Solve this cranking no start, will pull start condition!

[prazepam]

Hi! Thanks for the add. I have lurked for a a while but am registering today to ask for help in diagnosing my car! I'm stumped.

About the car: '82 240 with a '79 300D (NA) engine with a custom two-tank wvo kit with separate filters and a delayed purge to prevent diesel contamination. Last I checked compression was around 260-280 psi in all cylinders (it's an old engine).

I have rewired the glow plugs to run off a ford ignition solenoid and a push button. I have confirmed glow plugs are heating by removing them and shorting them to 12V. they also are all reading 12v when the button is pushed. Alternator is from a saab 900 rebuilt, rated to 120a, also wired with heavy gauge and I have not been experience charging issues.

The problem is the car tends to want to stall on idle and I have to pull the idle adjust to keep it running when coming to a stoplight or off the freeway. It can also smoke a lot at idle. Then a few days ago it died at a stop sign and I was unable to start it with the starter. cranking for 20 second intervals until the battery needed charging. I had been having intermittent starting issues for a while previously (hence the glow plug rewire), but this time I couldn't get it started at all. I was able to get it towed to my friends house.

I fully charged the battery (low from cranking when it stalled in the street). I installed a WOSPerformance gear reduction starter and rewired the starter to battery. I changed the fuel filter (my suspect for the dying on idle) and the air filter while I was at it. Still cranking no start. I cracked the injector lines and purged air until I saw fuel, closed them and still cranking no start. Took the battery to autozone and they confirmed it was good and fully charged.

I had a friend pull start with a tow strap and it started instantly in 2nd gear. I was able to drive it in stop and go utilizing the idle adjust to keep it from dying on idle. I drove 8 miles towards home and at high rpms it drives fine. Then it died in an intersection and I was unable to start it with the starter, just more cranking. My friend pull started it again and we towed it home. I fully charged the battery and still it cranks but no starting.

What are the potential causes for this strange condition? I suspect its wholly unrelated to the veggie oil setup, and am suspecting the fuel injection pump. I would appreciate any guidance. Thank you in advance!

[Diseasel300]

If you had air in the injector lines you need to find out why. There should NEVER be air in the fuel system.

260-280PSI for compression is getting pretty poor. If it's been a while since you've checked, it would be worth checking again, you may not like the numbers. When you tow-start the car, the RPM of the engine is likely higher than it is when cranking with the starter. If low compression is your culprit, the higher RPM is necessary to overcome the lack of compression. When's the last time you adjusted your valves?

If you're running WVO, it's not unheard of for residues in the oil to gunk up the injection pump or score the injector nozzles.

[tomnik]

Hi,

Where is your timing?
Hot and cold the same starting issues?

Tom

[prazepam]

I last adjusted my valves maybe 5 thousand miles ago.

I use wvo settled then filtered to 5 microns, and in the car from the tank I have a prefilter, a vormax/racor heated filter, then another prefilter before it hits the injection pump, and I check the prefilters regularly. I also purge with petrodiesel always and so the only times wvo is in the pump is while the car is running. Could this still create residues? I have found no evidence of polymerization in my crankcase oil btw.

Hot and cold same cranking no starting.

I rotated my engine to OT and I saw both of the cams were pointed up for the first cylinder, but I haven't checked anything farther.

[Father Of Giants]

Unfortunately it sounds like the motor is in it's death throes...

[tomnik]

Check your IP timing. I bet you're out.

[rocky raccoon]

Once started and running well, try running on Diesel fuel. You would be amazed at how much better our DIESEL engines run on DIESEL fuel.

[97 SL320]

Are all of the glow plugs operational? Even once running, a glow plug is still a hot spot making for smoother operation. Given your compression is low, glowing a warm engine is probably needed.

I'd dump the veg system and concentrate on regular fuel only.

So you are the guy at 2:40 + ( the good part starts at 4:17 7:40 , more fun stuff from 830 - 8:40 ) https://www.youtube.com/watch?v=FXEFY48IDkE


See more cars in , https://www.youtube.com/watch?v=MpyQwy6uuK4

[prazepam]

Well, the 8 mile drive I described was on petrodiesel. When it died at the stoplight I was running on petrodiesel. All of these issues occur regardless veg/diesel. I have separate fuel filters, three solenoid valves, and a check valve after the diesel filter so I am sure I am not getting cross contamination with my fuels. I understand veg oil is controversial, but the symptoms I'm describing don't deal with the veg oil components, as I don't start on veg oil.

I thought minimum compression on this engine was 200psi? Does anyone have functional engines with compression like mine?

All glow plugs are confirmed operational. I usually run the plugs for 25-30 seconds before cranking. Are you suggestion an afterglow relay to run the plugs when the engine is already warmed up? My issue is with starting, so that seems like a fix for a different problem.

Trying to figure out how the video is relevant- are you suggestion I startup with ether or wd40? I've understood those to damage an engine...

