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 ** 60HX-T
Yes it could be bad to have the timing too advanced, but not likely. Rotate the pump to the most retarded end of the adjustment range and try to start it up. If it knocks at idle and cold then shut it off immediately and move it one tooth more retarded. If the engine seems smokey and low on power, then advance it back to where it was set and see what how it runs.
yes that makes sense... I sort of thought about trying that. I don't however know which way is which in terms of rotating the pump...
If there's not a timing window on the pump, you'll need to look in a manual to see a picture of the gear train to figure out which way it turns.
trying to attach pic: assuming black plate toward middle is timing window?
Yep, that's the timing window. If the injection lines aren't hooked up yet, loosen the nuts and crank the engine over and it will retard itself. Or wait for pumpguy to check in...
If that is a perkins as it appears to be, my experienceis it's a captive gear and can't come out of mesh without removing front cover. Pump also can only bolt on one way.
TEXAN has it right.. See the arrow on the name plate?? That's the direction the pump drive shaft turns.. Looks like a decent rebuild.. someone took their time.. what did you pay??
yep, Perkins AT4.236. I guess I would say that it was "sort-of" captive... Once the pump was out, there was a certain amount of play in the position of the gear, mostly front to back, but also up and down a little. I had to lift the gear and push it towards the pump to get it aligned with the pump when I reinstalled. Without seeing the inside of the case and the teeth on the gears, I really can't be sure if there was enough play for the gear to rotate significantly, as in a tooth or more. My gut feeling is, and based on how it looked before and after, if it moved at all, it didn't move by much. I guess my big question is still, if, theoretically, the pump gear did rotate slightly and re-meshed off by a tooth or two, and I try to start my motor, will I break anything? Because as far as I can tell, starting the motor will be by far the fastest and easiest way to see if there is a timing problem or not. I just don't want to turn it into a scrap pile if I've messed up the timing!
Hi there, in the UK we have thousands and thousands of these engines. Over the last 20 years I have no idea how many of these pumps I have changed, and have never saw the gear move a tooth in the timing case. Turn the key, even if it did move it is only fuel timing and has no effect on cam timing. Go for it, I'm pretty sure you will have no problems
well, after all the comments, I decided I should just try to start it. It did start, and then it died, just like it had been doing. So apparently the injection pump was not my problem. when it did start, for the little bit of time that it ran, it sounded pretty much normal as far as I could tell. I have a new lift pump, new fuel filter, newly rebuilt injection pump, fuel flowing steadily out the bleed screws on the injection pump when bleeding, fuel at the the injectors when bleeding, new air filter, even pulled the exhaust off in case there was an obstruction there, and still no start at all. After the inj pump rebuild did not solve the problem, I tried a different fuel filter thinking the one I had may have had a bad gasket or something... I bled the system to the injection pump, then cranked...It started immediately, ran for a couple seconds, then died and I have not been able to get it started again. Any ideas???? I'm totally at a loss.
Sounds like you still have more bleeding to do. If you bleed only to the pump there is air in your injector lines most likely. What we do to bleed the old Cats is to clamp a piece of inner tube or a pipe cap with a valve core in it on the fuel fill, put about 5 lbs of air in it and then bleed through the entire system.
You are correct! I just got it started after yet another bleed session. For the record, I have bled the entire fuel system, to the injectors, multiple times. Each time for the last 4 or 5 bleeds I got nothing (when trying to start), then I tried one last time and boom! She's running! Thanks everyone for your ideas and support! oh, and I think pump timing was unaffected as well; it smokes a little... sort of dark gray/black when increasing throttle, but seems as turbo catches up the exhaust clears up to barely visible. feeling very lucky right about now....