I have a 1980 300CD/WVO car that I got last week. Its my first diesel and has been running fine on a dual tank WVO setup. Well this morning she didnt want to start. It seemed like a weak battery that progressively got weaker. I did purge back to diesel in the lines before shutting it off last. Jump starting also didnt help at all, still seems somewhat weak but sounds like it should fire. Where can I check? Glow plugs seem fine... Is there anyway to make sure there is no congealed WVO in any lines or injectors? Im mechanical but this is my first diesel!

Thanks,
Zack

If the battery seems weak remember that you must be cranking at least 100 rpm to start. Take the battery out and have it checked.

__________________
1977 300D Lost coolant while someone else was driving
1983 300D Can't run without oil
1985 300SD (gone but not forgotten)
1990 300TE 4matic Sold
1991 Yamaha Venture
1975 Kawsaki 250 triple
1974 Honda 200CL
1951 8N Ford
2008 Wildfire 650C

Zack,

How did you determine that the GP "seem fine"?

P E H

Well I also tried another battey that should be good and I had the same issue. In regards to the glow plugs, I tried checking the resistance on the pins at the junction block on the right(per Haynes manual, I believe I tested the right ones). None of them should infinity but they did range from 0.5ohm-1.5ish... I tried hand priming as well but is there anyway to make sure there isnt congealed wvo anywhereand that diesel is making it through the injectors? Any troublesooting ideas?

Thanks,
Zack

Zack,

You might take out the GP with higher resistance and connect them directly to the battery. Use a Vise Grip wrench to hold the GP. The tip will glow bright orange if the GP is OK.

To see if fuel is being pumped to the injectors, loosen the nuts on the injector pipes and see if fuel leaks out when the engine is cranked. Its unlikely that the injectors are plugged because of the high injection pressure.

P E H

I checked the GPs again with the voltometer... It seems all 5 are around .6 ohm. The plug has 7 wires total and 2 read differently but they are a different gauge and marking style so I assume they are for something else.

Where is the GP relay fuse? In searching I keep hearing to check it, I dont suppose its the metal strip in the same box if so that looks fine. The light functions as normal (10-15sec) but there is no click or noise when the light shuts off... Anyone else have ideas before I pull the GP's? I hate having to pay for gas to commute in my other car

Zack,

I hope you used an ohmeter to check the resistance of the GP LOL. But 0.6 ohms sounds like all the GP are ok.

Did you do the cabin light GP test? Use search to find it.

Yes the GP fuse is the metal strip inside the GP relay box.

The GP relay won't click off for about 45 seconds regardless when the dash GP indicator turns off. You should hear the GP relay click on when the key is turned to the run position and click off after about 45 seconds if you don't turn the key to the start position.

The GP relay turns off the GP when the key is turned to the start position regardless of how long you wait as long as its less than 45 seconds.

P E H

P.E.
First I appriciate all your help, I did try the cabin light test, and It did dim when the ign. was switched on. I am thinking more and more it may be fuel related. The handpump will push fuel and I can see it going through the clear filter, but as I pump some fuel will overflow from the handpump making me think there may be some blockage somewhere. It could be possible I have some congealed Veggie oil in an injector? Should I try pulling an injector to see or try something else?

Zack

The hand pump on my 300cd leaks as well. I had a similar starting issue over the winter. New glow plugs did the trick. The old ones had some build-up. Once replaced there was a big improvement in start-up.

They are cheap and easy to switch out. A leaking priming pump can let air into the fuel system.

You may also want to consider cleaning the contacts on the wires between the battery and the starter.

__________________
1985 300SD, 203,000 miles, dark blue

Lil Sarah says: "Poor old Grandma Blue Car...She's sad."

A couple of years ago I had my car die at a red light and could not get it restarted. Ended up having it towed to the shop. It turned out to be a crack in the plastic priming pump body that was letting air in. It's worth upgrading to the new type of pump just to get rid of the leak, anyway.

Zack,

I was going to suggest replacing the primer pump but I see others have beat me to it. If the pump leaks fuel, it can leak air into the fuel system. A new primer pump is about $15.

There should be resistance when pumping the primer pump. You have to overide the pressure relief valve in the IP once the air is purged from the fuel system.

I don't think congealed WVO would block an injector. The pressure (~1500 PSI) is too high. Also if one injector was blocked, the engine would run on the other cylinders. You could take the injectors out of the head and reconnect them to the IP and observe how they spray fuel.

Did you crack the fuel line nuts on the injectors to see if fuel leaks out when you crank the engine?


P E H

I run 80% WVO and 20% diesel, kero, or sometimes (rarely) gas.

I start the car in the morning every morning, even when the temps drop into the 60's

I routinely must depress the accelerator pedal at start. Crank, mash the pedal, starts.

Have you noticed decreased performance??? That would indicate a clogged fuel filter. I will soon be adding pictures of a fuel filter that, quite simply, had enough french fries and fried chicken - to my website.

Glow plugs are essential, as is a good glow plug relay. Measure the voltage coming out of the GP relay (located on the left fender well) you can do this on the GP's or on the relay. I guarantee that if you don't have glow plugs, the car won't start for a long long time cranking, at which point I would suggest buying a back up starter.

Also a clean air filter might help. you can add some propane to the air filter to help start the car, propane works on diesels like ether does on gas engines.

And finally congratulations on burning WVO. My 300SD passed the emissions tests here in Ohio, blowing a total of 0.0% particulates out of a max of 20.0% (or whatever ppm)

www.benzbonz.biz

Marty

Well I ordered a new primer pump and 5 new glow plugs just in case tonight. The fuel filter in the car has been reloacted to the trunk due to the WVO setup. Is the nut to loosen on the top of the housing? Also there are 2 a larger center one and a smaller nut which is loosened for priming? Hopefully next week when everything gets here she'll be purring again:-)

Thanks,
Zack

Zak,
Here is a starting hint for diesels which don't like srtarting in the cold.
Remove the aircleaner cover.
While cranking, have someone spray WD40 or similar light oil into the inlet manifold. If engine fires, have them continue spraying until the engine revs up under control of the pedal.

ANother one I use is a teaspoon of RUG into the inlet manifold. Often the Gasoline will allow the engine to fire, then the additional heat will allow it to continue running.

__________________
Tony from West Oz.
Fatmobile 3 84 300D 295kkm Silver grey/Blue int. 2 tank WVO - Recipient of TurboDesel engine.
Josephine '82 300D 390kkm White/Palamino int.
Elizabeth '81 280E, sporting a '79 300D engine.
Lucille '87 W124 300D non-turbo 6 cylinder OM603, Pearl Grey with light grey interior


Various parts cars including 280E, 230C & 300D in various states of disassembly.