BioDiesel Problems, I think...

[dhmarkley]

I have just started running b100 in my 95 gmc 6.5L and it hasn't been going good. I have been running b100 in my VW and Isuzu for years with nothing but success. The problem i have dealing with is that after i run the bio for a couple of weeks, the ip goes out. It usually starts with a slight stutter under acceleration and then out of the blue the truck will start and stall right away. The only way i can get it to run is to unhook the CPS and put the truck into limp mode. After running in limp mode for a little, i can turn it off and hook the CPS back up and it will start and run like normal for a while. I have replaced the original ip with a replacement and then had to replace the replacement with a replacement. I am at a loss on what else to do. Here is what i have tried so far. Replaced IP (and PMD) Replaced oil pressure switch Replaced injectors Replaced IP again after failure (Also dropped the tank and cleaned out the fuel lines. Checked lift pump for operation The fuel i am using is crystal clear and has been running in my other diesels with no problems. Does anyone have any suggestions for me? Thanks Derek

[More Power]

Is the fuel dislodging crud in the fuel tank, which plugs the fuel filter? I've read where bio can act as more of a solvent, which then loosens anything (crud) coating the inside of the fuel tank and fuel system.

Does the fuel cause rusting/corrosion of the steel components inside the fuel injection pump?

If the answers to both are "no", there shouldn't be a problem.

Jim

[joe bleaux]

I burn w.v.o. in my Mercedes 300SD and it ran fine when I first started using it and after about a month, it dissolved crud in the tank and the old rubber fuel hoses. Cleaned the tank and replaced the short rubber hoses. All is well.

Joe





Is the fuel dislodging crud in the fuel tank, which plugs the fuel filter? I've read where bio can act as more of a solvent, which then loosens anything (crud) coating the inside of the fuel tank and fuel system.

Does the fuel cause rusting/corrosion of the steel components inside the fuel injection pump?

If the answers to both are "no", there shouldn't be a problem.

Jim

[dhmarkley]

Is the fuel dislodging crud in the fuel tank, which plugs the fuel filter? I've read where bio can act as more of a solvent, which then loosens anything (crud) coating the inside of the fuel tank and fuel system.

Does the fuel cause rusting/corrosion of the steel components inside the fuel injection pump?

If the answers to both are "no", there shouldn't be a problem.

Jim

The answer would be yes and no. The bio does loosen the gunk that has been built up in the tank and ip, but the tank has been dropped and the ip replaced since i have started running bio.

The fuel does NOT cause rusting or corrosion.

[JohnC]

When you say "CPS" do you mean "Crank Position Sensor"? If so, it's bad; replace it. If you mean the optical sensor in the pump, well, I don't know why that would happen unless the bio diesel is cloudy.

[dhmarkley]

When you say "CPS" do you mean "Crank Position Sensor"? If so, it's bad; replace it. If you mean the optical sensor in the pump, well, I don't know why that would happen unless the bio diesel is cloudy.

CPS = Crank Position Sensor

I have replaced it twice. Once with an auto parts replace the second one (curently in the truck) Is a GM OEM replacement.

[dhmarkley]

I just got back from a trip down to my buddy's house and back so i could see if changing the timing would do anything. The truck has a little more pep in it's step, but on the way back it shut of again. Back to the drawing board i guess.

[convert2diesel]

I know you said that the bio was clear but have you tested it for complete reaction. Your VW and Isuzu may very well be more tolerant of partially reacted oil.

I have made some great looking fuel that turned out to be only partially reacted or when I tried to boil off the excess methanol, the reaction actually reversed itself. The resultant fuel came out looking clear and washed out fine but a 3/27 test revealed it was only partially reacted.

The higher viscosity and or the opacity may be causing your problems. A number of guys over on the bio-diesel board have complained of the electronic Stanadyne being overly sensitive to less then ASTM grade fuel.

Even if you are buying from a commercial vendor, do a few tests. Have run across some really skanky stuff that looked great. Part of the overall problem in getting this stuff accepted by the general public. There was a reason for the ASTM standards.

Either way, the older mechanical IPs were much more tolerant.

