Low IPP

[Harky]

Hi guys,

Looking a bit of info about IPP for a 1.9TD 306, think the pump number is 0 460 494 370 or very similar.

So I fitted a IPP gauge and I'm getting about 43.5psi at 1k, at mid 60's at 2k which according to this thread, http://www.vwdiesel.net/forum/index.php?topic=30765.msg277197#msg277197 should be correct.

Now the problem comes after this, the IPP never really gets above about 75-80 psi. I'm pretty sure I've seen a graph on here before that shows IPP rising on up through the revs to well over the 100 mark, mine just sort of stop's rising. As far as performance, I'm running a 100% standard pump while I rebuild my "good" pump so performance is naturally not great!

Just interested to know a. If someone knows what the IPP should be at greater rpms, and b. what would be causing the low top end IPP, worn vane pump, or fuel supply problems. Might also be worth noting that I run the pump on vegetable oil so its a bit thicker.

Cheers in advance,

Andrew

[mtrans]

My 0 460 494 189 go 100 psi, use jar to feed IP,thicker fuel must made more pressure,on wmo data.

[ORCoaster]

Harky,  Mix up a gallon of diesel and dissolve one of those four bricks of wax you can buy for canning, Parro Wax into the fuel.  Then put it in a jar or maybe use a diesel can, to run it off of.  Then watch your idle and top pressures for awhile.  This is a thicker fuel than that ULSD crap you are forced to by at most pumps.  If you can buy some B99 or B100 try that.  It too is thicker.  I suspect you have a worn pump and you will notice it when running this different fuel type.

I get up to 100 lbs on my IP with almost all the fuels I run, USLD, BioD and WVO.  Lower pressures at cruise with ULSD compared to the others.

DAS

[R.O.R-2.0]

Harky,  Mix up a gallon of diesel and dissolve one of those four bricks of wax you can buy for canning, Parro Wax into the fuel.  Then put it in a jar or maybe use a diesel can, to run it off of.  Then watch your idle and top pressures for awhile.  This is a thicker fuel than that ULSD crap you are forced to by at most pumps.  If you can buy some B99 or B100 try that.  It too is thicker.  I suspect you have a worn pump and you will notice it when running this different fuel type.

I get up to 100 lbs on my IP with almost all the fuels I run, USLD, BioD and WVO.  Lower pressures at cruise with ULSD compared to the others.

DAS

hes running WVO tho, its much thicker, and builds higher internal pressure..

[mtrans]

Or he put much temp?

[R.O.R-2.0]

Or he put much temp?

even at VERY HIGH TEMPS, WVO is still thicker than diesel...

[vegged-out]

I've noticed symptoms of lower IPP running grease in cold winter weather. the (grease) fuel filter is restricted until the fuel warms up and there is a vacuum in the post filter fuel line. Is your filter clean?
Michiel

[ORCoaster]

Didn't catch the VO line.  Thanks for the straight out ROR. 

That would change the equation and I think Vegged Out has it.  I warm the tank in the back up to about 85 degrees F before I turn the coolant circulation pump off.  It gets up there a bit more in degrees but nothing over 92.  I monitor the WVO temps at three locations; main tank, after two filters, and just prior to the IP.  Found these cool digital temp gauges that run off 12 volts.  One gives me duel temps as it cycles back and forth and the other steady temp. 

I also have a Vacuum gauge on the line between fuel filter and IP.  And if I am still cool at the filter, say 80 or so I do notice there is a slight 1-2 in vacuum until it gets warmed to near 100.  After that it seems to be the same as diesel. 

You could check the IP pressures off the individual source as I suggested to see what they are totally unrestricted and then hook it all back up and read it again. 

Does your fuel line have a rise in it above the top of the IP near the tank?  My second tank pulls fuel off the bottom of the tank but out through the top of the tank to do so.  Thus I have somewhat of a siphon effect going.  I have to watch that with low amounts of fuel as it will suck air into the line and we know that does wonders for the system now doesn't it.  I can't take the level down beyond about a 1/4 of a tank without running that risk.  Thankfully I have good mileage and a 10 gallon tank goes pretty far.  If I feel uncomfortable about the distance, I just pack a cubie of oil with me and throw it in at the 1/3 mark. 

Later DAS

[Harky]

Hi guys, thanks for all the responses.

Yes I'm running WVO so it is a bit thicker than diesel, especially in this slightly colder weather. Slightly blocked fuel filter is a possibility although it's not that long that I last changed it. On that topic, is there anyway to measure if a filter is blocked, some form of gauge on the fuel line, or is it even necessary? Surely I will always have a slight vacuum in this as I have no in tank pump, just the vane pump sucking from the tank.

[vegged-out]

I have a vacuum/pressure guage between the pump and the filter. I also have a fuel pump on the VO side between the tank and the filter. There is a heat exchanger post filter which is why I can get cooler VO restricting the filter but still have Hot VO to a hot engine.
Usually the fp gives me 1 or two lb. of pressure with hot VO in the summer. in the winter when I get indications of retarded timing at speed, fuel can be up to 10 in of hg vacuum.
I would always have the vacuum guage to monitor the filter and the fuel pump to prime and bleed the filter. Also helps for air leaks.
Michiel

[R.O.R-2.0]

you should heat the whole system, not just right before the injection pump..

[vegged-out]

I do. Tank heater ,hose in hose, heated filter heat exchanger. I'm talking about Canadian winter here. Sometimes I never get engine temp high enough for VO at all, even on a two hour trip!
Michiel

[ORCoaster]

OOOOwwww that is not good.  You have to find a way to get more heat from the engine.  Hottest thermostat is a 93 C isn't it?  I have an 86 and it seems to do OK.  I get 145 out of it on the long drive in cold weather.  You need to block off the radiator or something more or you will always have that high vacuum and that is not good for the pump, the timing at high speed or filtering.  I wrapped all my oil and heat lines with insulation and then wrapped that with strips of a space blanket.  You need to have some sort of airspace between the blanket and the line or it doesn't work.

Today on the drive up I started with my 10 gallons of WVO at 58 degrees and only had to go about 10 miles and it was up to 85.  I turned the pump off and it still continued to rise to 93.  Helps heat up the back end of the car that way.