Lose power on WVO; HELP

[Richard]

Can someone please help me with this confusing WVO conversion problem? I would be very grateful.

I have a 1993 Mitsubishi Delica with a 4 Cyl. Turbo Diesel engine. I have converted it to WVO (Canola). My conversion generally consists of: WVO tank, filter with glow plug heaters, secondary glow plug heater with coolant heat exchanger, 3 way valves (fuel feed and return). My system is almost identical to my brother-in-law’s who has a 1992 Delica turbo Diesel and he has no problems.
I have a confusing problem. When I switch to WVO, the van runs great for about 1-2 minutes, after which the van runs great at low RPM’s but after half throttle, I lose most of my power. I have driven the van in this condition for an hour on flat terrain; however as soon as I hit a hill, it has trouble making it up. When I switch back to Diesel, the problem persists with identical symptoms.
The only way to correct the problem is to turn engine off and let it sit for a while. Then when I start it up on diesel, it runs perfectly fine. When I restart the engine on WVO, it again runs fine for the first 1-2 minutes, then the problem restarts.
I’ve been over the system several times looking for air leaks or other problems, even swapping each part of my WVO system with my brother-in-law’s system (his van runs great on WVO all the time). I don’t know what else to try. Can you please help?
I don’t think it is an air leak because the problem persists even when I switch back to diesel. Also, when the van sits for a while, the problem clears up (until I run WVO again).
I don’t think it is insufficient heat because when I restart the engine on WVO, after it’s been sitting, it runs fine for the first minute or two. Also, after a while of operation, my glow plug heaters kick off due to a little thermostat control switch on the side of the heater/heat exchanger.

Please help me. I have no idea what to try next; any suggestions? Thanks for your time.

[TardisDeli]

I'm no expert on this topic but i've help on a install on some else Deli and he had a similar problem to this.It involved the way we set up the return line for the wvo feul. So we need to know how you have it set up?

[after oil]

sometimes the WVO problem will persist after you switch to diesel for a few minutes because is flushing the wvo out still.

perhaps one of your wvo lines is collapsing under pressure.
did you look inside the wvo tank and check for air leaks there?
the diesel tank? check it if you modified it in any way.
is there sufficient venting of the WVO tank to allow for sucking air in when wvo goes out? or do you hear a "pfffft" when you open the wvo tank?

[BCDelica]

is there sufficient venting of the WVO tank to allow for sucking air in when wvo goes out? or do you hear a "pfffft" when you open the wvo tank?

My first thought too Ari, with the problem going away after sitting air could be making it's way back into the air space above the WVO.

Richard, do you have a looped return (WVO return from the IP is introduced back into the feed hose) or does the injection pump return go to a diesel/WVO tank?

[Adam]

I'm having a similar problem right now. I'm convinced it is because I've got a bad kink in my WVO fuel line, which I have yet to find time on a dry/snow free day to fix. Gotta do it this week though. My symptoms of power loss persist for a few seconds to minutes after I switch back to diesel from WVO because I've introduced air into the the system by sucking through the kinked hose. The recovery time depends on far I want to push to the power loss on WVO. When I was really pushing it I was having trouble starting and running the van in the mornings, even though I'd plugged it in, flushed it with diesel and it was running decent when I'd switch back to diesel before stopping. My theory was that air I'd introduced into the engine settled over night into a spot on the engine that made starting/running really difficult. An interesting side note is that if I parked the van in my driveway facing downhill it was much easier to start than when I parked it facing uphill. It seemed like the air collected in a different spot depending on the orientation of the van. Either way it pissed off my wife cause she had trouble running it first thing in the morning, so I gotta fix the kink this week.

[Richard]

Thanks for all your thoughts on this problem. I finally got to the bottom of it, with the help of Coombs Country Auto. Turns out it is my injector pump. It needs rebuilding. Although it is still a mystery why the problem persisted even when switiching back to Diesel; I guess some mechanical issues are mysterious and preplacing the part is just the way to go. Rebuilding the injector pump is approx. $1.200.00. Ouch.