Bill

[jeffscarstrucks]

I am not trying to high jack this but can you tell me where the bio diesel board is? I think my son is about to push me in this direction and I need to school up pretty fast. Thanks, Jeff
P.S. I am thinking it is another forum other than this one....

[dhmarkley]

I am not trying to high jack this but can you tell me where the bio diesel board is? I think my son is about to push me in this direction and I need to school up pretty fast. Thanks, Jeff
P.S. I am thinking it is another forum other than this one....

Kudos to your son! Biodiesel will be a big part of the energy revolution. (My modest opinion) That aside http://biodiesel.infopop.cc is one of the best resources i know of. Grahm laming http://www.graham-laming.com is also a very good resource on biodiesel. The GL Eco-system processor is definately worth a look.

The most important thing is to have fun with it! You are saving the enviroment and some cash (.70/gal vrs 4.89/gal) all at the same time.

Good luck!
Derek

[dhmarkley]

I know you said that the bio was clear but have you tested it for complete reaction. Your VW and Isuzu may very well be more tolerant of partially reacted oil.

I have made some great looking fuel that turned out to be only partially reacted or when I tried to boil off the excess methanol, the reaction actually reversed itself. The resultant fuel came out looking clear and washed out fine but a 3/27 test revealed it was only partially reacted.

The higher viscosity and or the opacity may be causing your problems. A number of guys over on the bio-diesel board have complained of the electronic Stanadyne being overly sensitive to less then ASTM grade fuel.

Even if you are buying from a commercial vendor, do a few tests. Have run across some really skanky stuff that looked great. Part of the overall problem in getting this stuff accepted by the general public. There was a reason for the ASTM standards.

Either way, the older mechanical IPs were much more tolerant.

Bill

Thanks Bill for your input! I haven't done the 3/27 test on my fuel yet, but it will be something i will be doing tomorow! I have always figured that if it looks good and it runs good it must be good... That logic seems to only to work with older manual injection systems. I will run the tests tomorow and post my results.

Thanks again
Derek

[convert2diesel]

Kudos to your son! Biodiesel will be a big part of the energy revolution. (My modest opinion) That aside http://biodiesel.infopop.cc is one of the best resources i know of. Grahm laming http://www.graham-laming.com is also a very good resource on biodiesel. The GL Eco-system processor is definately worth a look.

Again, lets not highjack Derek's thread but to those who are interested, the infopop site is probably the most comprehensive site to research bio-diesel. The set up of the site is horrendous but if you set aside a few hours (and at least two pots of coffee) this site will supply you with all the information needed to get started and for most part, the people on it will bend over backwards to help you on your quest.

Derek:

Another thing you might try is to work up your bio concentrations in stages, starting with B20, and increase untill your problem starts again. It could be possible that the guts of your IP are just too sensitive for B100. By far the most effective way of getting around your problem would be to do the 4911 mechanical pump conversion (do the search..it's on here somewhere).

Bill

[dhmarkley]

Derek:

Another thing you might try is to work up your bio concentrations in stages, starting with B20, and increase untill your problem starts again. It could be possible that the guts of your IP are just too sensitive for B100. By far the most effective way of getting around your problem would be to do the 4911 mechanical pump conversion (do the search..it's on here somewhere).

Bill

Bill,

Well it looks like i am going to be switching over to a manual pump. I just did the 3/27 test on my last 5 batches (I keep a little from each for QC) and they all test good. No drop out.

I did a search for the mech pump conv. and i find alot of post talking about it, but i haven't beenable to find the post that tells you how to do it.

Now all i have to do is find someone that has some parts laying around.

Thanks again!
Derek

[JohnC]

If it runs with the CPS unplugged then the problem is not with the pump. When the CPS is unplugged it runs off the optical sensor in the pump. If that were the problem, it would not run at all (unless You unplugged the optical sensor instead). Of course, eliminating the electronic pump eliminates the CPS too. If you have a 5 speed, the conversion is a lot simpler.

The conversion is not trivial. You have to trick the auto trans and add your own cruise control (or do with out), for starters. There have been articles written on how to do it in the membership section of the web site, and one member published a booklet on his efforts. Not something easily covered in a forum thread, though.

