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

 

[whis]

how do you know if the pump shaft is the same as when you removed it ? as far as the gear I don't it will be off unless you turn the motor. they will fall down a little but turn unless motor is turned

 

[venison]

Pump shaft only mounts to gear one way... there is a pin in gear and slot in shaft.
I have not turned the motor or anything like that, but the gear that bolts to the pump is held in place by the pump,
if that makes sense. when I pulled the pump out, the gear became un-meshed from the one that drives it and fell down
into the case. it didn't move far, but i had to lift it back up to get it to align with the pump shaft. So not sure if the pump gear may have slightly rotated when it became disengaged from the gear that drives it.

how do you know if the pump shaft is the same as when you removed it ? as far as the gear I don't it will be off unless you turn the motor. they will fall down a little but turn unless motor is turned

 

[whis]

it didn't rotate as long as pump didn't turn or motor you are good to go

 

[Zebrafive]

Since nothing rotated (engine or pump) and gear can only install to pump one way, it has to be meshed correctly to allow pump install. If you were a tooth off the pump would not line up to install.

 

[venison]

I had the pump rebuilt. The pump shaft was never locked in position. Had the gear stayed in place, meshed with the engine, rotating the pump shaft to match the gear would have put everything back as it was,
but if the gear moved, then the pump shaft was rotated slightly to match the new position of the gear, which would alter the timing. make sense?

I've been advised by a number of people that even if the pump's gear did not realign exactly with it's drive gear, it would affect the timing, but I don't have to worry about damaging the pump or motor (crankshaft?) if i try to start it. If it's way off it won't start; if it's off by a little it will run but poorly and I'll know then one way or the other.

Anyone want to support or deny that?

Thanks a ton

 

[JRobyn]

I would expect there to be some sort of timing marks on both of the gears. Probably on the "front" side. Can you finagle a small inspection mirror in there with a strong light to see if there is any mark on the engine drive gear?

- Jay

 

[whis]

if you turned pump to match gear you messed up. you need to pull front cover and line up timing marks and then have pump set again then install pump

 

[hosspuller]

Check your pump manual or manufacturer. There may be index marks on the pump showing TDC on #1 piston. Might be shown in one of the access ports. Then rotate your engine to TDC #1 piston. Mate the two together and you're all set. (At least that's the way Stanadyne sets their pumps.

 

[JRobyn]

Check your pump manual or manufacturer. There may be index marks on the pump showing TDC on #1 piston. Might be shown in one of the access ports. Then rotate your engine to TDC #1 piston. Mate the two together and you're all set. (At least that's the way Stanadyne sets their pumps.

OP has already said he has no way to do this.

- Jay