overnight and took off both fuel filters. The 1st filter (suction side) was about 80% full of fuel and the 2nd filter (pressure side) was about 50% full of fuel. What else should I be looking for?
Every two stroke Detroit I've ever worked on was fitted with a low cracking pressure check valve at the inlet of the primary filter. If yours doesn't have one, install one. I have a local hyd hose/fitting shop that has a good supply of various sizes of low cracking pressure check valves, should be pretty easy for you to source if you have a good local shop. Additionally, and not related to your problem, if you're using 15W/40 multigrade oil in the engine, please stop doing that, those engines don't like that oil. You need to use an SAE40 oil with 1.0% sulfated ash oil less, less is better. Delo 100 SAE40 meets the specs the best, Delo 400 does not, and there are others out there that meets that spec, just getting hard to find them.
Thanks for the info. What is considered low cracking pressure, 0.8 bar? I've found the online for cheap. I was thinking of putting a check valve as close to the tank as possible to keep all the fuel upstream of that point. You would put it right at the primary filter? Also, I am using straight 40W oil. You're right, it's hard to find.
Detroits usually have a gear type fuel pump and while your electric pump may push fuel, I doubt it can push fuel through the gear pump. It sounds like there's somewhere that air can get into the system and yet not let fuel leak out, weird but not uncommon. If the tank is lower than the engine, the return line from the head back to the tank will pull a vacuum from gravity and if there's anyplace air can get in, the weight of the fuel running down to the tank will suck the air in. The elbow coming out of the head where the return line attaches should have a restriction in it to create fuel pressure in the fuel rail for the injectors also. As Willie sez, there's usually a check valve at the inlet to the primary filter, especially if the filter is below the fuel pump.
I can't recall exactly what cracking pressure the proper Detroit check valve is, I just know I've worked on plenty that have that check valve fitted to the inlet of the primary filter. Like Lanway stated, make sure the fuel lines are good, leave no chance for air to suck into the system, and yes, as he stated, the brass fitting in the head that the return line hooks to should be a restrictor fitting.
If you are getting lots of white smoke on start up, you are getting fuel. The smoke is unburnt fuel. Chances are that there are some broken piston rings. The engine can not make enough heat on the compression stroke to ignite the fuel. Is this a new problem, or has it been coming on for some time. Do you know the history of the machine Has somebody been using either on it. One of my favorite tricks to start an old screaming jimmy that is showing her age is to pull the shut down and run the engine over for several second (10 seconds or so) then move the shut down back to the run position. This will get some heat in the cylinders and then the fuel will ignite better. Might take a few tries. One of the advantages of this is that you are not flooding the cylinder with unburnt fuel and not washing the sides of the cylinder and pistons. If you have a good set of batteries this works real good and no either involved. If you have an electric shut down, you need to manually overide the shutdown to keep it in the no fuel position. Hope this helps
I know this problem has been occurring for a while, the previous owner put the electric fuel pump on when they couldn't get it to start after they changed the fuel filters. There's no manual pump that I can see. The machine has less than 500 hrs on it, so it sat a long time at some point, but has been used a fair bit in the last year. I'm hoping the engine itself doesn't have problems with that low of hours, but sitting unused at some point for years probably didn't help anything. I do not believe they used ether and I haven't/won't. I'll check the return line coming out of the head. It looks like it's just a 90 and the manual doesn't say anything about a restrictor fitting. The fuel tank is at the bottom of the machine, so it may be getting air in that return line.
The fitting out of the head should have some numbers stamped on it if it is a restriction fitting. They look just like normal fittings but inside they are restricted, forget what size different engines used different sizes. OK did a quick look in a couple parts books and looks like .080 is the most common size for the 71 series, don't have book on 53. This should be stamped on the fitting, might have to clean off paint but usually easy to read. But like wornout wrench says if you have lots of white smoke you are getting fuel and the most likely problem is low compression. I'd be pulling airbox covers off the side and looking through the ports at the rings and poking them to see if they spring back nice, and looking through the ports at the cylinder walls to see signs of wear. Just got thinking, are there covers on the 53 series? Or will you have to pull the blower? Only worked on 3 or 4 53's in the last 45 years and the last one was a couple years back.
Just another thought, even though the hour meter shows what it shows, there is no guarantee that it is accurate. If you could find an old school Detroit guy, I would think about doing an overhead. You could probably do the valves, but the injectors are a bit of an art.
I'm hoping the hours are correct, but you're right, you never know what is actual. I'm no mechanic by any means. I'll pull that return fitting off to see if it has any markings on it.
