Biomass based diesel vs biodiesel - Page 4 - PeachParts Mercedes-Benz Forum

sleepstar · #46 03-24-2015, 10:28 PM

i've run nothing but B20 to B100 since owning the car...does that mean you think the station is the one with the issues? The 76 on university is pretty much equidistant for me so maybe i should try filling up there next time...

otto huber · #47 03-26-2015, 03:33 PM

I went to the Berkeley station the other day and put in 11 gallons. The idle still isn't as good as it was before using HPR, so I'm thinking that maybe my engine just isn't as happy with this stuff as it is with a biodiesel/D2 blend. I'm hoping that I can run at least a 50/50 blend of HPR and D2 in the future with good results.

renaissanceman · #48 03-26-2015, 03:37 PM

Interesting. Since Propel introduced HPR, the only place to get B20 in Fresno is (most likely) gone...sad day.

tjts1 · #49 03-26-2015, 03:46 PM

By all practical measures, HPR is a superior fuel to B20.

otto huber · #50 03-26-2015, 04:05 PM

Quote:

Originally Posted by renaissanceman

Interesting. Since Propel introduced HPR, the only place to get B20 in Fresno is (most likely) gone...sad day.

There's a place in Berkeley that sells B99. If the fuel wasn't so expensive($4.89/gallon), I'd buy more. I usually put a few gallons in the tank, fill up a carboy and then add some B99 at home after filling up with D2.

renaissanceman · #51 03-26-2015, 04:24 PM

Quote:

Originally Posted by tjts1

By all practical measures, HPR is a superior fuel to B20.

Right, it just doesn't provide the lubricity that we need.

RunningTooHot · #52 03-26-2015, 05:30 PM

I'm back up in the bay area for the next few weeks, and I once again filled up with the HPR. I continue to be VERY impressed with how good this fuel is.

I've got one glow plug that's non-functional, and with regular D2 that cylinder misfires a bit during cold starts and then nails slightly until the engine has warmed up for about 30-45 seconds or so.

With the HPR, it fires right up with maybe two or three misfires, then after no more than 5 seconds, it's completely smooth with no nailing whatsoever. I attribute that to the HPR's extraordinarily high cetane rating. I always take it easy on a cold engine anyways, but when running HPR a cold engine runs much better than on D2 - it runs almost like it's already been warmed up, with none of the typical cold diesel rigor mortis.

If there are concerns about lubricity, just add whatever flavor of your favorite additive that you like. I run Power Service, which is redundant because HPR obviously doesn't need the cetane boost, but it's what I have in the trunk.

Quote from their website:"Diesel HPR meets the ASTM D975 diesel specification (ULSD) for use in all diesel engines." I don't necessarily like "minimum" anything, so maybe I'll pick up some low ash two-stroke oil and throw it in the tank just for the heck of it...

renaissanceman · #53 03-26-2015, 05:42 PM

I wonder if the older diesels have more issues than the more modern 60x.xx engines. I'm definitely going to fill my '87 300D up in Sac in a couple weeks when I drive the I-5 corridor to CA.

otto huber · #54 04-02-2015, 02:24 PM

I now have a serious fuel leak coming from the lift pump where the clear fuel line connects. Do I have to replace the entire line, or is there a gasket that goes there?

otto huber · #55 04-02-2015, 05:51 PM

Upon further inspection it looks like the leak is coming from the clear line that goes from the filter housing to the injection pump. It's leaking at the pump. Hopefully this is the only spot that there is a leak.

sleepstar · #56 04-02-2015, 09:49 PM

those clear plastic lines are very prone to cracking and leaking especially if they're original.
this video explains the problem and offers an easy solution:
https://www.youtube.com/watch?v=iJLw4nwqfcY

otto huber · #57 04-03-2015, 02:03 AM

By tightening the 17mm banjo bolt on the IP, I was able to reduce the leak substantially. Hopefully it's just a washer that needs replacing.

otto huber · #58 04-04-2015, 01:35 AM

Replacing the washer at the IP did the trick. I didn't want to side track the thread, but make it clear whether or not my issue was related to HPR. It must have been a coincidence because I can't see how a metal washer would have been affected by fuel. It also looked as if the washer that failed was the wrong size.

renaissanceman · #59 04-05-2015, 01:32 AM

I just filled up with HPR today in Fresno. I met a gentleman driving a VW toureg diesel, and he had nothing but great things to day about it -- he claims +2 mpg and absolutely no smoke when starting cold.

I noticed a very smooth idle after 15 miles or so of highway driving. I put in 16oz of TC-W3 2-stroke oil for added insurance against poor lubricity (may not have needed to, if Propel's lubricity claims are true), to which the VW man said "I've heard of people doing that, but never seen it. That's brave of you".

We'll see how she starts in the morning. I've got a dead #4 glow plug that I haven't fixed yet, which usually results in 10 seconds of crappy idling when started cold.

BillGrissom · #60 04-06-2015, 03:09 PM

I'll amend post #37. I don't think the leaking hose (lift pump to main fuel filter) was due to Diesel HPR. It was fairly hard when I removed it, whereas I read that bio typically softens rubber hoses. I couldn't read the numbers, probably generic 1/4" fuel/emissions hose I used to replace the factory nylon hose when it cracked. Anyway, I replaced it w/ 1/4" Barricade hose from NAPA ($4/ft) w/ label "bio-diesel" (or such).

Before that, I bought 1/4" PEX tube (3/8" OD) at Home Depot, but they didn't have clamps for it. I since bought a bag of 3/8" ID 1-ear clamps (Otiker-style, stainless) on ebay, so I may try PEX on the next hose.

I was planning to pull the screen on the fuel tank outlet, but I notice no debris in the pre-filter and the engine runs fine, so no sense fooling with that.

Just filled up yesterday w/ HPR ($2.69/gal). 10c less than regular diesel and 20c less than unleaded gas. After years suffering with higher prices for diesel I am sitting pretty. The engine definitely idles quieter on HPR and runs better when cold.