Question About Mo

[RoGrrr]

96 7.3 PSD, 5 inch exhaust stacks with no restrictions
I'm running my truck on filtered straight WMO (with no preheating) and I'm experiencing strange things happening in my new experience on MO.
I filtered to 5 microns and poured into my auxiliary tank. I can easily switch between WMO and diesel fuel.
On diesel fuel I've seen that the EGT runs 700 - 800 degrees while cruising on fairly flat freeways with the temps climbing to over 1000 when pulling a hill. I haven't pulled a load enough to be able to speak about those temps.
When I first experienced loss of power, I changed the fuel filter and the truck accelerated normally up past 75MPH when I romped it. But then the loss of power returned.
What I'm finding is that when I run it on MO, the engine loses power and even stalls when running on MO. What I find is that mornings when starting cold I can drive anywhere to 25 to 35 miles before the engine starts to bog down and lose power. I then switch to straight diesel fuel (with the engine still running) and it immediately runs normally. The engine temps run a bit higher than normal - about 800 and climbs to 1100 when pulling a grade or long acceleration.
Afternoons, after work, I make the attempt to drive back home on MO. The truck starts normally and all seems well as I drive thru about 15 minutes of city traffic and get on the freeway. However, in almost exactly the same spot (level freeway) the engine bogs and won't accelerate so I have to pull off the road and switch it back to diesel fuel. I've also noticed the EGT is running about 800 - 1000. Even after I switch back to diesel fuel, it still is running what seems abnormlly hot to me. After a few miles, the temps come back down to normal. The water temp never climbs any. It's only the EGT that tells the tale.
I checked the sock filter in the tank for restriction. Clean. I then checked the fuel line from the tank to the changeover valve and found no restriction in it.
My questions to those of you running MO now are:
For those of you running straight MO, did you have any problems when you did it ?
If you're running a blend, what percentage are you running ?
What EGT do you see when running diesel fuel and then, what temps do you see on MO ?

[rockets10510]

these trucks do not like to run 100%wmo. people have ran as high as 75%wmo and 25% diesel. the safe is to run 50/50. i have run 50/50 all the time and have had no problems. works great. i am filtering down to 2 micron.

anthony

[RoGrrr]

Anthony

How did you find your sweet spot ? I'm sure you have experienced 100% ? Otherwise you wouldn't know about it.

I've read posts by others who drive PSDs on 100% and they didn't say anything about having problems.

RoGrrr

[RoGrrr]

I set out on a trip of about 150 miles each way yesterday with the aux tank containing about 25 gallons of oil and 10 gallons of fuel oil. I diluted the RMO with fuel oil bcuz that is what someone gave me when he changed his furnace to a heat pump. He gave me the contents just for hauling it away.
I went about 50 miles and noticed that the EGT was declining from its normal 800-1000 down to around 400 and the engine started running rough. I stopped and changed the valve back to diesel fuel. Ran normal, with EGT back up around 800-1000. I had also been watching the temps climb to around 1200+ on a long pull up hills.
Maybe 25 miles down the road I stopped and changed back to RMO. Things seemed normal, I arrived in the city and drove around a while, making a couple stops. I got back on the hiway and continued my trip and arrived at my destination without any incident. Spent several hours there, allowing the rig to cool down and started on my way again.
I was pulling a flat bed trailer weighing about 1800 pounds and on the return trip I had it loaded with 8 IBCs, each weighing about 100 Lbs and a 150 Lb shelf. Not much weight overall but a fair amount of wind loading. I limited my speed to 60.
The EGT started to decline so I had to switch back to diesel fuel. After a few miles, I was curious and changed back to RMO. All seemed well for about 15 miles and it was losing power, EGT declining and running rough so instead of switching back, I stopped and allowed the engine to idle for a couple minutes and took off again. All seemed normal.
20 miles or so down the road and it happened again so I parked onemore time but it didn’t return to normal. The EGT didn’t climb back up to where it should have been so I had to change back to diesel.
I’m wondering if the fuel pump might be weak so I’ve ordered a digital gauge to install between the pump and engine. I’ve heard the fuel pressure should be around 60 PSI. Correct me if I’m wrong.
I don’t believe I have clogged injectors or the engine would not run normally on DF after it started losing power on RMO. So cross clogged injectors off the list of possibilities.
I also have noticed that my boost has been kinda lethargic. It has been running below 5, tho I can run it up if I get on it, especially going up a hill. But I can hear the turbo whine like it always has, especially with those 5 inch open stacks and the rear window open.

Does anyone have any thoughts on why this is happening ?

[rockets10510]

never ran 100% people on here suggested against it so i just stayed with a 50/50 mix to be on the safe side.

anthony

Originally Posted by RoGrrr

Anthony

How did you find your sweet spot ? I'm sure you have experienced 100% ? Otherwise you wouldn't know about it.

I've read posts by others who drive PSDs on 100% and they didn't say anything about having problems.

RoGrrr

[RoGrrr]

Well, as you should have read, I'm now diluting my oil. I'm looking for answers rather than "should haves". But I have seen those who are running 100%. There's got to be a secret to it and I'm looking for it

I'm also looking for temps - DATA, you know. Without data, we're all lost

Originally Posted by rockets10510

never ran 100% people on here suggested against it so i just stayed with a 50/50 mix to be on the safe side.

anthony