GreaseCar WVO System - Solenoid Amperage Problem? - PeachParts Mercedes-Benz Forum

Blevinsax · #1 10-08-2006, 10:30 PM

I've had a GreaseCar WVO system installed on my 1991 350SD and although it runs extremely well, I have one final glitch to correct. Here's what happens:

I start the car and let it run until it is warm.
I change from Diesel (B20) over to WVO.
The car runs for a few seconds and shuts off. If I hit the accellerator up to about 3500 rpm's, it will just hickup and keep running, but if I simply let it idle, it will shut off. Then I can restart the car and after a very brief priming the car runs great on grease.

I have installed GreaseCar's auxiliary pump, it seems that I have good power to the system, and everything appears to be installed properly. It seems like the solenoid does not get enough power to open at regular engine operation - only at ignition does it get enough power to open fully.

................ finished this post entry a little later ..............

Okay, after some discussion (with my dad) I have perhaps determined that the power to my solenoids is at fault. At ignition startup, there is enough amperage to cause the solenoid to open, but during regular driving there is not enough amperage to open the solenoid. This seems to be why I cannot switch fuels while driving - the motor will shut down if I do. As it is now, I must find a place where I can stop to switch fuels. The motor will stop, then I can restart on WVO and everything runs beautifully. Also - when I shut down on WVO and leave the car for a little while, it will shut down again when I initially restart it. Again, I have to restart the car and then it will continue to run fine.

So the question is - where should the GreaseCar system solenoids be getting power? Right now I *think* my system is wired into the starter, but I could be wrong - I'll need to confirm it with my mechanic this week, but I heard him mention it when I spoke with him last week. If so, that could explain why it does not have enough amperage - the starter circuit does not get full power when then engine is operating - it only needs full power to start the car when cranking. Am I on the right track here?

Any recommendations?
Thanks!
P.S. I have posted this over at the GreaseCar forum, too, but nobody has responded - you guys here are a lot more helpful!

biopete · #2 10-08-2006, 10:58 PM

I like to run my solenoid valves through a relay. I use the radio fuse circuit for the switch so if my radio goes out, i know my valve is not going to function and can do something about it. Your mechanic will know how to do this but basically :

A wire from the battery to relay
A wire from radio circuit to switch and from switch to relay
A ground on relay
A wire from valve to relay

The idea is when you hit the switch, it allows the full power of battery to go to the valve while at teh same time using hardly any juice from the radio circuit and you dont worry about overloading the radio fuse.

I had a grease car valve i thought was working intermittently. Still not sure. it seems to work in testing. Id be interested to know if it is a faulty valve or just wiring.

TchTchr · #3 10-08-2006, 10:59 PM

I had a problem with switching when I first tried running my greasecar system. The cheap snap together wire splicer they supplied wasn't making a connection. I soldered the joints, and now all is fine. The power is suppied by the lead the cigarette lighter which is no longer used other than for radar detector and xm radio - solenoids work fine. Have you posted on greasecars forum? Grease posts usually have better responses there. This place is great for all the other mechanics. Without this place (as well as local Mercedes owners) instead of doing the work myself, my auto would have gone to the shop many times over.

P.E.Haiges · #4 10-08-2006, 11:11 PM

Blivin,

Current (what U call amperage) in a DC system is dependent on voltage and resistance.

Check the voltage at the solonoid to see if it is 12 volts. If the voltage is less than 12 volts, trace back thru the circuit to see where the voltage drop is.

I can't figure what your mechanic is talking about. When the engine is running, the starter doesn't get any voltage (or current or power).

The best place to wire in the veggie system would be the terminal block that is connected to the wire from the starter solonoid terminal that is connected to the + terminal of tha battery. The veggie system would always be "hot" even if the key switch is turned off.

P E H

Matt L · #5 10-09-2006, 12:33 AM

Quote:

Originally Posted by P.E.Haiges

Current (what U call amperage) in a DC system is dependent on voltage and resistance.

I think you mean dependent on potential and resistance.

Blevinsax · #6 10-09-2006, 01:36 AM

Quote:

Originally Posted by biopete

I had a grease car valve i thought was working intermittently. Still not sure. it seems to work in testing. Id be interested to know if it is a faulty valve or just wiring.

