lost injection pump gear mesh

[venison]

well, guys, I think I have really messed up bad... When removing my injection pump, I did not realize that the gear it bolts to would be loose in the case. One of the hazards of being inexperienced...

So now I have reinstalled the pump, but while reinstalling, I realized that I have no idea if the gear teeth have aligned correctly or not. If it is off, I don't think it would be off by more than a tooth, but I don't have any idea how bad that could be.

If I attempt to start the motor and my timing is off, am I looking at potential catastrophic damage? I figure if it is way off, it won't start at all, but what if injection/combustion occurs early while cyl is compressing? that could be really bad couldn't it?

I am hoping to avoid having to pull the timing cover, but there isn't any other way to be sure the gears are aligned correctly right? Plus it would need to be at No1 TDC and I don't know how to get it there....

ugh

1990 Perkins AT4.236 w/ Lucas CAV (Delphi) rotary inj pump
MF 60HX-T

 

[massey240]

It will not damage anything being a tooth off and you will have a small amount of adjustment by loosening the pump and turning it that's why the bolt holes are oblong. You will know by the sound if its off a tooth but it more than likely stayed aligned they usually do. I just replaced one on a Perkins 4.203 4 cylinder engine myself

 

[massey240]

It don't matter if you move the gear 5 teeth off nothing will get damaged starting it. The pump injects fuel into cylinder when piston is always at top of cylinder. If the pump is off teeth it will inject early in the stroke or late while the piston is on the way back down.

 

[venison]

I'm not 100% sure, but I think that incorrect timing can damage things both in the engine and the inj pump.
At least that is my fear, otherwise i would try to start it.

I'm assuming that if timing is retarded or late, that is not as bad as too far advanced, but I'm just guessing at this point...

It don't matter if you move the gear 5 teeth off nothing will get damaged starting it. The pump injects fuel into cylinder when piston is always at top of cylinder. If the pump is off teeth it will inject early in the stroke or late while the piston is on the way back down.

 

[massey240]

Diesels fire off heat produced by compressing the air in the cylinder then injecting fuel into the mix. If fuel is injected to early not enough heat is produced so the engine will not run. I have rebuilt these engines many times over one tooth will make no difference at all

 

[massey240]

Diesels fire off heat produced by compressing the air in the cylinder then injecting fuel into the mix. If fuel is injected to early not enough heat is produced so the engine will not run. I have rebuilt these engines many times over

 

[Kenneth S]

It should be ok, really you would have to pickup the gear up some, and rotate it. Unless someone messed with it while it was sitting apart the timing should still be correct.

 

[banjodunn]

G'day as Kenneth said no probs we pull those pumps all the time and never align timing marks on the gears and as the pump will only go on one way on the gear then you are safe, the only thing we do is to check the scribe line on the mount of the pump and make sure they are lined up.

Bleed her up and get into it as stated earlier you will do no harm even if the timing is out ( which it won't be )

Jon

 

[Kenneth S]

the only thing we do is to check the scribe line on the mount of the pump and make sure they are lined up.
Jon

X2 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^