My diesel Ford 4500 with CAV pump did something odd the other day, it stalled at idle. After trying to restart it several times, I bled the lines at the injectors and got it to start. It was fine until the next day. It stalled again at idle and I got it to start again by only bleeding the #2 injector. It has happened a few times now and every time it can be restarted by bleeding #2 injector. Any ideas on what is causing this? I do know the pump fittings are leaky and it does seem like the flow when bleeding #2 is weak compared to the others. Is it just time to rebuild the pump?
Here is a pic I got of the id plate on the pump.
One injector catching air, or failing to function in any other way, won't make an otherwise good running 3 cyl. Ford shut off. If it is skipping, the normal thing to do is loosen the injector lines one at a time, until you find the one makes no difference. Normally, when I go to one of these that won't start by bleeding the filter and the side of the pump, I take just one line off at the injector and bleed one and it will start. In other words, unless something is wrong, they'll run on two cylinders, and will usually run on one. Sounds to me like a small air leak on the suction side, maybe combined with a fuel filter that isn't stopped up enough to cut your flow, but just enough to add resistance to make it easier to pull air than fuel. If you have RPMs up, the engine can pull a little bit of air and just dump it down the return line. I'd fix all possible leaks, particularly on the suction side, before I blamed a pump.
If you're getting air coming out of #2 injector line when you crank it over with the line loose it could be that the valve in the injector is leaking and letting compression back into fuel system.
Mitch is absolutely correct.. right down to the partialy clogged filter.. MT is correct also but I don't think it applies on this one.. I'd check anyway, just to rule it out.. If changing the f. filters and replacing lines doesn't work.. let us know and I'll tell you how to clean the "hidden filter" inside the pump..
How easy is it to change injectors on this engine? If other things don't resolve the problem how about swapping say #1 with #2 to see if problem moves with the injector?
My main point was that these engines will run with one injector line off, usually will idle on one cylinder for a few minutes. If it's shutting off, it ain't a problem in one cylinder.