Those vintage trenchers had steel welded tanks on them with steel pipe lines inside them. I'd isolate the entire fuel system, bypass the suction line and return line, install some rubber hose's and put a check valve in the fuel line where you shove the hose's into the fill hole of the tank, start it up and run it, shut it off and let it sit overnight, this will eliminate the fuel tank and lines for issues, and with a simple check valve installed on the line, you should eliminate the entire fuel system for issues. If its sat for any length of time, the tank will rust at the top and when got back using it, the rust will work loose and suck up into the line and lodge under the check valve seat, I'd also put an inline cheap fuel filter between the tank and the check valve to see if it gets plugged with junk. I just torched apart a steel tank off my trencher, the steel fuel pipe was cracked, not bad enough to cause issues when running but enough to leak fuel and get a slug of air in the line upon start up or shortly after causing the engine to die, I don't think that's you issue, but I do think you have junk in the tank and its plugging any check valve you may fin idn the system, allowing fuel to flow back in the tank and suck fuel out of the filter housing depending on where its located.
What are you calling vintage?? It's younger than me! Haha. Here are a few pics of what it looks like. It has an inline filter below the electric pump, maybe I need to replace that while I'm at it. First pic is the inline filter and inline electric pump at the primary fuel filter (oil filter is to the left). Second pic is the return side of the fuel coming out of the head (The 90 appears to be a restrictor fitting - it says R70 on it). Third pic is the secondary fuel filter and you can barely see the inlet side of the fuel line going into the head. It's behind the 2 red and 1 yellow wire bundle.
Classic senario of when either gets used. Engine will not start Get the either Hey, it started Give it another shot, and another, and another... you get the picture. I have seen it too many times. Fuel plumbing on a jimmy should be from the tank to the primary filter, primary to fuel pump, fuel pump to seconday filter, secondary filter to head, return line to tank with the orifice fitting in the head. Follow your fuel lines and you should find the fuel pump. It should look something like this http://dieselpro.com/detroit-diesel-fuel-pumps.html (I just used that link for the pictures, no idea who they are)
Yep, that's how it's plumbed.
I see in the last picture that there is what looks like a block heater cord hanging on the fuel line to the filter. One thing that might tell you something is if you are some place you can plug this in and warm up the engine before trying to start in the morning. If it does then fire right up with little cranking it would tell me that compression is the main problem. I know form past experience that a detroit with almost no rings left on the pistons will, once forced to start and warmed up a bit will run much better than you might expect. Wish I had taken pictures many years ago of the pistons out of a 12V-71 we rebuilt, almost every compression ring was broken, grooves about twice new width and this was in a truck that was being used daily in a gravel bed. Did need a sniff of either even on 80º days to start but once up to speed burned nice and clean for an old two valve head engine. It did strat a bit better with new pistons and liners along with many other new parts!
Good idea. I can plug it in and try that. I'm starting to think it needs an overhaul which is not an option at this point. Another thought - the battery is fairly weak, would replacing it help get the engine to crank faster and move the fuel better or does that not really have anything to do with it?
Is it turning over slowly or is your battery not lasting and you need to jump it to get it to start. If it is just tuning over slowly, but it does start, it is probaly not your battery but another problem like dirty terminals or a bad conection somewhere causing a voltage drop and dragging your starter down. Or, it could be a bad starter too. But the faster you can get it spining for start up the better. I would go with kshansen's idea and plug in to see what is happening. As far as either goes, it is not a bad thing if used the proper way. Too many times i have seen a guy dump 1/2 a can of either into the air cleaner and hit start. Argh!!!! Since Cat went to direct injection, and how long ago was that, they have start aid on the machines. It is either but delivered in a small metered dose right into the manifold. The small little poof gets the engine to light with out causing the damage that a huge dose does. If your machine is still running and doing the job you need, and the dollars are not there to rebuild, installing a either start system could be an idea. Those old jimmy's were tough old engines, they will run with multiple broken rings and still do okay. Depending on how much you use it, you could go years before you need a rebuild
Chech the valve lash. Sounds like they are out of adjustment
It turns over slowly, but it always starts and doesn't need a jump.
Agreed, a tune up would be in order, if nothing else other than to see if it is all within spec.
Rebuild the starter as well, so it can spin the engine faster. Keep an eye out for a replacement engine so when it dies for good you can swap them out, is my advice, I'd never spend much money on that engine if the rest of the machine was good, what's it in a Vermeer trencher?
