To lower or not to lower or to leave it as it is the injectors pop pressure? - Page 2 - PeachParts Mercedes-Benz Forum

Alastair · #16 11-19-2010, 05:48 PM

Quote:

Originally Posted by scottmcphee

Oliver, when you are pop testing your injectors I know you will temped to put your hand under the stream to see if you can feel the difference between 125 and 150 bar. Don't put any body part in the stream, even though it looks like harmless mist, OK? Promise me that.

Yup, VERY valid point!

To do so, is the Quickest and Easiest way to get blood-poisoning,--May even kill you....

The Pressure and nature of the spray will easily penetrate the skin with desasterous results...

Luckely, I believe Olivier takes the injectors to a diesel-place to re-set, I dont think he does it himself....

Olivier · #17 11-20-2010, 05:56 AM

Indeed I take it to a place, I have not the equipement to do it.
I should have say that the glow plugs were bad at 135. And from what they say on the cold start link, it might be poor pattern.
this is why I am thinking that 145/ 150 might increase the proper pattern spray.
But Alastair you are saying that the droplet/ spray will be similar at 125 and 145? Is that correct?
All the best.
Olivier

layback40 · #18 11-20-2010, 08:19 AM

Oliver,
In your situation I would be inclined to set then at the standard setting of 145 bar. I would go so far as to say at those pressures, a change in pressure of 10 bar will have very little effect on the spray pattern. It may be beneficial for you to get heat tracing for your injection lines & injectors. This may help on cold start. It could be linked into your glow cycle including after glow or just have it on when ever the ignition is on.
The hotter you can get that oil just before it is injected the better for your single tank system. Best you try and get some very light, thin oil for the colder months.
You probably know that I dont have much faith in what you are doing & I dont believe that you can get it to run on WVO as well as it will on diesel or bio but you are welcome to try.

Olivier · #19 11-20-2010, 12:19 PM

Hi Layback,
The bother is that even if I heat up the oil there is no way I'll be heating it in the injectors where it'll be fired up the first time anyway. And there is a good lengh of pipe between the IP and the injectors. I am wondering how long it'll take for the oil if I heated up to go from the IP to the injector? Might be few revs...
There was some inline heater that might be helpfull, but they'll drain the battery fast I reckon... Oh well...
Thank you.
Olivier

layback40 · #20 11-20-2010, 06:29 PM

They do drain the battery fast. They are heat trace wires & are in some WVO kits. I have seen it used to keep the fuel warm all the way from the tank. Thats why some people put humungus alts on their cars.

scottmcphee · #21 11-20-2010, 07:00 PM

Quote:

Originally Posted by Olivier

Hi Layback,
I am wondering how long it'll take for the oil if I heated up to go from the IP to the injector? Might be few revs...

It takes about 4 to 5 seconds for fuel to get from the IP to each injector, when driving at highway speed. If you are idling the car, about four to five times as long.

Keep in mind there is a volume of oil sitting in the injector itself, and is at cold block temperature, no matter how much you heat the lines first before starting. The temperate of your first several revolutions will always be cold on cold starts.

Adding between 25 and 50 Watts of energy to each injector line takes between 12A to 24Amps (drain on the battery). 50Watts is enough to heat the contents of the line in about 1 minute to an acceptable VO temperature (80C).

Keep in mind also, you are competing with glow plugs pulling maybe 60Amps. And after all that heat, you ask the starter to crank over a very high compression engine. In cold weather, you're starter is competing with frozen crankcase oil.

This is why a very hefty batteries are used for diesels.

You alternator is maybe 75A.

layback40 · #22 11-20-2010, 07:35 PM

Scott,
How do you work out your currents?

Current = power(wattage) / voltage

12 amps at 12 volts gives 144 watts.

50 watts requires about 4 amps at 12 volts.

Best you go have a look at a high school Physics book !!!

It is correct that there will be a small number of ignitions on cold WVO and that is far from good. Its better than having cold WVO from the line, IP, etc. going through the injector.
We are talking about a system that is in time is going to damage the motor, I think Oliver is just trying to maximize the time until that happens.

Olivier · #23 11-21-2010, 02:06 PM

Finally,
I found the picture of me old system as I said to Layback I try to retreive some.
It was really nice/ compact.
Sold it as I needed some money and I also thought it was not any longer needed

The bother is that once the engine push the coolant into it it just freezed it up as the block is small and 2 glows will never be able to heat up 5 litres of coolant... But it did helped a bit on freezeng start .
Olivier
oh, there is another there and I couldn't uploaded it...
http://www.peachparts.com/shopforum/showthread.php?t=243380

scottmcphee · #24 11-22-2010, 09:46 AM

Layback, that's kind of insulting. Re-read this sentence a few more times:

Quote:

Adding between 25 and 50 Watts of energy to each injector line takes between 12A to 24Amps (drain on the battery).

My car has 6 cylinders. So does the OP.

This is a case of high school language arts for reading comprehension, if I'm not mistakin'

benzhacker · #25 11-22-2010, 07:54 PM

Quote:

Originally Posted by Olivier

Thank you both.
10 PSI highter will be then

145 PSI
What I am putting meself into again

All the best.
Olivier

Correction - 10 bar, not 10 PSI. The factory specs call for 135-145 for a turbo engine, with no more than 5 bar between any two injectors. Most diesel shops can get it within 2-3 bar, though it can take futzing with shims and several attempts to get it right. I always have my injectors at the top of the range and usually find the sweet spot for fuel advance 1-2 degrees above the 25-26 degrees cited in the FSM for the fuel injection timing.

-BH

Olivier · #26 11-29-2010, 01:30 PM

I was suppose to put the injector pressure highter tomorrow but its snowing and its cold, O degres C during the day and minus at night

Injectors are on 125 bars and the car is starting even at those temperature with only a little mix, 0.15% acetone and 1 litre of RUG in about 35 litre of veg. This might be due to the fact that I am on 125 as Alastair was saying and I leave it that way for the moment especially on this weather, I will not be tinkering oustide for a wee while.
Car is running great

All good.
To be continued.