Trapped in Cape Cod

[Eli]

Hey guys,

I'm up in Cape Cod, MA. With my '79 245, with a D24T from an '85 760 in it. I need to get pack to PA in a few days. Like five hundred miles away.

I've been having some problems. Mainly air in my fuel line. It took me a little to figure out, but the car would get progressively slower, until it would eventually stall. I would open the hood when it would be running and having this issue and see the return line full of bubbles, but I wouldn't see air in the feed line.

The more I've dealt with it, it seems there is air in the feed line as well. Which makes sense. I should say there is still the in-tank fuel pump still left over from when this car was a gasser. So it has an electric feed pump, and I have confirmed it is still running, but I am unsure that it is pumping to it's fullest potential. At first I thought it might be a clogged fuel filter, but I changed it a few weeks ago. It is not leaking fuel, except from the injection pump, but that symptom predates theses fueling issues. I have not opened up the fuel tank yet, but there is no change in the problem depending on how full the tank is. This problem does not seem to happen until the car has been driving for awhile. I don't know what that is about.

I just went on a hundred or so mile drive with my friend and it drove fine for the first 60 or so miles, and then started having this issue. I would pull over when this would happen and the car would basically stall out as we were pulling over. I would then have my friend run the in-tank fuel pump and I would open the bleed valve on top of the fuel filter, trying to purge out the air in the system. Then we would try and start the car which would still take some cranking. It got worse and worse until we were stopping every 5 miles, and I didn't think the battery could take that much cranking every few minutes. We eventually gave up and got towed back to the house. The tow truck driver Rob, was awesome and really liked the car.

I should also state that I have been adding a mixture of 85% WVO 15% Gasoline to my tank. Since I have started having this problem I've been trying to run on more diesel then that. Although I do think when I started doing this is about when the problem started happening. I don't understand why air in the fuel line would correlate with this, but you guys tell me.

If you guys wouldn't mind brain storming this problem with me, I'd appreciate it.

Hopefully all this makes sense.

Thanks very much.

-Eli

[v8volvo]

VW diesels don't like WVO. Biodiesel they love, but WVO is a tricky fuel unless you are doing it just right. Using it straight in the tank with a splash of gasoline blended in is not doing it right. You need lots of filtration and lots of heat, and you don't have either of those things unless there is more to your setup than you described in your post.

Start with ensuring it has a good supply of clean, fresh diesel or high-quality, commercially-produced biodiesel (or a mix of the two). I would run it out of a clean fuel jug under the hood to eliminate an issue in the rest of the fuel system. Install a new fuel filter that is high quality (Mahle, Bosch etc). Fill the filter with clean fuel first. One important thing -- when you remove the old filter, make sure the center rubber O-ring that fits over the threaded part of the filter head that the filter spins onto comes off with the filter! Look up inside the filter head with the filter off -- there should be no old rubber washers stuck up there. Many times the washer gets forgotten in there, or doesn't get put on at all, and that can cause air and fuel leaks or bypassing of the filter media and destruction of the injection pump and injectors.

I suspect your fuel supply is blocked somewhere -- maybe in the tank at the pickup if you have been running cruddy fuel -- or you have an issue with the injection pump or an injector, which might also be caused by WVO. Start by eliminating possible fuel supply issues by isolating the injection system (that is what the external fuel source is about). If it runs great that way, then you need to take apart the fuel system and find where it got plugged. If it still has the problem running off a clean external fuel source, then you need to start troubleshooting the pump and injectors. Is the rear timing belt too tight? If it is, it will wear out the pump shaft bushing, take out the seal, then the pump will suck air when it's running. When it runs, does it run kind of rough? A few months ago I had an injector stick open, which meant it pissed some fuel but mostly let air get forced in through the tip, and then that filled up the whole system with air and it would quit running. You may be looking at something like that too.

Just start eliminating variables and you'll find the issue.

Enjoy the cape! I used to live in Boston. Have fond memories.

[Eli]

Thanks so much for your help George. I did get it running and made it home. Not exactly when planned, but I did get back.

I recognize that I did start running WVO in a very nonchalant way. I really should have known better for all the reading I've done about it. I just got a filtration set-up from a local guy and he said he'd been running it blended with 15% gasoline for 5+ years and I got excited to try it. For the record all the WVO was filtered to 5 microns, and when it was running it didn't really run any differently. I will be installing a proper two tank system here shortly. Anyway, on to how it eventually got fixed.

I started with opening the tank to see if there was a blockage or if anything odd was going on with the in-tank pump. Nothing blocked, pickup screen seemed fine. So I thought I would backflush the in-tank pump just to be sure. Pumping it forward it seemed weak, and when I reversed the polarity I couldn't get it to pump backwards at all, even with fuel in it. It seemed as though I found the problem, so I reversed the lines going to the tank. Now the pickup was the return and the return was the pickup. I also disconnected the fuel pump, both the fuel line in the tank (so fuel could return without needing to push through the pump) and the power to it.

I then changed the fuel filter and topped off with good ol' diesel #2. Then I had to purge the fuel feed line. I'm sure there are all sorts of tricks, but with my limited amount of tools and supplies I oped for this method: Open your fuel line in the front, and attach a funnel to the fuel line in the back. Fill the funnel with fuel and raise it as high was you can. Fuel runs though the line, then you can attach both ends again. Alright everything is closed up and should be ready to go.

I knew the battery can't be doing the greatest because of stopping and starting every fine minutes last time the car was driven, and I knew it would take some cranking to purge the last bit of air out of the system. I had no idea how dead the battery actually was. I had even hooked up my friends car with jumper leads to get it started initially, but it had nothing. Alright battery needs charged. Evidently that's a 'no can do' on the Cape at 6pm on a Friday. We checked everywhere and asked everyone. All the shops were closed already and no one seemed to know anyone with a charger. Too many tourists (such as myself), and not enough locals. We asked all sorts of people, even went down to the docks in search of some rough necks who know how to get stuff done. We couldn't even buy a battery charger.

The next day we had to drive my friend into the Providence train station because he had to be home that night(I was suppose to be his ride). We picked up a battery charger there, got back, put the battery on the charger and spend the next day and a half realizing the battery was finished. We even got the car running and drove it around in that time. The battery just wouldn't hold a charge after starting the car. We sourced a new battery on the way home, barely got the car started for the last time. Swapped the battery on the way back, drove through torrential rain in CT, and made it back to PA at 4am. Once you got the car running it did great.

Once I found out how dead by original battery actually was, I suspected I may have misdiagnosed the in-tank fuel pump. That it just may not have had enough power. But now I am thinking that that was the problem. Maybe killed by WVO? I haven't tested anything since I got back, hopefully further diagnostics will tell.

Man, this was a long story.

Thank again for your support and input George!

I did have a great time up there.

-Eli

[hvguy]

you may have a french fry stuck in the feed-line lol




im sorry, im no help =)