853 wont start

[Corvette02568]

Hello all, i just replaced the engine in my bobcat it has a Isuzu 4jb1 motor, we switched everything over machine won't run on its own, when i spray some either in it it start but as soon as either used up motor dies, we've bled lines i got fuel up to the injectors. the injector pump was rebuilt not long ago and was running on old motor fine before lower end leg go, any help would be great, we have check the fuel solenoid and it working so im just stuck on what could be causing it not to fire on its own.

 

[Corvette02568]

after searching some more on here i'm going to check pickup tube.

 

[Tazza]

after searching some more on here i'm going to check pickup tube.

You can try hooking up a bottle of fuel to eliminate the pickup tube. Hopefully it's just a pocket of air in the fuel system still.
Is the fuel shut off solenoid working?

 

[7LBSSMALLIE]

You can try hooking up a bottle of fuel to eliminate the pickup tube. Hopefully it's just a pocket of air in the fuel system still.
Is the fuel shut off solenoid working?

853 has a fuel shutoff solenoid at inj pump. I wire at tail of pump ensure it is enegerized. if it is pull it inspect operation of rubber *****. on solenoid

 

[mmsllc]

853 has a fuel shutoff solenoid at inj pump. I wire at tail of pump ensure it is enegerized. if it is pull it inspect operation of rubber *****. on solenoid

Re-check your fuel lines, I'm thinking the fuel supply hose & return hose might have been hooked up in reverse. If the supply hose gets hooked up to the return fitting, it will not be able to draw fuel out of the fuel tank. It is a very simple thing to check & it does happen very easily. The other fast way to check it is to try squeezing the fuel primer bulb. Does it pump fuel / get hard??

 

[mmsllc]

Re-check your fuel lines, I'm thinking the fuel supply hose & return hose might have been hooked up in reverse. If the supply hose gets hooked up to the return fitting, it will not be able to draw fuel out of the fuel tank. It is a very simple thing to check & it does happen very easily. The other fast way to check it is to try squeezing the fuel primer bulb. Does it pump fuel / get hard??

I'm guessing he got the engine to start by there being no further communication with him = GOOD for him!!

 

[Corvette02568]

I'm guessing he got the engine to start by there being no further communication with him = GOOD for him!!

sorry for delay i was on shift at Fire dept. i tired hooking up to aux fuel can same problem i get smoke but will not start, i took off fuel solenoid bench tested and seems fine and rubber looks ok, i'm starting to wonder about timing issue? is there easy way to bleed besides cracking the lines at injectors? im kinda lost as to why it won't start, simon

 

[mmsllc]

sorry for delay i was on shift at Fire dept. i tired hooking up to aux fuel can same problem i get smoke but will not start, i took off fuel solenoid bench tested and seems fine and rubber looks ok, i'm starting to wonder about timing issue? is there easy way to bleed besides cracking the lines at injectors? im kinda lost as to why it won't start, simon

Before installing this engine into your machine, did you ever see this engine run at all?

 

[Tazza]

Before installing this engine into your machine, did you ever see this engine run at all?

Smoke means fuel, or possibly if it's a reco engine, it could be assembily oil.
What happens if you spin it over and give a shot of WD40 down the intake manifold? Does it pop and try to start? (i have actually seen people use propane/LPG for this too, possibly a bit dangerous)
I'm wondering if the glow plugs aren't working, it could be too cold to allow it to start on compression alone.

 

[mmsllc]

Smoke means fuel, or possibly if it's a reco engine, it could be assembily oil.
What happens if you spin it over and give a shot of WD40 down the intake manifold? Does it pop and try to start? (i have actually seen people use propane/LPG for this too, possibly a bit dangerous)
I'm wondering if the glow plugs aren't working, it could be too cold to allow it to start on compression alone.

Propane is a great auxiliary fuel to help locate intake manifold / vacuum leaks on a lot of engines for diagnostic purposes. The only danger is when dealing with gasoline engines where the ignition fires with a intake or exhaust valve is still open. Otherwise, it should help determine if it'll run at all. How cold is it where this machine is? I mean, it could be almost anything wrong. Low compression, no power to the glow plugs, bad glow plugs, fuel supply / pressure problem or timing belt jumped timing / broken timing belt. Need more info / tests performed to know more.

