I went back and see you had already cleaned out the tank and tank strainer. Good going. That only leaves the fuel line, lift pump and injection pump to clean out.

It is only optional to pass all the cleaning up if you have tow truck coverage. Right of passage for some ex WVO burners.

The larger nasty blobs you saw in the secondary spin on filter might have been pumped out of the injection pump when you did the lubro molly thing. I suspect this stuff is in the lift pump as well perhaps.

A couple of weeks ago I was recirculating some diesel cleaner through the transfer pump and injectors. Had a pop bottle with two lines into it.

I got out a spurt or two every second at idle. When revved up it would send out a fairly small but continuous trickle. I was expecting more. I have new filters. The pump leaks quite a bit when the hand pump is engaged. I have not checked the fuel pressure.

Just looking for confirmation. Thanks.

__________________
85 Merc 300D - Unwinding 31 years of wear
86 VW TD
Mahindra Diesel
Iseki Diesel

In 2007 I didn't own a diesel.

Sorry to nitpick, but should you start a new thread so as to keep this one focused on Kevin's problem?

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

In response to barry12345, I will clean the IP, lift pump, and lines ASAP.

In response to Jooseppi Luna, I too wondered about the "easy" stuff. It could be. Do any more experienced people sbscribe to this school of thought?

Hopefully, this Benz' time to shine is soon.

Well it is at least a good thing that you pretty well have run it down. It is either a lift pump involvement or the lift pump if good is really struggling to get a reliable constant amount of fuel available for it's function..

When it was coming out your overflow relief valve it was totally functional. As that flow reduced to nothing the fuel supply was dropping off.

Why I suspect crud is a lift pump does not have Much ability to be intermittent in performance. Certainly it is possible but not that likely on these cars.

The makers of lubro molly whatever it's solvent is. Did not design it for instances where really heavy cleaning was required. It to me lacks the strength and perhaps has the wrong solvent to deal with animal and vegatable fats.

There is still a fair chance in my opinion that if you clean the system out well you may be fine. If it is not then troubleshooting a cleaned out system should be easy. Do check the small primary fuel filter very carefully in the clean up as it did a number on one of our senior members at one time. Gunk inside was shutting down the flow through it periodically.

You are right of course in that there is now no indication that the injection pump has an issue. In reality they get a lot of blame quite often and in the end where not really involved. The pretty obvious clue was when the relief valve was overflowing and then stopped producing anything. That is extremely abnormal. All indications so far is that the burning of wvo in the past has not hurt anything important. Your repairs of the current issue should be cheap but labour intensive.

I brought my issue up as I wonder if my lift pump is up to snuff. I thought it to be similar to Mcsedes' problem. Scanty or no output of the the aux. pump.

Do I (Does he) need to install a pressure gauge on the output of lift pump. Or can we measure the output of the cigar hose?

I have done some research and read that a 1.5l idi Citroen puts out about 17.5liters/hour out of the return line at idle. That is about 300 ml per minute. Certainly not a 3 liter mercedes but it is a data point.

__________________
85 Merc 300D - Unwinding 31 years of wear
86 VW TD
Mahindra Diesel
Iseki Diesel

In 2007 I didn't own a diesel.

Important: From some people's posts, it seems that some people do not understand the set up I am running. I am not saying this to be rude, I am saying it to try to eliminate unnecessary concern. Right now, the only components involved in my system are the a homemade diesel can, hoses, lift pump, the spin on filter, the IP, hard lines to the injectors, and the return lines. In other words, everything before the lift pump is being bypassed.

Update: Today again, the car would not start. I cracked the hard lines at the injectors, and NO fuel is getting to the injectors. Looking at the clear line I have going to the IP, it looks like fuel is getting to the IP, but at what pressure. Could NO fuel come out of the IP due to lack of pressure from the lift pump (some people who posted previously led me to believe this could be the case)? As suggested, I am trying to clean the lift pump. If what I am doing now doesn't work, I will try to take it out and clean it (if people think that would work) or get a new one if I have to. I tried to test the lift pump (alone) and it seems to only put out a very little bit when I crank. I'll see if the clean I did helps. I don't think taking it out is too hard. I also want to use acetone to clean the IP, but I frankly am a little worried about it. I will keep everyone updated, and appreciate the continued support. Unfortunately, I will be away Thursday through Sunday morning, so if I don't resolve this by tomorrow, it will have to wait a few more days. I'll try to see what I can get done tonight and tomorrow, but I would like more people to weight in on how/if it is safe to use acetone in my IP (some people have already commented-and I appreciate these thoughts) and if they think the lift pump alone is the culprit and how hard/easy it is to get out. I think I saw a thread on taking it out on one point that made it sound not too bad, anyone know?

Well your problem is easy. To eliminate any possibility of anything obstructing the fuel availability. . Just feed your lift pump with a hose in a container of fuel.

With the output line from the lift pump disconected. Lots of resultant output when cranking. It is not in general the lift pump.

