300TD with Grease Car kit stalling on diesel - PeachParts Mercedes-Benz Forum

pat_cain · #1 07-31-2006, 11:22 AM

I have looked at all the treads and still have a problem...

1983 300TD running a dual tank Grease car system, when running on grease it runs fine, 2 weeks ago it started stalling on diesel, replaced all the filters, tank screen and tried adjusting the damper screw. I have ordered "diesel purge" but have not received yet. Help...any suggestions any suggestion on where to by diesel purge local Metro - west Boston area.

Thanks
Pat Cain
Princeton Ma

aklim · #2 07-31-2006, 01:12 PM

Have you checked the lines going from and to the tank? I thought DP was more for the injectors? Since the car is running on WVO, I would think that the tank filter is clogged or a kinky line is to blame.

Jmana · #3 07-31-2006, 01:26 PM

If your fuel lines are under vaccum, then there has to be air getting into the lines somewhere. The best thing to do is replace your lines with clear braided line, so you can see exactly where the air is originating. Since you say it only occurs while on diesel, then it's got to be originating somewhere between the diesel tank and the switchover valve. Most likely you have a hose clamp that needs tightened, or a leaky fuel filter.

pat_cain · #4 07-31-2006, 01:51 PM

Thanks, does not seem to be vacuum related. Lines are clear, I use a "boat" primer and I pull fine. I also have a clear pre filter no bubbles...I know it seems like a fuel line/filter issue, but if I disconnect and run from a bottle in place of the pre filter I have the same issue.

Any suggesting would be apprechiated
Pat

Jmana · #5 07-31-2006, 02:36 PM

I didn't mean vacuum as in the vacuum system. What I mean is if you rerouted the fuel lines so that the lift pump pulls fuel through the filter. Normally it pushes through, but most veggie filters are designed to have fuel pulled though it, therefore creating a vacuum on most of the lines, and therefore increasing the possibility of air leaking into the lines. You will not see an air leak by looking at the prefilter, the only way is to have clear lines. It doesn't matter how much you bleed the system either, if you have a leak it will cause intermittent stalling or near stalling of the motor. The first thing you need to do is clue us in on what modifications were made to your fuel system.

TchTchr · #6 07-31-2006, 06:14 PM

Have you checked the Grease Car forum? Those guys usually have an idea what's going on. I have a GC kit in my '81 TD and had troubles at first getting the car to start. I retightened all my connections and primed and primed and primed the system to no avail. Figured out I had a bad electrical connection for the switch. It was one of those lousey one wire to two wire crimp connectors. I soldered the joints and that fixed it.

Good luck

Jmana · #7 07-31-2006, 06:47 PM

I am not very pleased with Greasecar at the moment. I bought 2 of their switchover valves, and one was defective. Basically the flows were backwards on it, which sent half a tank of veggie and diesel into my trunk before I realized it. I'll never get the smell out.

pat_cain · #8 08-01-2006, 08:35 AM

Well, I does not seem to be a "grease" issue. It runs fine on grease. To troubleshoot I actual disconnected the hose an ran them as original, it did not fix the problem. Last night replaced all hoses hopeing that it was a vacuum issue. No good.

Symptoms... starts runs on grease. On diesel after mutiple cranks it will start, at idle it will stall. If I start on grease and switch over at idle it will stall in about 5-10 seconds. ( yes, if I pump the peddle I can keep it running , but will stall when placed in gear) If I switch while driving it will run with a noticable lack of power on the highway, when slowing down it will stall.

The Greasecar set up is about 1 1/2 years old 1- 3port 1-six port.
Grease side - tank- 6port valve-primer pump-6port valve- prefilter -filter -IP
-return - 3port valve - tank
Diesel side - tank- prefilter- 6port valve-primer pump-6port valve- filter -IP
-return - 3port valve - tank
Everything about it says fuel supply ( air or lack of diesel) but....
My only other thoughts were the difference in viscosity... could it have an effect the the spray pattern if anything is dirty.

Thanks
Pat

Jmana · #9 08-01-2006, 10:12 AM

Have you checked to see if the diesel tank vent is clogged? After it stalls out, get out and open the fuel cap and if you hear air then the vent is clogged. That's the only other thing I can think of that would cause this. It can't be a fuel issue, because if it runs on veggie, then it's got to run on diesel. You aren't running with the fuel lines under vacuum with your setup, so I doubt there is air getting into the lines. Although there is one other possibility, that the injector return lines are cracked and somehow allowing air into the system, but I am not sure how that would happen because it doesn't look like you have a looped return, but it wouldn't hurt to change out those lines if old.

aklim · #10 08-01-2006, 11:00 AM

Or can he run with the fuel cap for diesel off?

pat_cain · #11 08-01-2006, 11:50 AM

Tried the fuel cap off a few days ago, will try again tonight, now that I have replaced the hoses. But I have tried placing a jar of diesel at the primary filter and running hoses direct out of the jar it did not help....It has to be something simple I am just at a loss

Pat

aklim · #12 08-01-2006, 11:54 AM

Could it be the pump is weak and finds it easier to pull more viscous fluid thru as opposed to the thinner stuff that slips back? I know it sounds rediculous but just throwing out SWAGs.

jonschwenke · #13 08-01-2006, 12:54 PM

If you haven't, try switching the input lines to your valves... Basically swap veg and diesel routes. if the car still wont start and run ( after priming and purging of air of course) on the diesel, you can be relatively certain your issue is before the fuel selectors since you say the veg route has no issues. If it does run on the "new diesel" side.. you've determined the issue is somewhere from the selector valve on. I only suggest because if I understood correctly, you disconnected at the prefilter for Dsl which is before your selector valve.

Also.... not to be a wise a** but are you certain that you have good clean diesel? it's not possible it's gas, contamintated fuel, etc.?

Best of luck

Jmana · #14 08-01-2006, 01:10 PM

Even though you ran straight from the prefilter, you could still have an air leak at the 6-port valve. If it's an air issue, that's about the only place left where it could be getting in. Try tightening the hose clamps there, and check the fuel lines for cracks or holes. If that doesn't cure it, then I really have ran out of ideas.

pat_cain · #15 08-04-2006, 08:37 AM

Well, here is the latest, ran 2 can of diesel purge thru....now my glow light indicator does not light. ( No it would not idle on the DP direct from a bottle)
Actually seems a little worse, real low idle on grease now.

No glow light indicator - ?? 2 or more plugs bad or bad relay??

It look like I will try and get it into a shop..

Thanks
Pat