I changed my fuel filter @ 2 weeks ago due to the feel of fuel starvation upon hard acceleration. It resolved the problem too.
I got on it again yesterday and lo and behold, feels like fuel starvation AGAIN. I took it to the stealer and they hooked up the tech 2 and showed some old minor codes but nothing acute. He then hooked up the vacuum monitor for the fuel and it showed @ 6 at idle. He said 3 is normal. WHAT gives? THEY recomended GM fuel filter but I said they are too much!
I am running premium diesel and adding biodiesel at @ B15- 20. Yesterday I decided to run straight Biodiesel for a few miles to clean everything out. Any other ideas?

Ben

Sounds like your biodiesel may not be very clean...

Sounds like your biodiesel may not be very clean...
I did not even think that. I thought that maybe it is cleaning the crud out of the fuel system. I might just run straight Bio for now and use it all up, then change fuel filters.

Ben

Based on my personal experience, 6" vacum would not cause fuel starvation. I have seen as high as 22" before light came on.

blnagel,

Can you change the filter and cut it open and see what is plugging it.

IF the bio was that dirty you could probably see the crud in it as you pour in your tank. Or at least look at the bio in a clear container.

If the bio is clear...then maybe you are indeed cleaning out your tank.

The OEM filter is the same no matter where you buy it..so not sure what the dealer meant.

My bet would be the solvent power of the biodiesel is cleaning your fuel system. You see this sort of thing happening all the time with new biodiesel users. That being said, you do need to make sure your biodiesel source is selling spec fuel and is keeping it clean.

What should it look like in a clear bottle? It pours easily. I will run straight Bio and then change fuel filter just in case it is "cleaning" the fuel system. I will cut open.

I did ask about the fuel regulation valve and the tech said these rarely go out. Would that be a/the problem?

Ben

Bugs in the tank. Bio really makes them grow.

Greg

Bugs in the tank. Bio really makes them grow.

GregWhat should I do if that is the problem?
I dont have access to much stuff around here. I am able to get Diesel Kleen, Stanadyne.

Ben

I think LanduytG Is messing with you!

I think LanduytG Is messing with you!

No I am not messing with you. I sounds like a case of bugs. It can get bad enough to plug filters very quick. You can a biocide. I have it and i am sure George Morrison at AV Lube does to.

Greg

Would Diesel Kleen help? I need to get this fixed soon. As I am going on a trip shortly.

Did youn try draining the filter and see whatb the stuff looks like in a jar.

Standyne is good additive.Wiith biodiesel you might want to double up on the cetane additive and see if that helps. Suspect your using fuel with a very low cetane rating and I doubt if you can find out what it is. My guess would be that its less than 40. You might ask your dealer what it is and iif he doesn't know, ask the distributor. Haven't found a distributor here in San Antonio that wants to tell me when I ask them so I suspect its quite low.

I have not drained it as yet. How do I do that? Do I need to remove the filter itself and remove the bottom?

Ben, you should listen to these guys and get some biocide, any Napa should have it.

Chipper, what kind of vacuum gauge you using? Would it be inches of water? You do know that an industrial vacuum pump will only pull 27 inhg at our altitude? Later! Frank

Bio is normally high cetane. Regular fuel additives will not kill bugs it takes a biocide to do that. I was not aware that NAPA carried biocide. But something like this is what you need. Primrose Biocide (http://www.lubricationspecialistllc.com/product_info.php?cPath=39&products_id=174)
Greg

If you do in fact have any bugs growing that fast you are not going to cure the plugging filter problem. They will still be there plugging everything up until you clean the tank. Later! Frank

I will check with NAPA in AM but if not then I can get my hands on FPPF killem in the next 2 days.

WOW this is seeming like it is a PAIN in the keester.

Ben

Traditional additives WON"T work with Biodiesel. You must use the ones specific to biodiesel. If fact, I have been told NOT TO USE traditional additives with biodiesel.:badidea:

Anti-gel additives may not have the same effect with bio, but cetane improvers would work just fine. Biodiesel is chemically miscible with petrol diesel fuel and anything that mixes with petrol diesel will mix with bio.

Good call on the bugs, Greg, I didn't even think of that. Ben, if you are buying biodiesel in bulk and mixing it yourself, you should also treat your storage containers with biocide as well. Dirty storage containers are a good way to get contamination into your fuel system.

i have a question for you guys. when you store your fuel at home or wherever do you filter it before it goes into your truck? like from the pump? this might save changing them on the truck all of the time.

Sounds like it's also time for your own filter restriction gauge so YOU can gauge what is normal, and what is not. Then some improved filtration, preferrably BEFORE it hits your tank...

i have a question for you guys. when you store your fuel at home or wherever do you filter it before it goes into your truck? like from the pump? this might save changing them on the truck all of the time.
I would think any kind of permanent home storage tank should have at least a filter and better yet a water separating filter on the output.

It is not a great picture but the filter is only 3 weeks old and I think looks good. WHAT gives? Maybe a poor filter?

Ben

If it were bugs that thing would be black. But it still would not hurt to treat it for bugs.

Greg

I have not drained it as yet. How do I do that? Do I need to remove the filter itself and remove the bottom?
Assuming yours is the same as my 03, there's a valvle on the bottom of the filter. I put a piece of clear palastic hose on nthis valve and drain it into a jar on the ground. This takes about 3- 3 1/2 ft of tubing and saves makking a mess. You have to open the bleeder valve by the pump on tkiop of the filter,, this willk release the vacuum and let the fuel flow easily. When fuel flow stiops, close the valve firmly and then operate the pump until fule comes out of a hole in the bledere valve, At thios point close the bleeder valve and remove the hose and jar. To save on making a mess, wrap an old rag around the bleeder valve area to catch the fuel that squirts out of the bleeder valve hoilke when the filter gets full. GOOD LUCK.:)

No bugs on that filter. Later! Frank

Anything in the electronics that would screw up? Air filter? Transmission slipping?

The above are guesses.

Air filter looks fairly good. Not too old. I already have the Suncoast III. Would the fuel regulation valve do it?

I did get on it yesterday and it pulled hard with a new fuel filter!

Ben

I use bio all the time, no additives necessary, great lubricity and its way cheaper than commercial additives ....but it will gel readily if its cold enough ....especially if you keep it in a jerry jug outside.
My only source is B100 so I tend to cut it depending on expected temperatures. I've not had a problem so far.
I use B100 straight in to about 50% dilution with No.2 diesel... wintertime I cut back.


Richard

I think it's those new wheels you got Ben, they're just too hard to turn...

Seriously though, that filter looks pretty good to me, I can't see how it would be restricted unless a big chunk of crap covered several of the holes or something. Maybe the bio has made something cruddy come loose in your tank and it is partially over the pickup tube?

Is it safe to run bio-diesel in the duramax diesel engine? I'm all for using
alternate fuels, to reduce our dependence on that dang mid-east oil! The
nearest place for us to buy bio-diesel is about 50 miles away. But, maybe if
more people started using it, more stations would offer it!

Fuel cap vent plugged?

Thats a good thought.....

Running well now.

Ben