Injection pump timing

[RCCUMMINS89]

I lost power but I also took out my worn out Denny t fuel pin and pit back the one from Ind. Inj. Its not as good as the Denny t one. I figure the electric pump would just keep a constant fuel pressure to the diaphragm pump. I don't trust electrical pumps to run one alone. I have had to replace way to many electrical pumps in my day to have my mechanical diesel be crippled By a. Electrical fuel pump when it dies.

Then why run an electric at all?

However.......I'm going to say you gained bottom end because of the less aggressive pin. As far as top end? Hard to say, I've never seen an II pin and don't know if they are cut deep enough for full pin travel.

However... with greater timing, you'll see a lot less smoke. And of course like you know... smoke DOES not equal power.

[tim curran]

So help me understand this better. I have been running this set up for 100k or so. Both pumps were new at the same time. The electic pump is a diaphragm pump that you can suck fuel fuel through I made sure it would so that if it dies on the road I won't be screwed. I figure more fuel going to this pump wouldn't hurt a bit cause the truck is always returning fuel ex specially when at an idle. The diaphragm pump is pressure relief right kinda like when you prime that pump when it is up to pressure it is easy to push. When my first diaphragm pump went at 200k. It was sucking air and truck didn't like to start. I believe there is a weep hole to prevent fuel from leaking into the motor when the seals go in the pump. Please fill me in cause if I need to change something up I will

[JimmieD]

I already filled you in. As I suggested, bypass one pump then the other to test if that's the problem.

[tim curran]

I am running this set cause when I first started playing with my truck I had five inch stacks I was young and dumb and I could make a full size truck disappear in my rear view mirror with my smoke. Nobody with go through a four way intersection after I floored it cause the couldn't see. The crowds at truck pulls love to see smoke fifty feet in the air. When I put the truck on a Dyno my numbers sucked 215 hp and 612 torque. The guys at diesel fuel systems in Bangor said my truck was starving for fuel and add an electrical pump to take some of the stress off of my mech. Pump. Since I've played with so much stuff that I don't no if it really helped. The II pin not half the pin the Denny t pin was. My Denny t pin was soft and it caused my latest fuel leak in my inj. Pump. I will see if they make better ones and give it another go. Would an air dog setup help then take my old set up out completetly. I run a higher micron filter on the block and a big water seperator on the frame. I thought the electric pump would help with the added stress of the other filter.

[DodgeFreak]

the mechanical will leak fuel into the engine....there have been several people that have filled their crank case full of fuel.

[tim curran]

You guys running stock pump with maxed pumps and big injectors.

[tim curran]

That just happens to me and I thought it was the seal on the injection pump. I changed the oil after the repairs I'll check it out in the morning see if I am gaing oil again. Isn't there a weep hole to stop internal leakage .

[cougar]

You guys running stock pump with maxed pumps and big injectors.

Big is relative, but my stock lift pump wouldn't keep up with the 7X.010s I had. So going to a low pressure piston lift pump cured my top end loss. Mine was the lower pressure Delphi 701. I wanted a pump that had about the same pressure as the stock diaphragm, but much higher volume.

[tim curran]

We're did you get your pump

[DodgeFreak]

the hungry diesel (Rccummins) sells a true high volume low pressure piston pump.

[cougar]

We're did you get your pump

Oregon Fuel Injection. Ain't nothing wrong with the Delphi pumps. You can use a 701, which is the lower pressure or you can use the 702, which is the higher pressure 15-18psi. The Cummins pumps can provide even more volume, you just need to decide if you need it vs the higher cost.

[RCCUMMINS89]

Keep in mind Cougar.... ALL of the "factory" low pressure pumps have a 1" piston. Where as a "high volume" pump has a 1 1/4" piston....thus moving a lot more fuel.


As far as the Delphi pumps......nothing wrong with them. The one most people use only pushes about 8 psi at idle and just doesn't move really any more fuel than the factory diaphragm style ( a little more fuel, but not much ).

[cougar]

Keep in mind Cougar.... ALL of the "factory" low pressure pumps have a 1" piston. Where as a "high volume" pump has a 1 1/4" piston....thus moving a lot more fuel.


As far as the Delphi pumps......nothing wrong with them. The one most people use only pushes about 8 psi at idle and just doesn't move really any more fuel than the factory diaphragm style ( a little more fuel, but not much ).

I did, that's why I threw out there "relative" and "you need to decide if you need it". If your going with all the really big fuel mods, then you will need it. But, like I said for reference, it fed my 7X.010s all the way to 3200rpm with no problem. Though it probably wouldn't do so well with a 5X.016. Sounds like another test project.

[RCCUMMINS89]

???????

I've done personal testing with the pump I offer and that's all. I've tested them with stock injectors all the way up to injectors larger than 5x16s where the 15 psi pump maintains about 6 psi.

As far as the Carter low pressure pump (the 15-18 psi) one..... I've had my pumps replace those pumps and maintain 5-6 psi more with a 5x14 sized injector. Customer was pulling 18 psi at idle with the Cummins pump and dropping it down to zero.... put the 15 psi high volume pump on and maintained 5-6 psi.

As far as the Delphi 8psi one.... I've seen stock injectors drop those to 0.


Point in all the above.... I've done all the testing that I'm going/needing to do with the high volume pump in comparison to the std. low press pump. FYI.......there are 2 successful 14mm h/r pumps running around with the high volume pump with a custom 20 psi spring....I have NO IDEA how they are still alive.

[rockmike]

FWIW I ran the Delphi 702 and was able to pull in down to near zero I talked the hungry diesel(eric) and bought the high volume pump he sells and I have yet to get it to drop below 8psi the truck made more power using that high volume pump.