also I hooked a gravity feed fuel tank to the pump overnight while it was on the bench no leaks there. I opened the bleed screw with the engine idleing & full throttle no air .
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I can't see the delivery valves being an issue....
When the line is full of fuel back to the injectors, you have the needle holding the fuel back, you also have the one qay valves in the pump holding it too... I'd find it very hard to believe it could be those parts.
I really don't know what else you can look at..... Its very odd. I winder if its compression related, you said over night it is hard to start, the engine has time to cool down so it wouldn't have the heat to fire right up.... Then it could be the govenor, but i don't know how....
skidsteer.ca
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If it is compression related, generally a little sniff of either (I know that swear word) will get it to fire, if the fuel is there as it should be then the engine will generally keep running. If it stall after the either is consumed, make me think the fuel is still not there.
Ken
This engine dosen't like (that swear word) I gave it a little sniff as you call it & she locks up. I do want to thank you guys for all your input. If I ever figure it out will let you know.For now I am just going to use it & grind the (you know what) out of the starter. tom
I think I know what type of fuel connections you have on that Isuzi , banjo fittings , there are either brass washers on the smaller ones and / or aluminum wahers with an o ring rubber inpregenated in the washer , those fittings have a tendendancy to leak and suck air into the system , I think I read where you hooked up and external tank but would bet you went thru the fuel filter head and tubing , what I have to check for that is an old school Detroit ZDiesel hand primer pump that I have a tee and a gauge mounted to and plumb it into the system which can be chalanginng if you have banjo fittings and not equiped with some adaptors ----- but from judging by the age of the machine , I think you said 80's , I would lean more to compression being low ---------you are right about them Isuzi's not liking starting fluid and locking up , gasoline on a rag held by the air intake is much gentiler
yes fishfiles you are right it has banjo fittings with aluminum & rubber washers do you think if i replaced all the washers that might solve my problem? i know she is old i got it from the original owner the hour meter says 3700 hrs. I will see if I can barrow a compression tester do you have any idea what the compression should be on this engine? thanks tom
I don't really know the exact specs for compression on that motor , but I would guess it between 450 to 475 and no more than 10 percent difference between any two cylinders , you will need a diesel compression tester which goes higher than an automotive set up and an adaptor to either go thru the injector holes or thru the glow plug hole , if your motor has glow plugs and not a intake warmer set up , which I think it may have , if it has glow plugs for the price of one plug you can make a adaptor -------------------------yes the washers will let air in and it will leak down over night or quicker , and you don't see it leaking externally , I have replumbed a couple of Takeuchi's which uses that same filter housing , to a regular style filter housing as we were always having trouble with those banjo fittings , did you ever find a plastic screen in the banjo fitting which sits on the inlet of the hand primer , a clear piece of plastic tubing , if you can plumb it into the fuel line right before the injection pump can help to see if air bubbles are flowing thru , I think you mentioned fuel in the oil , another way it can get there is the seal on the end on input shaft of the injection pump , ---------------- 3,700 hours is alot , but if it was properly maintananced I would think it would go over 5,000
skidsteer.ca
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Tom
If it locked up you gave it way too much. Might not take much some engines repond to the slightest amount and other drink the stuff like like fuel. If it did want to lock makes me think compression is maybe pretty good.
If its a fuel issue that needs to be fixed first. if the engine is just getting worn and compression is down some, either will help you get it started without wearing out your starter.
Check the compression first, so you know what you are up against, then remove the return fuel line and submerse it in a bucket of fuel, get the engine running and look for air coming out of the return fuel line, you can see the bubbles easily if your submmerse it. There should be no bubbles. keep working on the suction side until any bubbles are gone.
Ken
Thanks guys for all the good ideas going to take me a while looking for a compression tester now.p.s. this eng. does have glow plugs.
Well this afternoon I put the return line in a glass jar with fuel I got tiny bubbles for about one minute then seemed to clear up. Could I assume this was just air trapped in the 2.5 ft. hose i put on the return to the glass jar? As previsly stated when it starts it will idle only for about 1to 3 min. then pickup fuel & respond to the throttle had throttle full so I gave it a little sniff of either engine revved just a little bit & went back to idle so I gave it another shot it revved a bit then picked up the fuel & ran ok.
I think the air would be from when you put it in the fuel. I'd leave it over night and try it again though, with the hose still in the fuel. This way you know if its drawing air in somewhere.
When its running without bubbles, shut it down, leave it till the next day and re-start, see if you get bubbles.
Ok I think you fellows finaly figured a way to make me spend a bunch of money I kept looking for the cheap fix. I barrowed a compression tester today #1&2 cyl. wouldn't even show a reading #3cyl. had 375psi. I dont see how it ran so good. It dosen't have any blow by.could this be bad vavles? tom
It could be stuck valves.... You would need to pull the head off and get it tested for cracked and get the valves and seats ground.
Before you yank the head..... Check your valve clearance. You may be lucky enough for the adjustment to have screwed down somehow and it could be holding a valve slightly open. If you are getting no compression at all, i'd doubt it was a crack, if it was, it would have to be rather large to have no compression at all. If it uses rockers, get it to TDC and see if the inlet and exhaust rockers can be boved up and down slightly. If there is no gap, it could be holding the valve open slightly.
I hope its that simple!!!!
I was thinking maybe valve face could be rusty it sat for 6or 7 years. I did check adjustment that is ok & they are not stuck. I dont think that 1&2 have no compression just the gage I used started at 100psi. and it would bounce the needle just a bit. it was a cheap gage. I want to say thank you to everyone for all your input.I will report what i find out. tom
Somethings I could think of that you might want to do before you pull anything apart , do a wet compression test by putting a few squirts of oil into the cylinder and retest it , get a good teater that will hold the pressure , if the cylinder increases in pressure for a few rotations and goes away it is probally rings which could be stuck after 7 years , if not then it could be a stuck or rusted seat (7 years wow ) valve issue , I have a engine combustion gas detector , which are pretty cheap at Napa , it is a clear tube with a rubber bushing that you stick into the radiator neck with blue fluid in it , you run the engine and if the fluid turns yellow then exhaust gases are getting into the radiator , this would indicate a blown head gasket or crack in the head or block , also a radiator pressure hooked to the radiator with the motor running will show you if pressure is leaking into the cooling system ---------------
Just an update for you curious gear heads i think i have found the problem the govener is sticking. I took a plug off of the top of the gov. I saw a spring in there put some presure on it with a screw driver & engine reves up from idle to what the throttle is set at. now does anyone know how to get the gov. off the back of the pump? have removed 6 bolts all i see dosent budge. thanks again everyone.
Does it have its own oil that it runs in? It may pay to change or top the oil up?
I know the govenor on my compressor has its own oil for this exact purpose. If it got low i see it may allow for it to stick.
You may be able to harass an injector shop to ask them how to remove the govenor? I'm sure someone would be able and willing to assist you.
no the oil is pumped in from the crankcase. i have talked to some injector shops they want me to bring it in not to generous with info the elderly fellow who said my pump was ok said he doesnt know much about the gov. on the pump.[ ? ] going to change the oil & maybe put some oil supplement in. also a local machanic checking with some of his pump repair shops they might not be as tight lipped with him.thank you all once again. p.s. I looked through the posts tazza and remember you saying something about the gov. might be sticking but i went of in other directions.