First you should know I installed a "golden Fuel veggie system in my truck" it is installed according to their plumbing diagram but I think I found a problem with it. The return line does not go all the way back to the veggie tank it just tee's off back into the fuel line so when you switch back to diesel whatever veggie oil was in the return line goes into your diesel tank. I have been running the veggie oil for about 2,000 miles with no problem. recentaly the truck started shaking after warming up idling and driving in the lower RPM's. The truck doesn't have near the power that it used to, and it's top speed seems to be around 65-75 mph on flat ground. If I try to give it more gas I see the "fuel reset light" flash for a split second every 5 minutes or so. I can also hear the fuel pump pumping faster light it it has a fuel restriction somewhere. I found at the bottom of the fuel filter there was some crud built up there and I cleaned the bowl out, plus the black plastic part with the spring in it that is in the middle of the bowl. I looked at the manual about the fuel reset light and it seems to be in case of an accident it shuts off power to the fuel pump and that is it. It doesn't have anything saying why it would flash. Things I have tried so far:
changing the fuel filter..
changing the oil to synthetic amsoil diesel oil.
I have been running just diesel in the truck for the last 1,000 miles with the same results.

1999 SD 7.3 PSD 4 door long bed 8" lift 38" tires (it has a superchip installed by the previous owner but it runs the same chipped or back to stock)

 

Can you tell us a little more info? Smoke on start up? Hard Start? Where are you located (climate)? How are you filtering/dewatering your wvo?

 

no smoke on startup or when driving (except when I forget to purge the WVO I have white smoke), no hard start except for when I leave it overnight in the snow, or forgetting to purge (I have gone to the snow once and forgot to purge every so often). I haven't run veggie oil for a month or so now. I live in california, the bay area. I settle the solids and water out of the WVO with a water heater and filter it through a 2 micron luber finer filter. I also have a 12 micron filter on the truck before it goes to the stock 14 micron filter. I also don't drive the truck everyday sometimes I let it sit for a week between driving it. I am working on a centrifuge but that project got put off as I was moving and haven't started it again.

 

Thanks - here are a few possibilities. It may not be a veggie problem at all - it may be an electrical gremlin/short with your emergency fuel shut off valve. It could be your under valve cover harness etc. . . . Not purging at all or even doing it incompletely opens you up to a huge variety of negative consequences. These consequences will be exacerbated with less than frequent driving. I'm sure you're familiar with polymerization - well imagine what that does to your very sensitive injectors - also consider how it can impact your ICP and IPR - if you don't purge properly, then fire up your truck several days later chances are pretty good you're blowing some of that polymerized wvo into your oil at start up (blow by). Here's the thing - I'm not an expert - but many folks here are very good at diagnosis - and usually they will suggest getting your codes read and coming back with that info to determine a starting point. BTW- how did your oil look when you changed it?

 

Seems screwy to pollute your dino fuel with veggie oil. Eventually, the dino will have a lot veg oil in it. Not good. I'd be fixing that.....

 

In reply to nunya: I was thinking about takingthe IPR off and cleaning it, I have noticed others having similar problems doing this. the oil looked dark and thick. this is the first oil change I have done on this truck, I put 3K miles on it since I owned it. I thnk this is typical diesel dirty oil. I have 2 mercedes diesels and it looks the same. I am planning on doing the in tank mod also since I probably have to clean out any veggie oil that got in there.

in reply to izzy: I am not using vegi oil again unt I resolve the return problem and the trucks running problem

 

Sounds like a good place to begin. I'd be interested in what your injectors look like too. Take a moment and let us know how it turns out.

 

I'm leaning towards something electrical - possibly CPS? Before I learned how to properly purge the Mercedes, it was sending about a cup of wvo to the diesel tank. After a month or so, cold start ups were starting to be a problem. Since purging correctly, no more hard starts. All the Mercedes guys routinely run the tar out of their engine to make it run better.

 

Yes you definitely do NOT want veg oil in your diesel tank. I recommend that you visit the message boards for frybrid.com and greasecar.com. Both of those forums currently have threads going on this very topic. You have an inferior grease kit. The good news is you CAN improve on the flaws of the GFS kit for PSD's.

 

I tried "sea foam" injector cleaner and a new fuel filter with no luck. I have some free time during x-mas and new years so I will start breaking the truck down and looking at stuff I think starting with the IPR, then maybe the injectors to check the spray pattern. This will be my first time working on a diesel, I am very mechanical but have worked on gas all my life, it is something I got from my parents hating diesels. but now that is all I drive. 96 E300, 83 300TD & 99 PSD of course.

 

First off, I'm sorry your having troubles with your truck. That sucks! Second, I am not a scientist, salesman, or advocate, I'm just going to put out my 2cents. I have taken several coarses at the local tech college, and gone to countless semonars on wvo and biodiesel. I would be concerned with your injectors. Wvo is a triglyceride (spelling?). It's molecules have a very different shape than petro diesel. The instructors have been playing with this stuff for years, and had samples to back their warnings. They showed us clogged injectors from wvo. They looked like they were dipped in carmel. Then he showed us injectors run with biofuel. They looked super clean. These engines were run in a controlled environment for hours and hours (dyno cell).
I did attend a semonar where they sang praises of wvo. They were selling the kits. They did admit that fouling was more common, but the cost savings in fuel would offset the replacement parts over time. Didn't sound good to me.
Triglycerides are bad for us too. They clog arteries, why not injectors? The process of transesterification converts wvo to boifuel. Tri to monoglycerides. It is a chemical change that makes the shape of the molecules much closer to petro diesel. That's what all those processors do. I would take the time to process your fuel, if you have time and space for it.
Sorry this is getting long. I think your truck may have had fuel system issues before that were not so noticable, but were compounded by the wvo. Too bad. Again just my 2cents. Good luck. Denny

 

I was on my way to work today with this truck and it drove about 30 miles with the same symptoms described above then it slowly died on me. I was running off of diesel and there was a little less than 1/4 tank. I can get it started again but it won't run well enough to drive. A buddy told me he thinks my injection pump is going out but I haven't talked to any professionals. I tried adding 4 gallons of gas but nothing changed.

 

PosSibly an air leak.

 

What's the fuel pressure reading? How much vacuum before the fuel pump?

 

I disagree that allowing vo to get into the diesel tank is a bad condition.
I do suspect there is a problem with the fuel system.
Eric is right. What fuel pressures are you getting at the fuel bowl. If you do not have at least one pressure gauge, you need to install it.
I utilize my gauge as a filter and regulator monitor.

Check my signature.