[Chicago TDP]

OK, weird story, old trucker told me they use to, back in the day, take and plug the return line off of an IP and that would increase the injection output. Is this possible? Maybe put an electronic solenoid on a return line and clost it and see if the truck has more seat of the pants power?

 

[guybb3]

Someone on here said a plugged return is bad.

 

[dieseldummy]

They used to do that on old 2 stroke Detroits, but it won't help us out. I tried once and on my DB2 system it caused a rough idle and loss of power very similar to a plugged fuel filter. I've never done it on a DS4, but IIRC TDG mentioned that the results would be similar.

 

[damowman]

For these stanadyne rotary pumps plugging the return will just lead to problems; not more power. Return fuel from the injectors would leak all over. Perhaps that is so on older inline injection pumps; however it sounds kinda funny to me? Unless return fuel has something to do with the aneroid, not to sure on that one.

 

[dieseldummy]

I think the reason that they used to do it on the Detroits was because it raised rail PSI so it also increased injection PSI.

 

[DieselPro]

Pinch off the return line "on top of the pump" with vice-grips and see what happens. Won't hurt pump or engine.

 

[keith_2500hd]

outlet fuel fitting on DD has orifice, different size for different applications, just like Dieseldummy said. Cummins that used PTG(pressure time group) will work same to point (vt903's). need to understand fuel system completely before you change or adjust or might blow up engine or $$ parts.

 

[Fred482`]

Plugging the return line coming out of the top of the pump will increase the housing pressure. This, in turn, will retard the timing and eventually shut off the engine. Not sure on the electronic pumps but I know for sure on the mechanical pump. I've used the "pinch the return line" to test for a stuck advance piston many times.