internal injection pump pressure

[Fatmobile]

did you change the banjo or are you still using the 2 port banjo

If the little lines popped off or leaked It'd be kinda obvious and I wouldn't need a Guru

Tough question?

[sfmark1497]

Andrew, thanks for the clarification. I re-routed the injector return line to downstream of the needle valve, that makes sense. Unfortunately it didn't solve the low pressure prob. I'll try tapping down the the valve next time. If that doesn't work then I'll have to do that rebuild sooner than I planned and hopefully fix the vane pump. Great photos and descriptions!

Fatmobile, sorry to have sounded snippy. It was late and I had already read your post on the popping lines. I see your intenet now.

Hagar, I have upgraded my profile with more info but don't know any history on the car other than before immigrating to the States, it was born in Wolfsburg, Germany to the decendants of Dr. Ferdinand Porche. I re-read all of Andrew's posts, but don't see anything I missed. Cant find any Mark Shepard on the search function.

Thanks All!

[libbybapa]

Mark is Quantum-man.

I would suggest replacing the correct "out" bolt prior to adjusting control valve.

Andrew

[sfmark1497]

Andrew,

Do you mean:

A) Keep the original restrictor "out" bolt installed and use with the needle valve?

Or,

2) Remove the original "out" bolt and use the "big hole" bolt with the needle valve?

[libbybapa]

I mean install the original small hole specifically sized orifice bolt, open the needle valve and adjust the regulating valve on the injection pump. If you've tapped the valve in significantly without change then you might consider messing with the needle valve.

Andrew

[sfmark1497]

Ok, I got it. But I'll try to get the pressure with the needle valve first, then tapping the regulator valve... just cuz it's easier and should produce the same affect, I suppose.

[hagar]

Time to revisit this one.

hagar.

[hagar]

.SAGA : ---- somehow a TYPO sneaked in here somewhere ---so here are the numbers for you ALL one more time.
Numbers are from BOSCH and given for the 107 A pumps.

PUMP RPM first. 500 RPM 3 bar 750 RPM 4.1 bar 1000 RPM 5.2 bar.

so we can plot a line to 2000 RPM say 10.4 bar --EH ? ---ergo at 4000 RPM ENGINE ---about 150 PSIG.

hagar.

PS : now you see the problems ? with Twiggy fuel and OLD pumps ?-----by the way ALL the different types of BOSCH pumps here use about the same pressures.

[Fatmobile]

10.4 bar is about 150 psi,... 14.7 psi per bar right?
150 psi at 2000 rpm?

[Quantum-man]

Interesting..
I assume that the internal pressure is not linear with rpm; indeed it is probably more like a quadrant of a circle reaching some limiting pressure perhaps governed by lift pump tolerance else the seals would blow. Hagar did you check for pressure at say 4000rpm? 300psi?? Having a 'good' pump that reaches its maxium rated pressure may suffer if veggy oil is substituted.
A bad pump is better??
How much does the advance mechanism get limited by it's own internal wear?

...Step in Andrew's pietzo thingy...

[Quantum-man]

Interesting..
I assume that the internal pressure is not linear with rpm; indeed it is probably more like a quadrant of a circle reaching some limiting pressure perhaps governed by lift pump tolerance else the seals would blow. Hagar did you check for pressure at say 4000rpm? 300psi?? Having a 'good' pump that reaches its maxium rated pressure may suffer if veggy oil is substituted.
A bad pump is better??
How much does the advance mechanism get limited by it's own internal wear?

...Step in Andrew's pietzo thingy...

I see my thoughts are confirmed by that bloke 'Herges adventures of'... on the lookalike forum...

[hagar]

yes fatmobile 2000 RPM is correct and 150 PSIG is correct ---BUT NOTICE it is pump RPM --EH ? -- that is 4000 RPM crank.

and for old cock Mark Shepherd UK --(gloster kid) yes I did measure that.

Is it linear ? --not exactly , but I do think BOSCH was aiming for a straight line.

One thing I do not know for sure is when timing piston gets to full stroke. --but I do know that if it is not there at 150 PSIG --something is rotten in the state of Danmark.

Are you guys getting the drift of why hagar has so much FUN with Rabbits ?????.

hagar.

[hagar]

I am bringing this one up for coke , he asked me.

hagar.

[A1-2-A3]

Ok, I see you guys have done lots of tests on internal pump pressure.
I also see that some, not all of the tests are done becuase of:

1. Worn pumps(where is my pump at?)
2. Getting better mileage(the reason to drive a vw diesel!)
3. ULSD(Viscosity?)

Ok, heres a question...What is the viscosity differance from Low sulfur Diesel to Ultra Low sulfur diesel and what real pressure changes do these two fuels really have on the bosch pump. I think before someone went ahead and thought to make all these changes to these pump to fix the fuel "problem" It would be good to see there "is" a problem there.
Are there not any additives in the ULSD to make it "run" all the same.
I know some people here maybe have studied these fuels and maybe you already answered this.

I have heard you guys say that a bosch IP will run all the same with a little presure feeding the pump. Some of you guys run grease. How could a very slight amount of viscosity change in the diesel fuel(if there really is any) change the way your engine will run and affect fuel mileage.

You could look at my last statement and say well what about winter and summer fuels? They cause the engine to consume more or less fuel.
did anyone find the BTU rating of a certian quantity of summer and winter fuel? That might answer that one.

[Fatmobile]

I have always thought it was the wax being removed for winter fuel that made it get less MPG.
Was low sulfer diesel introduced before the '80s?
Reguardless of theorys on why the internal pressure might be low, I've measured it and it is often low,... around 20psi at 1000RPM on the last 2 cars I checked.