Yes
Might be just me but if I had a use for the machine and the engine was installed where it was possible to work on in place I'd order a set of cylinder kits and a gasket set and take an easy weekend to swap them in. This of course after I had determined worn rings or liners were the real problem. I'm a little leery of buying a used engine even if you can hear it run, unless it is set up exactly the same as the one you are replacing you can get into a good deal of work changing things to fit it in. One thing I just thought of that the OP could try is to remove the exhaust manifold and start it up. This can let you know if there is a problem with just one or two cylinders or injectors. Sometimes an engine will have water down the exhaust and cause problem in one cylinder. But if pulling it down to fix one I'd do all of them, don't want to have to go back in a second time.
If it acts like it is losing prime it may be the seal on the drive side of the mechanical fuel pump. I have had them leak down when setting overnight but work fine when running. Look at it when the electric pump is running and see if you see any weeping. About $5.00 for the seal online.
If you have an electric fuel pump installed, make sure one of the plugs is out on the mechanical pump so you can see it leak, someone put the plugs in on mine and it ran fuel into the engine oil cause there no place for the fuel to leak out of when the seal goes bad on the mechanical pump.
I use to run some of these GM diesels , I would run the over head and put a set of injectors in it. The 40 weight oil is a definite. The thing about these motors , they make good power even worn out. Lots of times the rings will stick or gum up and not seal do to idling the engine to long. These things like to run WFO.
Here is an update on what I've done so far: 1. Plugged in the block heater for about 30 min. when the temp was 80F. It started noticeably better, but still not as fast as I would like. 2. Replaced the inline fuel filter with one that you can see through to inspect. It had some pieces of rust and junk in it, but it was not plugged. It started a little better after doing this (didn't plug it in again) but still not great. 3. Installed a check valve just below the primary filter. Fuel did not appear to be leaking from there back to the tank, but now that I have the see-through fuel filter installed, I can keep an eye on that. Started about the same after installing the check valve. 4. Replaced the battery. It cranks faster, but doesn't start any better. My next step is to plug it in for at least an hour and try it with all of the above combinations already in place. Seems like all the signs are pointing to low compression or something else wrong inside the engine.
Here are some basics that might help out. A typical fuel system is set up like this; tank-fuel line to first filter, which is the strainer, to the fuel pump, to the second filter, which is the sock style filter and is actual a filter and not a strainer, to the head which is drilled to allow fuel to pass to the stands where the jumper lines connect to the injectors, fuel flows in a line from one injector to the next, finally the excess fuel leaves the head through a restricted fitting. You should see an R stamped on the fitting. If not, pull the line and check to make sure there is a small passage instead of a regular sized hole in the fitting. It should be in the neighborhood of .080 in. The restricted fitted keeps fuel pressure higher. Also, it is critical that the valves are adjusted properly. If you are spinning the engine at a good rate, it is either out of time due to faulty valve clearances or you do not have compression. When I was doing a lot of Detroit work I always used a go-no go feeler blade to get an exact setting. Good luck.
The more I think about this, if you do not have the proper restricted fitting in the fuel return portion of the system, it will cause insufficient fuel pressure for starting. See marking on the example in the photo. This one is for a V-series engine with 2 heads, but the marking is what I am talking about. Good Luck.
I called my local Detroit shop and they said it's supposed to be an R70 fitting, which is what's in there now.
Too bad. If it wasn't in there, it might have solved the problem. Back to the grind.
One the side of the block opposite the blower side, is there a stamped steel plate bolted on there? If there is I believe removing this will let you see at least some of the inlet ports in the cylinders and if you watch those ports in the liners while turning engine by hand you should be able to the rings on the pistons. You should be able to take a small screwdriver and push in on the rings and see them spring in and out. Top ring is the most important to check but all should have springing action. Also if you turn engine over to get the piston below the ports you should be able to look in and see at least part of the cylinder wall. If you are getting white smoke when starting and after starting while cold it is very strong evidence that you have a compression problem. A couple things you could check on the fuel side are return flow and condition of return fuel. I don't have the spec's for a 4-53 but a 6V-71 should have about 0.80 gallons per minute so I would expect the 4-53 to show around 1/2 gallon a minute at high idle return. Anyone here know the actual spec? The other thing to be checked in relation to return fuel is to look for air in the fuel. Submerge the hose from the restriction in a bucket of fuel should be very few if any bubbles. Did some digging and found the spec's for a 53 series engine. 0.6 gallons a minute at 1200 rpm.
