CAV inj. pump rebuild or replace what would you do?

I just fully rebuilt my perkins ad3.152, had the head and valves done, new pistons, rings, liners, bearing, crank turned, etc.

I've been getting a loss of power and tons of black smoke. I pulled the air cleaner hose off to see if there was an air restriction and there was no change in symptoms...no rats nests or rags in the intake manifold either.

I was sure to put the inj. pump back on with how it came off, timing lines lined up.

My educated guess is the injectors or injection pump is not working correctly

After speaking with a few injector pump rebuild shops (both local and out of state) I can either:

1. Send both my pump and 3 injectors out of state and have them all redone totally (head and rotor reconditioned, injectors reconditioned (tested first of course)) this would be $695 for the pump rebuild and $100 for each injector so $1K total...but hopefully everything would be good.

2. First have the injectors tested and reconditioned locally to see if they are opening properly...this test runs $6 per injector. If they need reconditioning it would $40-50 each not including if I need to replace the nozzles which I think are about $35 a piece. For the pump, I can buy a new pump from Walt's for $681 new, and keep my old one...maybe sell it on ebay as a core...Walt's said cores go for $300 assembled, or $150 if I've dissembled it for any reason and couldn't put it back right.

3. Or have the pump rebuilt locally for $400-500 (not including the head and rotor). If I need the rotor and head redone the pump rebuild could cost $1,100 max.

I'm leaning towards first pulling the injectors and having them tested locally for $6 each. Then if they need reconditioning, having that done hoping I don't need new nozzles, so that would be around $150 and see if that fixes my black smoke.

If I need to have the pump rebuilt or replaced, the question is in the quality of the new pump, or should I just send it out of state for $695 and have mine rebuilt totally with head and rotor reconditioned.

What would you do?

If you got the timing set right when you put the pump on I would have the injectors tested first. If they are good you are only out $18. As to the pump I have had several rebuilt for less than $600 3cyl. and 4cyl.

When did the smoke problem start? Before the engine rebuild or only after the engine rebuild?
If the smoke started after the eingine rebuild, I suspect that pump timing is off. Need to post the exact detailed method you used to get it back in time. Experts here can chime in and walk you through the timeing process. Tom

OK, I took the injectors to the shop...they are going to test them in the morning. If they do need re-conditioning, does anybody know if this is this something I could, perhaps get the parts myself...or is there more to it?

Regarding Tom's reply, more accurately it started blowing black smoke after I replaced the lift pump which was at the same time I rebuilt the engine. The old pump produced only 1-2 psi of fuel pressure, the new one produced 8-9psi...it ran good for while on the new pump (no black smoke), then developed a leak...while I was waiting for a replacement I put the old pump on to use the tractor, no black smoke and the tractor ran good but would randomly die on me.

Then I got the new pump, put it on and I got black smoke. I ordered a different lift pump, one with a bowl, and this one ran good for while then would randomly die. I then got a fuel pressure gauge and tested all these pumps. The old one gave 1-2 psi, the new one gave 8-9psi and black smoke, the new bowl one gave 1-2psi and no black smoke.

I then bought an electric fuel pump and it gave 8-9 psi and black smoke...I then put a fuel pressure regulator on and reduced the pressure to 1-2psi and no black smoke, but also low power. That's pretty much the whole story. So I'm focusing on injector pump and or injectors at this point.

If timing the CAV is the issue, I would love to try that before rebuilding or replacing my CAV pump. If someone knows, please chime in.

Injector test results:
1. Opened at 2250 psi, dripped and had poor pattern.
2. Opened at 2400 psi, dripped and had poor pattern.
3. Opened at 2250 psi, did not drip and had good pattern.

So two will need new nozzles, and all will need to be gone thru and reconditioned.

Spec psi is supposed to be 2500 psi for used injector (over 25 hours) or 2750 psi for brand new injectors. These are old injectors.

you need special equipment to set the injectors up and you need to be careful because of the high pressure.

I have a MF135UK. Similar symptoms: mine would not rev up when the throttle was put to max. I would have to stop the tractor and wait until the revs slowly reached 1700rpm then the engine would take off up to 2100rpm. While using a snowblower the tractor would bog down too easily. I recently lost a couple of bearings and I've been rebuilding the engine. I sent my CAV pump & injectors out for a rebuild. The pump apparently was essentially worn out and the governor was misadjusted. The injectors also were in poor shape. The rebuilder said I should see a huge increase in power when I put the tractor back together. Hope this helps. Good luck.