I'm hoping to get a little advice on my 82 VW truck, running Biodiesel (B100) for about 5000 miles (since a new 1.9L engine was put into it).
It started running rough this week, like it was starved for fuel, and I noticed air bubbles in the line before the injector pump. I checked all fuel line fittings, and replaced a couple that were clips with the stainless threaded ones. I let some fuel drain from the tank to make sure there were no blockages. I changed the fuel filter and refilled the new one with ATF before installing it (I read somewhere that ATF is good for cleaning the injectors). I removed the metal fuel lines that go from the injector pumps to the injectors to make sure they weren't blocked, then removed the injectors. When I did that, I noticed that one of my return line hoses on the injectors was frayed, so I replaced all the return hoses, put in new heat shields, replaces the injectors, put the fuel lines back on.
That is about the extent of my diagnostic ability. I can't find a physical leak where air could be getting in. When the engine lurches to a stop, I can see air bubbles (lots of them, big ones) travelling back up the hose from the injector pump to the fuel filter. I can even hear air coming in somewhere, this faint sucking sound, but it really sounds like it is somewhere in the injector pump, and I can't see it at all.
Is my injector pump bad? Is there another test I can do? Also, is it bad for the engine if I nurse it to the mechanic in this shape--I can get there, but it is a bumpy ride--should I tow it instead? Any help or advice would be very much appreciated.
thanks!
have you tried running it out of a can to bypass all the lines and filter? mine the check valve was faulty.
I haven't; I have always been too worried about non-filtered fuel to just throw the line into a bucket.
i had this it was a bad seal on the return lines into the fuel filter, it seems that unless you use a orig filter the little rubber `o` ring dont fit(fram worst) you could see if you can get a bigger `o` ring or use a sealant carefully,hope this helps
Ray
I'm using Bosch fuel filters, and have never had a problem with the filter sealing with these.
Someone else suggested maybe a bad injector pump. I opted to try running it out of a can, and put the fuel-in line directly into a new bottle of ATF. Once primed, it ran fine, like nothing had happened. I think that tells me that the injector pump is good, and that there is a blockage. the question is, where?
I need to remove the tank to fix my fuel sender, so I'm thinking that I might as well go for it all at once, and check out the in-tank screen while I'm at it.
Any tips on fuel tank removal methods?
The fuel sender is right behind the rear seats under a panel, as for your rabbit truck, it may be under the bed of your truck......
Air bubbles from the pump towards the filter? That's backwards. You're sure you have the send and return lines on the right way?
today I removed all of the fuel lines to check for blockages, and found none. I ran it directly out of a can of ATF again, and I noticed a fuel leak at the base of the injector pump; this would explain the air coming in on the pump side.