Doesnt start on Deisel but dies on WVO??? - PeachParts Mercedes-Benz Forum

Astroman · #1 02-01-2009, 12:24 PM

Quote:

Originally Posted by NC Benz

We actually have a problem with the RPM being LOWER, where we need to keep our foot on the accelerator until it warms up.

I am still barking up the air leaks tree with this too.

Right, until the car warms up enough for the idle to be high enough. I stand by my diagnosis.

NC Benz · #2 02-01-2009, 03:17 PM

Quote:

Originally Posted by Astroman

Right, until the car warms up enough for the idle to be high enough. I stand by my diagnosis.

The only problem is that it will start WARM on Diesel. It will not start COLD with diesel. But will start cold when we add a little VO.

Wouldnt that negate the plunger issue then?

Just to make sure.... I am NOT arguing, just trying to understand.

turbobenz · #3 02-01-2009, 03:46 PM

I agree to the second poster, you probably destroyed your plungers with the VO.

Or your timings off and the slower combustion or flash point gets it started

jross · #4 02-01-2009, 03:58 PM

Your symptoms are pretty close to what happened with my car when the IP burned out because of WVO (whoever did the install before I bought it didn't install a sufficient WVO heater).

Bummer, man. The good news is IPs are pretty easy to do if you don't mind getting a bit oily. The hard part is finding one that doesn't cost an arm and a leg...

Astroman · #5 02-02-2009, 10:26 AM

Have you tried just priming the heck out of it before you attempt the first cold start? Just on plain diesel fuel, prime it like crazy, then try starting. The only other thing I can think of is air leaks in the system. Then when that doesn't work, replace the IP..

NC Benz · #6 03-21-2009, 04:50 PM

I am able to finalize this issue.

It turned out it was not the plunger, but it was a hairline crack on one of the return lines that was sucking in air. Once it was found and replace (we replaced all of the lines) it started just fine.

Alastair · #7 03-21-2009, 05:15 PM

Quote:

Originally Posted by jross

Your symptoms are pretty close to what happened with my car when the IP burned out because of WVO (whoever did the install before I bought it didn't install a sufficient WVO heater).
leg...

Nah, Heat-Exchangers or the Lack of them will NOT cause issues with the pump when using veggy-oil...

What does, is cruddy, dirty, moisture laden, FFA Loaded, over-used and poorly prepared Used/Waste Vegetable-oil, or WVO....

The biggest killer in Used VO is the Moisture which Cant be filtered out and the second is the FFA which turns the moisture Acidic...

(FFA is, Free-Fatty-Acid. This is an oil just like the veggy its dissolved in. It Cannot be Filtered out. It is not a heavier component like fats)

Leaving the WVO to stand will NOT remove all the moisture from it. It MUST be Dried Properly, by heating up to 120 deg C with lots of air contact regardless of what others say....

The metal of the elements (plunger/barrel assy.) inside the pump is hardened Steel. Acidic moisture in WVO just Loves to munch on those precision parts making them a dull grey 'pickled' appearance and increasing clearances. They are normally a Mirror-finish, just like the needles of new injectors....

My Diag, FWIW is the I.P. Elements destroyed by cruddy, and damp WVO.....