As for the pump timing, does anyone have a good tutorial on checking that?

[barry12345]

The unburnt residue from wvo can coke up the rings. Or if the car is not used daily turn to a very strong gum type adhesive in the ring lands. Injectors can get in pretty bad shape from it as well.

I am not a fan wvo myself. It takes some effort for example to even dewater it. I suspect that is what killed so many injection pumps using it in the day. Processing a water component through injection pump elements. Is abrasive in nature.

Anyways I would do a new compression check. If lower than the last time. Do a cylinder soak for about a week. Then recheck compression. Starting with a pull and not with the higher speed starter you have. Is not a good thing.

Of course make certain the glow plugs are really working. The interior light should dim when you apply the glow plugs.

[prazepam]

Originally Posted by barry12345

The unburnt residue from wvo can coke up the rings. Or if the car is not used daily turn to a very strong gum type adhesive in the ring lands. Injectors can get in pretty bad shape from it as well.

Interesting. So this could be from partially burning wvo, maybe at idle? Wouldn't this be expelled in the exhaust stroke, or burned off when purging with petrodiesel? I never park the car for more than 15-30 minutes on wvo. If it's any more time than that I will purge to petrodiesel.

I definitely don't drive daily. Sometimes it's parked for a week. I'm gonna borrow the compression tester from a friend and I will let you all know what's up.

Just to check, to re-time do I line up the OT mark on the crank with the camshaft, then unbolt the IP, line it up and rebolt it carefully after rotating to 25-26 degrees?

Thanks everyone for their help! I figured wvo was safe as long as I had processed quality settled oil, only burned it when it was in a hot engine and heated to 80+ degrees C, and if I always purged to petrodiesel afterwards...

[97 SL320]

Originally Posted by prazepam

Trying to figure out how the video is relevant- are you suggestion I startup with ether or wd40? I've understood those to damage an engine...

I was referring to the multiple laps at 4:17 to 7:40 being towed behind a station wagon.

Ether for a diesel will cause damage however, it compression drops to the range of a gasoline engine, ether is the only way it will start.

Veg oil / old motor oil in a diesel is a disaster. Sure, it will work for a while but it gums up pumps, injectors , piston rings. Given you have low compression and likely poor injectors, unburned fuel is still in the combustion chamber and will get to the piston rings.

Any damage caused by the veg system has already been done, simply switching to regular diesel won't fix the issue. Fix the engine and run on diesel until things are stable then decide of going back to veg is worth the risk.

A few possibilities on the will start on a tow but not with the starter.:

The battery has a shorted cell ( An actual shorted cell not the generic " It is shorted " some use for any electrical problem. ) A shorted cell is like installing a 10 volt battery, it will provide electrical power for as long as a 12 v battery but cranking speed will be low.

The starter is worn out. Starter have 4 field coils and 4 brushes. If you lose a brush, starter power will drop by half as will cranking speed.

If the starter drive is slipping, the starter will spin but not turn the engine. While cranking, look to see if the fan is spinning.

Some sort of issue allowing the engine shut down system to remain engaged while cranking. I can't offer any details as to how this would occur )

[rocky raccoon]

I strongly suggest you do not mess with the pump timing unless it has been removed in the past. I feel certain that your problems stem from the use of wvo for fuel regardless of how it is stored/treated. Hopefully your pump and injectors have not been compromised beyond restoration.

[mbolton1990]

Do a diesel purge.
After change your filters,also check your in tank filter if you haven't in a long time.. thats where I'd start but if you have bad air intrusion that's sinking the ship..

[GregMN]

You have 2 places in your diesel motor that require high compression for your motor to run. The cylinders in the engine and the cylinders in the injection pump.
The cylinders in the engine can loose compression around the piston ( worn rings and/or cylinder walls ) and by the valves not seating anymore.
The injection pump will not make enough compression to fire the injectors properly when it gets worn out.

Burning WVO can stick the rings in their grooves in the piston. This usually is from burning WVO that is too cold to be sprayed in a good pattern out of the injector, so it dribbles out and the unburnt WVO ends up on the cylinder walls and is scraped up by the pistons and bakes in the grooves. This can be from the WVO system not heating enough or usually from the operator switching too soon.

Water in the fuel system can damage an IP. WVO, as fuel, is home made to no standards from unknown source stock. Removing water is so important. Micro droplets of water is found in the cleanest WVO. These micro droplets of water, when put under the pressure that is present in the cylinder of an IP, will explode with enough force to pit the metal on the walls of the cylinder. Over time the IP will not be able to create the pressure needed to fire the injectors.

At the beginning of either of these conditions, the engine will become hard to start at the speeds the starter motor can turn it. Once started with a tow, as you have done, it will be turning enough rpms to continue to run.

Don't go chasing IP timing, or throwing any money at it. At the compression when you last checked, the motor is tired. Go ahead and adjust your valves, run it up to temp., let it cool, and then check the valves again.

Save your money for your next car. That's just my opinion....