internal injection pump pressure

[tawney]

3Bunnys, when you drill out that outbolt don't discount Fatmobile's comment about the process taking out the screen that's inside the bolt. Presumably the fuel is clean coming into the pump, but, going out, there are O rings and such in the pump that can disintegrate and potentially clog the tiny hole in the outbolt which would cause improperly advanced timing, and possibly other problems as well. I think it a bit unlikely, but 'Murphy' is always hanging out ready to prove that his law applies.

I just didn't want you to have some kind of problem that would delay the beer delivery!

[3Bunnys]

Yes we will be gentle when we drill.. want to just break thru bolt head ... not rip out screen ,,, will lean on drill press handle easy,,, with stop in place to limit movement..... better to have controlled enviroment such as lathe,,,, but don't own one...but a friend maybe....

So has anyone come up with a relatively simplistic/inexpensive method of detrmining RPM..... think I remember a post by "Westy??" that offered a $30/$40 kit of some sort..... I think the Blond is affecting my memory...

Richard

ps..Blond laws supercede all Murphy laws.... you have it easy if you only have to deal with murphy's laws!!!

[Fatmobile]

I saw a laser tach for about $40 in one of my catalogs.


.... I couldn't find it but saw one in eastwood catalog for about $90

[jettaman8691]

Hey Libby, thanks to your great picture of the modification of the out-bolt, I was able to locate an old one, have it drilled and tapped out, and made useful for testing the injector pump pressure. Thankfully, my old turbo pump hits around 48# at 1000 rpm.

This forum is the best.

[tawney]

Fatmobile, I checked out the photo tach at eastwood online, and it looks like the perfect solution to checking pump pressure at a given rpm in or out of the car; the $40 model would be a bit 'more perfect' though, if you run across it again.

Two weeks later: found a photo tach for $27 including shipping; it is so easy to use! In the garage or in the vehicle, turning the pump speed up to 1000 rpm and setting the pressure at 75psi is so simple. By the way all four of the old pumps I have checked so far were significantly below the specified pressure, 10 to 20 pounds low.

Steve

[mattbondy]

Ive been reading this post over lately. Would anybody be able to confirm a couple of things for me?

I have an old out bolt from an NA pump. So I just drill and tap a hole in it so that I can screw in a pressure gauge?

The pressure/rpm values given here are correct regardless of type of aspiration?

I probably will not do anything but get the old bolt drilled and tapped for the next little while. Any suggestions?

Thanks

[3Bunnys]

TAWNEY..... where did you score a $27 laser tach..... I don't think you're in competition with Jack on this one so you can probably post that info here...

Richard

[tawney]

Just do a search on ebay for photo tach; there are actually lots of them in that price range; very useful considering the low cost!

Steve

[A1-2-A3]

Photo tach I got from Princess auto comes with batteries, very accurate and under 50 bucks. But then again no Princess auto in the States, how do you guys survive without Princess Auto? Hey Canadian guys, is it not the DIY superstore? I get lots of ideas just walking into the store, just if I was not so damn lazy!

[mattbondy]

Princess auto is pretty incredible. They sell cheap tools under their power fist line which can be exchanged without a receipt for as long as they carry that product.

[hagar]

hagar sex YES The Princess is THE superstore for DIE types like hagar.

Rats I missed a fantastic sale of Surplus VOW seats ---by one day --cry cry.

That is Kanadian Snail Mail for us.

hagar.

[A1-2-A3]

Hagar I have two of those VW seats you speak of from princess auto and made a seat track out of the old 79 rabbit seat tracks, they are Vw ones and are THE same as Vw rabbits, they cost me 99 bucks each, I don't need them anymore so anyone in the Regina Area passing thru message and they can be your for the price of FREE!! They are grey vinyl one has 20,000kms sit time and the other maybe 5,000kms if that, so they cushions are like new(its FREE why am I rambling!!)

[Quantum-man]

[quote="
So has anyone come up with a relatively simplistic/inexpensive method of detrmining RPM..... think I remember a post by "Westy??" that offered a $30/$40 kit of some sort..... I think the Blond is affecting my memory...

Richard

ps..Blond laws supercede all Murphy laws.... you have it easy if you only have to deal with murphy's laws!!! [/quote]

Get a gasser witth a rev counter. Park it up to your diesel. Attach a cheap strobe to the gasser snowpeg mark on the sprocket of your choice. Use an assistant to change gasser revs to agreed indicated speeds. Match diesel speeds by pulling on pump lever. [Maybe second assistant to mark uncalibrated home made tach... Heck have tach inside engine compartment and make notes on scale... Or Something like that

[rallydiesel]

NOOB HERE: If your pump internal pressure is low, would getting a new transfer assembly (rotor, vanes and stator plate) be the best fix? This is assuming there are no leaks.

[tawney]

The transfer pump would worsen the problem. In a recent post I can't locate right now, Andrew pointed out that the advance mechanism in the pump operates off of the pressure difference between the internal pressure and the pressure at the fuel inlet, (inside the pump, the fuel from the spring side of the advance mechanism returns to the inlet,) so if you increase the pressure at the inlet you will decrease the pressure difference, and the timing will be more retarded than before.

Found it after the fact:

A lift pump will not assist the internal pressure situation, in fact it will often exacerbate it. The advance of the dynamic timing is dependent on the pressure differential between the pump inlet and the point just after the vane pump. Therefore if a lift pump is added before the pump inlet it will increase the pressure before the inlet and therefore reduce the pressure differential, consequently decreasing the dynamic advance.

Andrew