We initially thought it was a defective valve, too, but I called GreaseCar and they sent me a new valve - free of charge. I had it installed and the problem persists, so I don't believe I would have TWO identically defective valves. I'll check out the radio relay idea - that sounds like a good plan to me!

Quote:

Originally Posted by P.E.Haiges

Check the voltage at the solonoid to see if it is 12 volts. If the voltage is less than 12 volts, trace back thru the circuit to see where the voltage drop is.

I can't figure what your mechanic is talking about. When the engine is running, the starter doesn't get any voltage (or current or power).

The best place to wire in the veggie system would be the terminal block that is connected to the wire from the starter solonoid terminal that is connected to the + terminal of tha battery. The veggie system would always be "hot" even if the key switch is turned off.

I do have 12 volts at the solenoid - I just don't have the amperage there when the engine is running.

That is true - the starter gets no any power when the engine is running. That's probably why my solenoid does not open.

Initially, we had the system wired "hot" even when the key switch was off, but because I have the aux pump on the same line, I could never leave the switch on WVO when I leave the car because the pump would sit there running. That's why I need to find a circuit that is OFF when the engine is not running, yet still gets full power when the engine IS running.

WD8CDH · #7 10-09-2006, 08:35 AM

If you have 12Volts at the solenoid then you need to check the ground on the other solenoid wire. If you have 12 volts ACROSS the solenoid and it doesn't work, then either it is broken or stuck up with crud rather than an amperage problem. If you had an amperage problem, then you would not be able to get 12 volts ACROSS the solenoid.

Jmana · #8 10-09-2006, 08:54 AM

This sounds identical to what I have been dealing with, with my Greasecar solenoids, but my problem isn't electrical, it's that the internal seals don't seem to be able to hold much suction, and when I get above a certain RPM, the solenoid lets large amounts of air into the fuel lines. If you'd look at how small the orifices are inside that valve, you'd realize that that is a LOT of suction being put on the fuel to get it to go through the small openings. At idle, it's fine, but you get above 3K rpm and within seconds I can feel the air getting into the IP. I've tested this while at idle by restricting the flow of WVO into the solenoid, and as soon as I do there is a big whoosh of air bubbles that comes out the outlet. Don't know if this is your problem also, but it sure does sound like it. And I tested both my solenoids, and both were the same, so I think they have a serious defect that needs to be addressed.

cavaliers16 · #9 10-09-2006, 08:56 AM

Do this with a friend- have him/her sit in the car and flip the Greasecar switch. You, standing over the engine, should hear the valves making audible clicking noises as they change from diesel to vegetable and back. Then try it with the car on. You should still be able to hear it. If they aren't making any noise you've got bad wiring. Here's how I wired mine:

Wire your solenoids directly into the fusebox. Mine (300D) has those round ceramic fuses that clip in to metal "arms." If you take one of those round connector ends that comes with the kit (or get a box at the store) and put the pointy end of the fuse through the hole and clip the fuse in your valves should get power. Just put the connector on a fuse that has power when the key is in.

Diesel Dan · #10 10-09-2006, 11:33 AM

I wired my solenoids into the wire for the cigarette lighter, and everything works fine. I agree with others that the quality of the Greasecar solenoids is suspect. I think I have some bleed-over between veggie and diesel, as the seals in the solenoid are not able to handle the suction. I've not had any performance issues on WVO though, but I wouldn't be surprised if I am getting some air in my system. I do have a big air bubble in my diesel prefilter most of the time. My switchovers from diesel to WVO are smooth however.

Jmana · #11 10-09-2006, 01:37 PM

Dan,
Do me a favor. If you have clear lines, get the car running on veggie, and take a pair of needlenose pliers and compress the veg line going into the solenoid, and see if you get a bunch of air coming out the outlet. I think you'll find this to be your problem, especially if you have a looped return. I'd like to know what you find, because if enough people realize there's a problem with the solenoids, perhaps we can get Greasecar to replace them with a better made product. I have a feeling the orifices are too small for running something as thick as WVO. I've seen pics of the orifice, and it's only about as big around as a pencil point. Now think about how much fuel an MB fuel pump puts out, and the viscosity of veg oil. This must create a lot of stress on the seals, especially at high RPMs when the pump is running at full speed.