I have a mechanical throttle pedal I'll sell you to get you started! ;)

[dhmarkley]

If it runs with the CPS unplugged then the problem is not with the pump. When the CPS is unplugged it runs off the optical sensor in the pump. If that were the problem, it would not run at all (unless You unplugged the optical sensor instead). Of course, eliminating the electronic pump eliminates the CPS too. If you have a 5 speed, the conversion is a lot simpler.

The conversion is not trivial. You have to trick the auto trans and add your own cruise control (or do with out), for starters. There have been articles written on how to do it in the membership section of the web site, and one member published a booklet on his efforts. Not something easily covered in a forum thread, though.

I have a mechanical throttle pedal I'll sell you to get you started! ;)

This is the reason i have been frustrated working on this. Everything i know points to the OS, but like you said, If the optical Sensor was bad the truck would not run without the CPS. So if it isn't the OS or the CPS then what could it be? :confused:

Can the truck run without the CPS? Or should i say should it be able to be ran without the CPS, relying only on the OS? I would think it would send the truck into my all favorite limp mode.

[AKMark]

I have a real good mechanical pump if you need it.

[convert2diesel]

Derek:

The physical change over is not complicated and for the most part, is just bolt on:

1. 4911 pump (there were some other big bore pumps used on commercial chassis...will try to get the number off the side of mine)

2. You will need the aforementioned throttle pedal and the throttle cable bracket from a mechanical pump. If you don't need cruise, get a throttle cable from any of the pre-93 trucks. If you want the cruise, see if you can find a 94-96 Cadillac Fleetwood with the LT1 engine and traction control. They have a neet little spool that mounts under the hood that both the cruise control cable and the throttle cable goes into. From the spool a single cable goes to the pump. The spool was used to kick off the throttle when traction control kicked in...just keep it unplugged. Great arrangement using stock GM ends. Note you will also have to get the cruise control module off same car or any RWD GM of the same vintage. These units are electronic not vacuum and will wire directly into your cruise switches and the VSS.

3. Miscellaneous fuel line adaptations to suit.

The electronic tranny control is another issue. During the early nineties, GM used the 4l80e and the 4l60e coupled to non-electronic engines, specifically the "C" chassis (van conversion) and other commercial applications. They used a stand-alone transmission controller (usually mounted under the drivers seat). Don't know the part number but being OBD1, it will require both the box and the chip (an aftermarket box won't have the chip). If you can find one in the junk yards, get the harness from it as well and take note of the model and serial of the donner vehicle. You will need the wiring diagrams for both your truck and the donner truck to get everything talking to each other.

This controller uses the hall effect throttle plate location sensor and I believe a tach signal to control the tranny.

Another avenue is getting someone in the know to re-program your current ECM to ignore all the engine related functions that are not needed for the tranny. PCMforless is working on this project but I don't know how far they have progressed. Being OBD1 may be an issue.

Going through the same thought process for my next conversion. A 94 Cadillac Fleetwood with the 4l60E. Going to be installing a 6.5 turbo but with the mechanical pump.

I have not done one of these conversions yet but the above is based upon the research to date and is subject to change (sometimes daily). Let me know how you get along.

Bill

[dhmarkley]

I have a real good mechanical pump if you need it.

I might be intrested. Let me know how much you want for it.
E-Mail
(derek@dhmarkley.com)

[dhmarkley]

Derek:

The physical change over is not complicated and for the most part, is just bolt on:

1. 4911 pump (there were some other big bore pumps used on commercial chassis...will try to get the number off the side of mine)

2. You will need the aforementioned throttle pedal and the throttle cable bracket from a mechanical pump. If you don't need cruise, get a throttle cable from any of the pre-93 trucks. If you want the cruise, see if you can find a 94-96 Cadillac Fleetwood with the LT1 engine and traction control. They have a neet little spool that mounts under the hood that both the cruise control cable and the throttle cable goes into. From the spool a single cable goes to the pump. The spool was used to kick off the throttle when traction control kicked in...just keep it unplugged. Great arrangement using stock GM ends. Note you will also have to get the cruise control module off same car or any RWD GM of the same vintage. These units are electronic not vacuum and will wire directly into your cruise switches and the VSS.