If output from the lift pump remains very low buy the valve kit for ten dollars and recondition the lift pump. If currently you do not have enough fuel pressure and volume to open the relief valve on the injection pump. You will not measure any pressure after it..

There is no flow from your return line after the relief valve currantly I am assuming. To be deemed operating as designed there must be overflow from the relief valve. Bad filters ahead of the lift pump can kill this as well. That is why I suggest the disconnected outlet from the lift pump unless the filters are new.

With any diesel I know of filters are always very important. You should always replace them whenever a fuel issue raises it's head first. Unless something else is perfectly obvious.

I once attempted an alternator rebuild in a hotel room...

__________________
"Senior Luna, your sense of humor is still loco... but we love it, anyway." -rickymay ____ "Your sense of humor is still loco... " -MBeige ____ "Señor Luna, your sense of humor is quite järjetön" -Delibes

1982 300SD -- 211k, Texas car, tranny issues ____ 1979 240D 4-speed 234k -- turbo and tuned IP, third world taxi hot rod

2 Samuel 12:13: "David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has put away your sin; you shall not die."

Haha, well I frankly hadn't even considered that!

I PMed a source of infomation.

In the case of the Fuel Supply/Lift Pump you have to fabricate something to hook up a Gauge on the Liftt Pump and when you do even with a Liquid Filled Gauge the Needle bounces around considerably making it hard to get a reading.
On the 617 type Lift Pumps this makes it easier just to remove the Lift Pump and take a look insde to see if the Piston is stuck or badly scored up or if the Spring is broken.
Along with that you can purchase the Valve Kit and scrounge up the 5mm O-ring that does not come in the kit and rebuild the Pump.
The Kit when Fastlane supplied it was less than $20 and can also be had at the Mercedes Dealer (remember the kit has no O-ring in it for the little PLunger the Lift pump).

It may be that simply cleaning the Valve Area would help.

There is several rebuild threads on the 617 type lift pumps and 2 on the 603,606 type Lift Pumps (kits cost more for these).

Note: The Gasket between the Pump and IP does not come in the kit either.

In short rebuilding the 617 type Lift Pumps is easier than Trouble shooting them.

A leaking Hand Primer should be repaced by a Real Bosch one.

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__________________
84 300D, 82 Volvo 244Gl Diesel

Well, I have looked at pretty much everything in the fuel system (at least the set up I am running) and there are only 2 things that I think could be causing this problem:

1) IP throttle rack jammed (or something like this) I think maybe inside my IP is just gummed up. As people have suggested, I am trying to use solvent on the inside of it. I may also remove non-calibrated parts of the IP to see what it looks like.

2) My lift pump is not so hot. If 1) doesn't prove to be the issue in short time, I will try to source a new or used lift pump or rebuild mine.

Either way, I will update this when I think I have found the solution or if I have any new information, I think 1 or both of those things will solve my issue, but I will put up what it finally is, so if people stumble upon this thread having a similar issue, they will at least know what the issue was in my case. Much thanks to everyone who has contributed. I hope it won't be long before I figure out my issue. Unfortunately, I am leaning toward 1) for a number of reasons. If anyone is curious, I could try to compile why I think it is 1), but I have a strong hunch. Also, if anyone has ideas for easy ways to clean the IP beyond what was said in the link I posted or in this thread already, I'll try anything I'm convinced isn't going to be damaging.

I woud not recommend laquer thinner as the soaking agent if I thought anything internal on your injection pump or lift pump would be damaged from it. I never recommend anything that I feel could cause damage.

From your description of the relief valve flowing fuel and then stopping. I would soak and if that did not correct it then rebuild the lift pump. As you mentioned you are feeding the lift pump from a container. So it has a known good and adaquate fuel supply.

To get clear of your concern on the rack in your injection pump. After cleaning have someone keep priming the primer pump and see if the car will run. The primer pump must stiffen up as the relief valves opening pressure is near.

Typically there is a sort of squeel when it opens. The primer pump uses the valves in the lift pump remember to prevent backflow when pumping. So the resistance building to push the primer pump as you pump it and build pressure is required..

The lack of any increasing pressure resistance is usually either fouled valves in the lift pump or an open relief valve. You are in the process of learning all about the fuel system. This will allow you to help others as well as yourself.

I had to change my on site identification as my computor was seriously hacked into awhile ago. I have over four thousand posts under my old ID.

You might be surprised on how many times folks on here have a "strong hunch" without the slightest bit of supporting data. They run around and around and they spend all kinds of time and money until their "strong hunch" was proven to be incorrect.

Or, they get rid of the vehicle without solving the problem. They were not giving up on their hunch.

i'm gonna bet that its your lift pump that is causing the problem. The valves can become "sticky" from nasty wvo. The kit to rebuild the valves is cheap and its a relatively easy job.

It is also possible to clean them out a little bit if you want to go that route but either way you're going to to have to pull it off so i'd just go for the kit if i were you.

__________________
Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"