Thread: Injection pump modification question

Hi All just to clarify the reason all this pump stuff started is I have an on going problem with my 85 county 4bd1 I brought about 12 mouths ago which i have moded. Into a 130 ute from a 4 door wagon also adding a turbo if you what the no. Look at the my fueling thread its the truck one also it has a air/air incooler the problem is at around 1/2 to 3/4 revs it misses bad is like the shuts off completly momentarily. after replacing or reco everthing before the ij pump including the injectors it hasnt changed .the concousion is the ijp has problems talking to a few ijp shops and getting told by a couple the pump will never work properly as standard to you have a advance timer prob. Ijp s fine but we need to get one from japan if they still make them and of course $$$$$$ you can understand my questions and thanks all for your help!!!!

This pump an AD ?
Thanks for clarifying what's on this pump John...

Originally Posted by Ancient Mariner

While we are on injector pumps if any of you learned gentlemen can tell me what those bloody lectric bits do I would be most gratefull

AM

My money is on the solenoid at the drive end being injection timing control.

OK but what drives it I think I read somewhere the fuel is reduced if the engine is getting
to hot but might be wrong ,If right will probably run OK

Originally Posted by Ancient Mariner

OK but what drives it I think I read somewhere the fuel is reduced if the engine is getting
to hot but might be wrong ,If right will probably run OK

I'd expect an ecu somewhere. It will be dynamic with rpm and load as a minimum.

I know that the pump frame is available with electronic advance control but I've never seen it.

I would take a guess that if you had the electronic advance control then you wouldnt have the mechanical version and without the ECU to drive the electronics it would be stuck at the static timing and you would either have to put up with knock at low speed or power loss at the top end.

someone with all the pump books in front of them or access to the suppliers sites and the numbers from your pump would be able to figure that out in under 5 minutes and this may be why people are telling you you need and advance unit.

Give me until Monday arvo and I can have almost everything you need to know about the pump...can you clarify all numbers on tag please?

Originally Posted by Adrian18

Hi All just to clarify the reason all this pump stuff started is I have an on going problem with my 85 county 4bd1 I brought about 12 mouths ago which i have moded. Into a 130 ute from a 4 door wagon also adding a turbo if you what the no. Look at the my fueling thread its the truck one also it has a air/air incooler the problem is at around 1/2 to 3/4 revs it misses bad is like the shuts off completly momentarily. after replacing or reco everthing before the ij pump including the injectors it hasnt changed .the concousion is the ijp has problems talking to a few ijp shops and getting told by a couple the pump will never work properly as standard to you have a advance timer prob. Ijp s fine but we need to get one from japan if they still make them and of course $$$$$$ you can understand my questions and thanks all for your help!!!!

OK, so the question about modifications to the injection pump was interpreted differently.

When a turbo is added to the 4BD1, it isn't necessary to have the injection pump modified. All the turbo does, which affects the engine, is to increase the pressure and temperature of the air to the inlet manifold, and increase the pressure in the exhaust manifold. None of this will cause a problem with the fuel injection pump. Nor will it require modifications to the injection pump.

However, one reason turbos are fitted is to improve performance. Now turbos permit this by providing extra air so more fuel can be burnt at the same engine rpm as before. This is what increases the performance, but unlike a petrol engine, to increase the fuel flow rate of a diesel the pump governor must be adjusted.

With the type of fuel injection pump and governor fitted to the Isuzu 4BD1 in our Land Rovers, all that is needed is an adjustment to the full load screw on the outside of the governor. It is not necessary to make other modifications.

The 4BD1 and 4BD1T is widely used for other applications, such as boats, excavators, generators, pumps, etc. Now these all have the same injection pump, but it needs to be calibrated differently and some need a different type of governor, for example a generator has to be driven at a constant speed, regardless of how much the load changes. Different markets, such as the USA have different requirements to us and so you see for example an altitude compensator added to the governor.

The type of governor fitted to a 4BD1 or 4BD1T for on road vehicle use is the Bosch 'RLD'. These are complicated governors and Bosch superseded them with the simpler 'RQV' governor for vehicle use. The 'RQV' governor will fit on our injection pumps, but is too wide and interferes with the engine block and oil cooler of a 4BD1.

Some places that service diesel fuel injection systems may not like the extra time and care required when calibrating an 'RLD' governor, but if they are Bosch certified they will have all of the information for every single part and adjustment from Bosch, cross-referenced to the Bosch part numbers on the labels attached to the pump and governor.

This will enable them to replace any unserviceable parts and re-calibrate the pump to as it was when new. If you remove the injection pump from the engine and take it to them it will save you $$$$. Explain the operating issues that need to be fixed and ask them if they can increase the full load fuel rate by, say 10%, because you have fitted a turbo. If you don't like their attitude, go someplace else (check this out before removing the pump).

Your problem may be the automatic timing device, or it may be as simple as the spring tension on the control rack. Or it might be o problem with fuel supply to the pump, e.g. air or insufficient fuel. The test bench will reveal what the problems are with the injection pump.

The timing advance specs for a 4BD1 are a little different to the 4BD1T, but not enough to be concerned about - this is not found to be an issue when a turbo is fitted to a 4BD1, i.e. there is no need to modify the automatic timing device (part of the timing gear fitted to the drive shaft (cam shaft) of the injection pump. the timing should advance 4 to 5 degrees at 1600 pump rpm (3200 engine rpm).