If you get the air box covers off to inspect the rings you should see an indent or line in the middle of the ring, If you do not see it, the ring is worn and needs replacing.
I plugged it in this morning for about an hour and a half. Temps were in the 70s. It fired up after about a half second and stayed running on its own at idle. I didn't throttle it at all. Tearing into the engine and replacing things is not an option at this point, so I guess I'm stuck with it. At least it runs. Thanks to everyone for the help.
Well I think that does lean heavy into the direction of broke/worn/stuck rings. I would prefer to tear it down and rebuild now but if it has good oil pressure and is not making any "Bad Noises" don't see too much wrong with getting project(s) done first. Don't tell the EPA I said that, then again they would not be happy about this 2-stroke anyhow! I know some will say any Detroit makes bad noises!
I have an old 4-71 Detroit that for years now has such low compression that I only have one 27 series battery in it to start. It spins like crazy when starting. It takes a puff of ether to start it when cold even in the middle of summer but it starts down to +15 F without any other aid. It still holds good oil pressure and seems to have enough power to run a hydraulic bank that needs 70 HP so at least it has that much left. Amazing enough it only uses about 2 quarts of oil in 25 hours. Runs clean as soon as it warms up.
Thanks Kshansen. If the oil pressure gauge is accurate, it seems to have good pressure. It's on the high side when it's cold and starts dropping as it gets warmed up. It needs to make some money before it's overhauled.
Those old Detroits, if they have the two oil filters, small and large, the bigger one is a bypass filter.. if they have any oil pressure at idle, they're fine. Best not to let them idle or run unloaded for long in any case, they like to run fast and be pulling a good load all the time, that's what they were built for.
Old-Iron, wish I could get hold of the 4-71 that has been just sitting for probably 15-20 years where I worked for you. It was originally the power unit out of a NorthWest crane that was scraped. Another guy and I rebuilt it and upgraded it to a four valve head with N-65 Injectors to be used as a PTO unit to run a Jaw Crusher. Was only used for a few months then when that project was done it was put in the store room where it has been since then. If you could look at it today you would think it was rebuilt last week other than a little dust on it. The last week I worked in April I put a good used battery in the battery box and after less than ten seconds cranking it fired up and burned clean as the day it was used last. Has the complete emergency shut down system on it and was converted to spin on filters and upgraded to an alternator from the old generator, new Donaldson air filter and muffler, paint not even burned off the exhaust! No sign of wet staking! Company has no use for it but thinks it's worth it weight in gold if someone tries to buy it, will end up in scrap trailer some day I'm sure, very sad:crying
Not You , have you worked this engine yet? Chances are if you have not run it , it could get better. Run the crap out of it , if you run it at night under a heavy load you might see sparks come out the exhaust , this would be carbon breaking loose. The rings can free themselves if stuck by running it. The bottom ends of these engines are built real heavy. When you start it , warm it a minute or two and its go time. What is the motor in?
It's in a Vermeer trencher. I've only run it a few days. Once it gets started, it runs fine.
Take the air box covers off the side roll the engine till the piston is below the intake port. Spray a little pb blaster in each cylinder. Roll the engine over by hand after and circulate the pb blaster. Let it set over night or until you go to use the trencher. When you crank it run the living **** out of it. You'd be surprised how much this can help.
Update. Been running the trencher 30 hrs or so. It does pretty well most of the time. It still starts hard even when it's warm outside. Every once in a while it starts sputtering like it's running out of fuel. If it's throttled up, it'll idle way down and usually catch itself and throttle back up. It's almost like it's getting bad fuel (which it's not) or hitting a really heavy clay area that is bogging the engine down. A few times it's even killed the engine, but always started right back up. I changed both fuel filters, and that didn't help. I'm assuming some of the problems mentioned above are still in play, maybe bad injectors? Just curious, I'm gonna run it till winter if it'll let me and then make some decisions.
Make sure the valves are adjusted correct. It makes all the difference in the world when starting the engine and overall power.
Seems like a lot of extra crap being bolted on without addressing the root cause. I would get rid of the inline filter, it's already got a primary and secondary. Test the fuel pressure, and also remove the output line from inline pump and test the pump. You really shouldn't need that inline pump either. These things have been running for ever around the world without an inline fuel pump. The restrictor size is correct, R70 means 0.70", best way to check the size is to get a small drill bit that is same size and poke it in the hole. Maybe pull it out and check that some dumbass didn't drill it out. If you don't have the tools or know how, get your local Detroit dealer to carry out a compression test, test your injectors and give it a tune up. Would be money well spent.