 

[Corvette02568]

Smoke means fuel, or possibly if it's a reco engine, it could be assembily oil.
What happens if you spin it over and give a shot of WD40 down the intake manifold? Does it pop and try to start? (i have actually seen people use propane/LPG for this too, possibly a bit dangerous)
I'm wondering if the glow plugs aren't working, it could be too cold to allow it to start on compression alone.

machine starts with a shot either no problem and with wd40 also so we know its fuel problem.

 

[Corvette02568]

Before installing this engine into your machine, did you ever see this engine run at all?

Was a brand new motor so we did not hear it run before we installed it, but will fire when you give it a snort of Stating fluid.

 

[Tazza]

Was a brand new motor so we did not hear it run before we installed it, but will fire when you give it a snort of Stating fluid.

Has to be fuel, what type of injector pump des it run? rotary or inline? inline is pretty well fool proof, rotary you need to get it just right..
I guess it could be clogged injectors too. If they were sitting for a while, they could have gotten stock closed?

 

[mmsllc]

Has to be fuel, what type of injector pump des it run? rotary or inline? inline is pretty well fool proof, rotary you need to get it just right..
I guess it could be clogged injectors too. If they were sitting for a while, they could have gotten stock closed?

Injection pump timing, then. I am kind of curious how much you paid for this engine??!! What parts did you have to switch over from the old engine to this one?

 

[Corvette02568]

Injection pump timing, then. I am kind of curious how much you paid for this engine??!! What parts did you have to switch over from the old engine to this one?

Motor was brand new i paid $4000.00 everything new but injector pump and injectors, we used from old motor, is there any way to test the injector pump? i get fuel to the injectors when i crack the lines so im leaning now more towards timing issue?

 

[SkidRoe]

Motor was brand new i paid $4000.00 everything new but injector pump and injectors, we used from old motor, is there any way to test the injector pump? i get fuel to the injectors when i crack the lines so im leaning now more towards timing issue?

How did you time the pump? Belt driven timing chest, correct?
On belt-timed diesel engines that I have worked on (VW's), there are locking pins that you have to install to hold the camshaft and injection pump, then bring the crank up to TDC. Once you have that set, the pump timing can be fine tuned with a dial indicator. Then everything is locked down and away you go.
I assume it is something similar for the Isuzu.
Cheers - SR

 

[Corvette02568]

How did you time the pump? Belt driven timing chest, correct?
On belt-timed diesel engines that I have worked on (VW's), there are locking pins that you have to install to hold the camshaft and injection pump, then bring the crank up to TDC. Once you have that set, the pump timing can be fine tuned with a dial indicator. Then everything is locked down and away you go.
I assume it is something similar for the Isuzu.
Cheers - SR

the timing is gear driven, we followed the manual to line everything up to tdc.

 

[7LBSSMALLIE]

the timing is gear driven, we followed the manual to line everything up to tdc.

beining as youre knee deep in the hole already. I would suggest remove inj pump and send to qualified repair facility. its very inexepesinive. and A should never have to screw with it again. B. it outta the way and done. there is one in Louisville ky. that's always done me right. and you can speak with repair tech.

 

[mmsllc]

beining as youre knee deep in the hole already. I would suggest remove inj pump and send to qualified repair facility. its very inexepesinive. and A should never have to screw with it again. B. it outta the way and done. there is one in Louisville ky. that's always done me right. and you can speak with repair tech.

I think "7LBSSMALLIE" has a good point. It might be worth pulling the injectors out as well. Just ask yourself this question, "how much longer do I want to deal with this machine that does not run?" or "How much money am I not making while this machine will not start?" Have a knowledgeable (not cheap) diesel injection mechanic inspect / repair / rebuild your fuel system. If it runs good on ether, then you should feel as if you have done everything that you could have done. Think of the feeling of it running great for a long time to come........