3. Miscellaneous fuel line adaptations to suit.

The electronic tranny control is another issue. During the early nineties, GM used the 4l80e and the 4l60e coupled to non-electronic engines, specifically the "C" chassis (van conversion) and other commercial applications. They used a stand-alone transmission controller (usually mounted under the drivers seat). Don't know the part number but being OBD1, it will require both the box and the chip (an aftermarket box won't have the chip). If you can find one in the junk yards, get the harness from it as well and take note of the model and serial of the donner vehicle. You will need the wiring diagrams for both your truck and the donner truck to get everything talking to each other.

This controller uses the hall effect throttle plate location sensor and I believe a tach signal to control the tranny.

Another avenue is getting someone in the know to re-program your current ECM to ignore all the engine related functions that are not needed for the tranny. PCMforless is working on this project but I don't know how far they have progressed. Being OBD1 may be an issue.

Going through the same thought process for my next conversion. A 94 Cadillac Fleetwood with the 4l60E. Going to be installing a 6.5 turbo but with the mechanical pump.

I have not done one of these conversions yet but the above is based upon the research to date and is subject to change (sometimes daily). Let me know how you get along.

Bill

Thanks for all of the info. One nice thing is that i have the 5spd Man Trans. It does have cruise, but i can deal with not having it for now.

[dhmarkley]

I have a mechanical throttle pedal I'll sell you to get you started! ;)

How much?
E-Mail
(derek@dhmarkley.com)

[convert2diesel]

Derek:

Will try to post a picture of that Caddy spool system. It is probable that a number of the high end GMs of the era would share the same system. That would allow you to use the cruise module. All it really needs is a vss input (same as your speedo input). Fifty bucks and your done.

I would do the conversion but keep the ECM in place. Just disconnect the throttle input and any of the pump related connectors, hot wire a fuel shut-off and cold start advance (see wiring for pre-93 trucks) and see what doesn't work.

You might confuse the poor computer thingy and for sure you will get a check engine light but if everything else works, who cares. If you don't need the tranny controls, I can't see a down side. Your AC may be a little wonky but I can't think of anything else that would be effected. Don't know how they are configured in the trucks, but all instruments should still work even if the puter is in full deault. If all goes well, then do a CEL delete (disassemble dash, remove light bulb, reassemble dash and drive screw driver through buzzer if equipped).

Bill

[arveetek]

For whatever it's worth, I've been running home-brewed biodiesel in my '95 6.5L for two years now, and I haven't experienced any problems, other than an FSD failure, which is not fuel-related.

Casey

[dhmarkley]

For whatever it's worth, I've been running home-brewed biodiesel in my '95 6.5L for two years now, and I haven't experienced any problems, other than an FSD failure, which is not fuel-related.

Casey

I don't know what is going on with this truck anymore. I'm thinking that it might be a PMD going out, but this PMD has only been in the truck for about 6 months or so. It is still mounted on the pump because the pump is still under warranty and i can't move it or i will void the warranty. FSD? Is that the same thing as the PMD? Fuel System Driver - Pump Mounted Driver. For the last 3 days the truck has been behaving itself but i guess only time will tell.

Thanks for the info, it is a little comfort knowing that their is someone else rinning b100 without any problems.

Do you do a water wash or do you settle?

[arveetek]

I don't know what is going on with this truck anymore. I'm thinking that it might be a PMD going out, but this PMD has only been in the truck for about 6 months or so. It is still mounted on the pump because the pump is still under warranty and i can't move it or i will void the warranty. FSD? Is that the same thing as the PMD? Fuel System Driver - Pump Mounted Driver. For the last 3 days the truck has been behaving itself but i guess only time will tell.

Thanks for the info, it is a little comfort knowing that their is someone else rinning b100 without any problems.

Do you do a water wash or do you settle?


Yes, the FSD and PMD are the same animal. And it's not unusual for a PMD still mounted to the pump to fail again. They are very finicky pieces of equipment.

I water-wash and then dry the fuel. My equipment is all home-made using the appleseed reactor plans found on the net.

Casey

[dhmarkley]

Well the truck was working pretty good for almost 3 days, then it all went down hill fast. I am going to try to attach 3 pics of my code reader software that show the codes i have been getting.