internal injection pump pressure

tawney · Post by **tawney** » Fri Feb 01, 2008 11:39 pm

Rally didn't ask about a pop tester; he asked about a top tester.

Pops and tops aren't exactly the same thing, I guess; at least pops don't have tops.

Perhaps what is needed is some way to attach the pressure gauge line to the TOP of the pump? Look back to page 5, (I think,) of this topic; there are pictures and discussion of at least 3 methods.

Steve

coke · Post by **coke** » Sat Feb 02, 2008 12:04 am

Can't do that method on an ADA pump though

At least not easily.

libbybapa · Post by **libbybapa** » Sat Feb 02, 2008 12:26 am

Sorry for the bad reading...

Andrew

coke · Post by **coke** » Sat Feb 02, 2008 12:32 am

Me too, my apologies!

Op-Ivy · Post by **Op-Ivy** » Mon Feb 04, 2008 3:01 pm

I'm going to be testing my internal pressure sometime soon. Perhaps when it warms up outside. But I have a question; Is it alright to not have the out bolt that lets diesel go back to the filter?

I see the setup that Stopping has wouldn't have it.

http://photos1.blogger.com/photoInclude ... Ptool2.jpg

Matt

tawney · Post by **tawney** » Mon Feb 04, 2008 3:40 pm

Is it alright to not have the out bolt that lets diesel go back to the filter?
I'm not certain; I think conventional wisdom is that it would not be 'alright', but according to the Bosch IP manual, when the pressure control valve opens it allows fuel to return to the suction side of the vane pump, so it seems to me it would maintain appropriate pressure regardless of a more restricted outflow. Edit: (I'm having second thoughts on that: the spring in the valve compresses because the pressure to the suction side of the pump is lower; without sufficient outflow, suction side pressure would increase and internal pressure would rise, although it might achieve 'outflow' (if there is no restriction,) by running back to the tank by way of the "in" bolt.) Maybe I'll try it and report back what I find. The Bosch manual also says that the 'pressure control valve and the outflow restrictor are 'precisely matched'; there must be reason. But even if it turns out to be okay to test the pressure that way, it wouldn't be good to run the car that way, because the flow of fuel acts as a cooling system for the pump.

Steve

rallydiesel · Post by **rallydiesel** » Mon Feb 04, 2008 4:48 pm

I think I was looking at Hagar's tester and it looked like it had no throttle assembly. So you just add a fitting beneath the return banjo? And you just read it with the car running?

rallydiesel · Post by **rallydiesel** » Mon Feb 04, 2008 4:53 pm

Oooooh, I like the method of tapping into the body and routing tubing to a remote gauge. I have had trouble finding banjo fittings so that would be the best way to go for me plus I don't have to worry about screwing up the the out restriction hole.

rallydiesel · Post by **rallydiesel** » Mon Feb 04, 2008 5:01 pm

So a gauge up to 180 PSI is enough? Is it ok to use an oil pressure gauge or do you need a special type of gauge?

coke · Post by **coke** » Mon Feb 04, 2008 5:10 pm

Oil pressure gauge is fine. The pedestals that were used on some of the later NA's below the out bolt are preferred, and that is in fact what libbybapa uses. Im still hunting one down. (Versus drilling the out bolt or using any other setup)

tawney · Post by **tawney** » Tue Feb 05, 2008 8:02 pm

Is it alright to not have the out bolt that lets diesel go back to the filter?

I tried it out in the garage: pressure with standard OUT bolt and steady stream of return fuel versus a bolt with no return: pressure was the same. Keep in mind, this is a pump on the bench being rotated with a drill at approximately 1000rpm: not exactly operating conditions in the vehicle, but it seems that if all you want to do is use it temporarily to adjust pressure, it might be alright.

I think what's happening is that the capacity of the pump at 1000 rpm is so much greater than the volume which the OUT bolt will allow to flow, that it has negligible impact on pressure to reduce the flow to zero; at lower rpms that may not be true.

Steve

tawney · Post by **tawney** » Wed Feb 06, 2008 9:50 pm

I was reducing the pressure on one of my pumps, and in punching the pin back upwards I'm pretty sure I confirmed a suspicion I had that the 'fixed' upper pin will not move back upwards until after the spring is squashed so compactly that it is permanently shorter than before: the pressure was reduced by half without the upper pin even moving. I tried it on another pressure regulator with similar, though less dramatic results. So I made a little tool to remove the spring stop at the bottom of the regulator shaft to use for future pressure reduction. I'm pretty sure that a shorter spring would result in a different pressure-to-rpm curve, though I didn't try to confirm that. Any thoughts?

Steve

58 special · Post by **58 special** » Thu Feb 07, 2008 9:56 pm

well i started reading this post and i must have reread it about 5 times now,
i took the route of tapping a spare OUT bolt with a pressure guage and when the motor is at idle shes about 26psi, kinda low but untill i get a tach, ill just watch it and see what happens.

i run WVO and diesel in my truck and i notice a difference btw fuels. it is slight however but you were talking about the viscositys of the fuel being different.
i notice that when my WVO is cool the car runns slower, and when the diesel is in there it runs fine. when the wvo is heatup at idle is still lower than with diesel, but my pressure guage still always reads 26 psi no matter which fuel i run.
so it seems that my pressure regulating vavle is doing its job no matter what the viscocity of the fuel.

just a thought but maybe it will help answer someones questions.
here is my guage taken off of an old air compressor.

i have still yet to tapp my regulator to see what happens but my mileage is around 39 and i would love to see it rise!

i need a tach now to adjust it better. im looking in a local junkyard to find a gasser tack to implant in my truck

Op-Ivy · Post by **Op-Ivy** » Thu Feb 07, 2008 11:59 pm

Nice job 58! Do you have any more pictures? I would love to see the fitting off of the pump if you have it! Where exactly did you tap in the gauge? I'm having a hard time finding a spot to plant a gauge. I want to avoid tapping right into my pump and I don't have another out banjo bolt to use on it.

Any suggestions?

Also, how do you make sure the gauge doesn't leak where you tap it into the pump. At 40 some psi it would have to be very tight.

coke · Post by **coke** » Fri Feb 08, 2008 12:21 am

40 psi is nothing.

At 4000 RPM its around 150 PSI.