Injection pump misfiring

[DROW]

Hey guys, new to the forum. I have a 79 300sd that I parked some years ago and bought another 79 300sd , I started the old one and ran it around the block every few months, then three months ago I adjusted the valves, rebuilt and balanced the injectors ran some diesel purge through, then a new fuel filter. Now it will not start. Anyway I have gone over the bases that I can think of ie running fresh fuel from a can, poured some oil into the injector holes to coat the cylinder walls made sure fuel was coming out of the delivery valves on the IP, went over the valvues again and exchanged the injectors with my other one. The thing I noted about the injection pump was that the valves are squirting fuel in the wrong timing 12453, different from the valve cover, and different from my other car. also with the injectors out when I turn it over it sounds smooth and turns easily like my other car but when trying to start it with them in it has a hitch. Could this be gummed up injection valves on the pump causing bad timing or maybe something broken in the IP.

[Diesel911]

There is no sort of distributor valve inside of the Fuel Injection Pump; each one of the Elements injects Fuel by a Camshaft inside of the Fuel Injection Pump.

If the Fuel Injection Pump is really is not injecting at the proper time there would have to be something wrong with what is turning the Fuel Injection Pump.

The other way it could be off time is if someone had removed the Fuel Injection Pump and re-installed it inproperly at the wrong degree marks or stroke of #1 Piston.

(This cannot happen on a Fuel Injection Pump that has been on a running Engine but with some Fuel Injection Pumps it is possible to install the Camshaft backwards during the rebuilding process.)

When I worked in a Fuel Injection Shop I did have one Fuel Injection Pump that was on a Vehicle that had a broken Fuel Injection Pump Camshaft. But, in the 5 years I worked there that was the only one (on a Mack Truck). The Truck ran badly like that but they drove it to our Shop!

Line up the Mark on the back of the Camshaft Timing Gear with the Mark on the first Camshaft Bearing Tower and look at the degree marks the Pointer points to on the Crankshaft Damper and see how far off the Camshaft Timeing is. If the Camshaft Timing is off the same Timing Chain drives the Fuel Injection Pump.

[boneheaddoctor]

How did you "rebuild" the injectors? You DO have a pop tester to set the pop points don't you? Have you verified the spray pattern as well?

Off the shelf "NEW" nozzles today are of horrible quality. And have a large failure rate.....its NOT as easy to do as you might think. I'm wondering if those were actually done correctly.

[Diesel911]

Originally Posted by DROW

Hey guys, new to the forum. I have a 79 300sd that I parked some years ago and bought another 79 300sd , I started the old one and ran it around the block every few months, then three months ago I adjusted the valves, rebuilt and balanced the injectors ran some diesel purge through, then a new fuel filter. Now it will not start. Anyway I have gone over the bases that I can think of ie running fresh fuel from a can, poured some oil into the injector holes to coat the cylinder walls made sure fuel was coming out of the delivery valves on the IP, went over the valvues again and exchanged the injectors with my other one. The thing I noted about the injection pump was that the valves are squirting fuel in the wrong timing 12453, different from the valve cover, and different from my other car. also with the injectors out when I turn it over it sounds smooth and turns easily like my other car but when trying to start it with them in it has a hitch. Could this be gummed up injection valves on the pump causing bad timing or maybe something broken in the IP.

If you rotated the Engine by hand were you rotating the Engine Clockwise when the Fuel Injection Pump was squirting in the wrong order?

[boneheaddoctor]

And if it was turned counter clockwise at all you may have damaged the timing chain tensioner and had it jump time.

[DROW]

thanks diesel911, I will check the timing gear against the crankshaft damper.
I use a pop tester from bergsma (**************)to balance and release test my injectors, monarch nozzels also (I run wvo, though not in that car) and I turned by hand clockwise off of the front crankshaft bolt.
I am thinking that the pump may have always been faulty, or installed wrong. when I bought the car ten years ago it was really loud and a little hard starting I didnt know much then about diesels and thought thats just how they are (my other 79 300sd is almost as quiet as a gas) the loudness was part of why it became the garage car.
It had the engine rebuilt at some point in the past, good compression on a high mileage car and added bolt straps for lifting it out. So maybe some shade tree mechanic failed to install correctly?

[panZZer]

try tightening up all the injector lines first.