I'm trying to get a Cummins 4B engine running to replace a bad one in a Case 1845C. Don't know what it came out of but the CPL number is 0591 and it has a Lucas CAV injection pump. I've tried and tried and I cannot get it to fire off. Here's the rundown so far, Bled everything, could not get high pressure fuel out of pump. Removed and disassembled pump, found lots of varnish and rust inside, both plungers stuck in their bores, metering valve not stuck but clogged with gunk (I think). Cleaned everything out, freed up plungers, reassembled and installed. After a LOT of priming and cranking finally started to get a steady flow of unburned fuel vapor out the exhaust, but no fire. Took timing cover off, found pump gear lined up with letter "A," instead of letter "G" as per the data plate on side of engine. Changed gear timing to "G" now there isn't even any smoke. Does not seem to put out very much fuel though a loosened injector line, usually just a dribble, sometimes a spray. I'm at a loss. Could the pump just be worn out? Could I have assembled something backwards to keep it from putting out enough fuel? The engine seems to have good compression. What am I missing here?
How did you get the transfer pump rotor off to free the plungers? Did you remove the big inlet nut & check the filter & the movement of the piston? Post both pump name tag info.. & both cpl's.. ITS VERY possible that an injector is hung/stuck open..
I don't think I removed the transfer pump rotor. I remember seeing a tiny allen head bolt in the center of it but I couldn't get it out. I pulled what I think is called the "hydraulic head" out of the case, then removed the two twelve-point screws which allowed me to tap both plungers out as a stack. I did check the vanes in the transfer pump and the eccentric piece they ride in. All seemed well. I did remove the inlet nut and checked all the parts underneath. Screen was clear, plunger was free, and everything seemed to be correct. Here is the data plate on the pump. And here's the one on the engine. Now that you mention stuck injectors I did notice I could get fuel to squirt out of the cracked open lines for the #2 and #3 injectors, but not for #1 or #4. Does that mean anything?
You removed the 2-12pt screws?? THATS where you went wrong.. unless you gott'm back exactly where they were, you changed the fuel delivery.. Just because fuel wasn't squirting out of 1&4 doesn't mean a whole lot.. it just may take longer for the fuel to get up there.?? IF you wanna be sure.. take the lines completely OFF, away from the injectors.. a slight bend will be ok.. AND you could put your finger over the injector inlet to FEEL if it has compression coming back thru, while cranking..{2 people} Did THAT PUMP come with or off THAT ENGINE when you got it??
You are using the timing pin below the pump to find TDC, Right? THEN.. remove the side cover on the pump & letter "G" SHOULD BE lined up w/ the flat edge of the circlip..
I understood the risk of changing the delivery. I did scribe a line across all three parts before I loosened them and did my best to line everything back up when it went back together. I couldn't see any other way to get the plungers loose. Pump was on the engine when I got it. It looks original the paint is the same and everything. Yes I'm using the timing pin for TDC. I haven't looked through the side cover yet I'll try that. Can that circlip be moved or rotated out of position? I can't remember if I tried to remove it when I took the pump apart...
As long as you scribed a line you should be close.. so THATS OFF the table.. good. Yes the clip can be moved.. IF you moved it your screwed as far as getting the timing "perfect".. As long as "G" is in the window you should be close.. actually it should be closer to the top of the window ON THE PUMP.... WHAT G did you line up?? the one on the front gear?? Just do as in post # 5..
Your about the 12th guy THIS MONTH from NC that took their pump apart.!!! Is it somethin' in the water up there?? LOL.!!!!!
Well if they're like me they've been sitting around all winter wanting to work on something and as soon as it warmed up they ran right out and started tearing into things that that really should be handled by a professional with the proper equipment and know-how. Not a bored junk collector with a parts washer and a prayer. (Although I actually took my pump apart months ago). I'm pleased to report some success though! I changed the gear back to "A" because I found a Cummins service bulletin that said that was right, then I loosened the pump and rotated it AWAY from the head to try and advance the timing, then I gave it a shot of ether while cranking it over and it fired up and ran! BUT it runs very rough and smokey and doesn't want to idle. Also there is a huge fuel leak squirting out from where one of the delivery stems bolts to the hydraulic head.
The pump drive is KEYED.. If you moved the pump drive gear to A & that's right.. G in the pump will be showing.. THEN you can twist the pump.. The leak is just a line washer.. they are supposed to be torqued to 25FTlbs.. & there are 2 per outlet.. 1 on each side..
THAT would explain a lot. I messed with it some more and got it running pretty decent. It had a dead miss on #4 which was caused by the leak. I took the banjo bolt loose from the stem, flipped it over and bolted it back down tight and that helped a lot. It's still dribbling a little though so it must need new washers. The smoke cleared up mostly after running a few minutes but I noticed a concerning amount of blowby coming out of the breather. I'll mess with it more after I put it in the machine where I can run it with a radiator and under load. Thanks a ton for your help.
Checks in the mail?? Lol