WD8CDH · #12 10-09-2006, 04:48 PM

Usually air gets into the system thru a bad fitting or connection to a fitting rather than the valves (assuming the head is properly tightened to the body).

I have found that fuel injection type hose clamps are far superior to worm gear style clamps for preventing air leaks.

Also using an auxillary lift pump for veggie and the stock lift pump for diesel helps prevent air problems and allows faster switch over and purging too.

Jmana · #13 10-09-2006, 05:37 PM

The air is not getting into my system through a bad fitting or loose hose clamp. I can see exactly where the air is coming from, it comes directly out of the solenoid. If it was coming from a fitting, there would be air visible at idle. But this air is getting dumped in all at once, once the rpms hit a certain point, that's what made me suspect the solenoid. Then when I restricted the flow going into the solenoid at idle, I could see that's exactly where it was coming from.

Blevinsax · #14 10-14-2006, 02:12 AM

Okay - I left the 350SD with my mechanic for two days and he checked, checked, and rechecked everything in the GreaseCar system. Everything checks out - no amperage problems, power is good, solenoids are working, but I still have these same two problems:

1. the car stalls after switching to grease from diesel, then restarts fine with a brief priming.

AND

2. after shutting down and leaving the car on grease with the motor off for at least 15 minutes, the car stalls shortly after restarting, then restarts fine with a brief priming.

This tells me that when the grease line is not flowing, it is running back down the line and air is getting into the line. It seems to be up front in the system because it takes longer to reprime the motor if it has been off for a longer period of time, but it reprimes much quicker if it was running very recently. So where is air getting into the line???

Quote:

Originally Posted by WD8CDH

Also using an auxillary lift pump for veggie and the stock lift pump for diesel helps prevent air problems and allows faster switch over and purging too.

I should also mention that I already have the auxiliary pump from GreaseCar - Initially we thought the stock lift pump was not strong enough to pull grease from the trunk, so that was the first thing I did when this problem surfaced, but it did not remedy the problem. It is now one of the primary suspects for the air leak, too.

This system is so close to perfect, but this last little hitch is really annoying. The car runs so great on grease, but I cannot switch on the fly or the motor will die. Ultimately that causes me to run a lot more on diesel than I would like because I have to find a place where I can safely stop so I can restart the motor after it shuts off when I switch to grease. I've already burned through a half tank of diesel in a week - I was hoping a full tank of diesel would last 6-8 weeks like it does on our VW. I know the VW motor is smaller, but so is the VW diesel tank at just 14 gallons compared with the 22 gallon tank on the Benz. A tankful certainly won't last that long at this rate - and that stinks because I have an endless supply of WVO I could be burning if I could get it working properly.

The one thing my mechanic discovered is this:
While driving - when switching from diesel to grease, he let it go just until the motor started to die, then he flipped the grease/diesel switch back and forth several times. When he did this, the car picked up and kept running. Naturally, I'd rather not have to do that every time I change fuels - I'd like to get to the bottom of the problem. After all, this IS a Mercedes!! It's the nicest car I've ever owned!! I shouldn't have to be driving it like some half-ass redneck pick-up truck that only works if you 'whack it' or 'thump it' or otherwise 'jimmy-rig' it! As it is right now, I have to 'whack it' under the passenger dash to make the A/C blower work , but never fear - I've already ordered a new fan blower motor, so I wil have that repaired sometime soon!

Okay - Anyone have any suggestions that might help me figure this one out?

P.S. I posted this same thread over on the GreaseCar forum and got NOT ONE response!!!

Blevinsax · #15 10-14-2006, 05:15 PM

Has anyone had luck swapping Frybrid solenoids for the ones supplied with the GreaseCar kit? Wouldn't be too complicated, would it?

I'm pretty convinced that the solenoid design is the root of the air-in-fuel problem I'm experiencing. I contacted GreaseCar and they sent me a new solenoid, but the problem persists. Everything is operating as it should, but air is still leaking into my grease fuel line - I cannot find any problems with the installation, nor can my mechanic - and he has plenty of experience with these systems. He also mentioned that GreaseCar has changed the solenoid design - could the 'new' design be the problem? The older GreaseCar system on our VW has no such solenoid problem - in fact, it works perfectly. That's why this problem is so frustrating.

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