[PlantDrive]

This does not sound like injection pump. It sounds like it is simply sucking air someplace on the WVO side.
Start by changing the WVO filter. See if that helps temporarily. Also test that crappy glow plug heater idea in your WVO filter and make sure the glow plug is working (great, just what the world needs, MORE glow plugs to fail! Yuck!). If the filter is cold and or dirty, the system vacuum will increase, and the system will then starve for fuel and/or suck air.

If changing the filter helps temporarily but then the problem comes back fairly soon, then you need to be checking all the clamps and fitting on the WVO side of the fuel system for air leaks. If the air leak is really bad, you might even have this problem with a clean, warm filter.

Clear line on the return line from pump back to return valve can be a great help in diagnosing air problems. I have some that works well, for diagnostic purposes, if you need a length of it, let me know. I would NOT rebuild the pump without checking this our thoroughly!

Also check that tank venting, look for kinked or cut hoses (an overtight clamp can cut into a hose and cause an air leak), etc.

[PlantDrive]

I'm having a similar problem right now. .....An interesting side note is that if I parked the van in my driveway facing downhill it was much easier to start than when I parked it facing uphill. It seemed like the air collected in a different spot depending on the orientation of the van. Either way it pissed off my wife cause she had trouble running it first thing in the morning, so I gotta fix the kink this week.

This also indicates an air leak in the system, in this case the diesel side or internally in a valve, or at the diesel filter, or at a seal in the injection pump. The fuel is draining back overnight because if you have an air leak, it becomes a vent, letting air in, when the engine is not running, allowing the fuel to drain back somewhat in the diesel line, so that you have an air gap in the line when you go to start the engine.

[loki]

If ccautos says it the pump it's the pump, if he says it's aliens living in the turbo, then it's aliens in the turbo, he will not steer you wrong.

[Richard]

The mysterious problem is becoming more mysterious. As suggested by Glen (at Coombs County Auto) I have had my my injector pump; first resealed (cost $450.00) and secound rebuilt (cost $1,200) and I have the indentical problem as before I spent the $1,650.00 on my pump.

(As a reminder, the problem is as follows: when I switch to WVO the engine loses significant power at higher RPM's (in fact won't rev over 3,000RPM). When I switch back to Diesel the problem persists indefinately (more than 1 hour during one test). The only way to correct the problem is to turn the engine off and wait at least 3 minutes (wait time increases the longer engine was run in problematic condition). After sufficient wait time and restarted on diesel, engine runs fine.)

What is interesting is that while Glen was rebuilding my injector pump, he installed an old pump from a 1992 Delica to keep me on the road. I ran that temporary pump for two weeks on WVO and it ran perfectly (this is one of the reasons Glen thought my pump needed to be rebuilt). This also verified that my WVO conversion system is not likely the problem. When Glen reinstalled my original, rebuilt, injector pump... the exact same, orginal problem returned. (causing me great frustration)

Looking into the problem, we discovered that the 1993 pump requires approximately 10% more fuel flow than the 1992 pump (new pump operates at higher flow rates with lower pressure). I installed a lift pump in my WVO system to see if that might help. It made no difference at all.

Any ideas? Anyone?

[EricN]

Change your filter and drain the bowl.

[Luna-Sea]

Hey,
I thought I read in one the post in the "WVO" section, some one had to put bigger lines on.

Would love to see the problem identified,there has been a few issues of this lately.
I wonder if there is a common root to the issue.

I definitely have beers or snacks for posters on the Wvo troubleshooting topic.
I am not yet on WVO just still filtering and learning about all this.
So If you are passing through Nanaimo PM me. (any greasers actually)

is there sufficient venting of the WVO tank to allow for sucking air in when wvo goes out? or do you hear a "pfffft" when you open the wvo tank?

I have seen this one a few times be the culprit on various boards. That would seem to make sense with it running well for a bit and then not as the vacuum builds up.
Could you not eliminate this variable by running it for awhile with no cap on the tank for awhile?(that would be easy,knock wood)

Very cool to have all the support of some very greasy fellows
Right on!
or will be at some point for you I hope!