'85 300TD dying out - Page 2 - PeachParts Mercedes-Benz Forum

StaggerLee · #16 04-06-2012, 12:50 PM

If you have bubbles forming in the prefilter when you push the primer pump, you have air leaking into the system.

kerry · #17 04-06-2012, 12:59 PM

If you had the same problem when running it on a separate container of diesel, the issue isn't in the fuel line between the filter and the tank. Given your tests, I'd try replacing or rebuilding the lift pump.

Biodiesel300TD · #18 04-06-2012, 02:02 PM

Quote:

Originally Posted by kerry

If you had the same problem when running it on a separate container of diesel, the issue isn't in the fuel line between the filter and the tank. Given your tests, I'd try replacing or rebuilding the lift pump.

I agree with Kerry. These don't fail a lot so it's pretty easy to find a good used one from the junkyards. It's a pretty easy swap, but be ready for a fair amount of oil to drain out of the IP, maybe a quart at most.

Graplr · #19 04-06-2012, 04:53 PM

Quote:

Originally Posted by kerry

If you had the same problem when running it on a separate container of diesel, the issue isn't in the fuel line between the filter and the tank. Given your tests, I'd try replacing or rebuilding the lift pump.

The LP is still the possible culprit but he said he hooked up his "new" diesel tank to the prefilter hose. So the problem could lie in a hose connection at the prefilter or in the manual pump. He said he notices bubbles when priming with the hand pump.

I would start by trying a new hand pump. Also did you check for air bubbles when you ran the fuel from a tank under the hood?

Stono-see-um · #20 04-07-2012, 11:07 AM

After reading some of the previous posts, I didn't mention I do get that "squish" sound after a few pushes of the prime pump. Seems like once it starts to build pressure, its starts the squish sound. I don't just get a couple bubbles in the filter, it looks like I am blowing bubbles in there!

I drained the tank a couple days ago, cleaned the screen and blew out the supply and return fuel lines yesterday. Put 5 gal of fresh dino in there, bled the injector lines and took it for a spin. I thought for a brief minute that fixed it. But no, on the way back it started to sputter again.

I noticed someone mentioned the crush washer in the prime pump. Is this something NAPA or the like would have?

I planned on going to get a new trans filter and replace that while I am under there, so I could take that crush washer with me when I go.

Oh Graplr, to answer the question about the new tank of fuel under the hood, it was shaking so bad from the engine, I couldn't really tell if I was getting bubbles then.

The PO does have a couple parts cars I could probably get a new (old) IP from. All he asks is to pay him in beer!

kerry · #21 04-07-2012, 11:50 AM

Quote:

Originally Posted by Stono-see-um

I could probably get a new (old) IP from. All he asks is to pay him in beer!

Not on IP, a lift pump. Big difference.

Stono-see-um · #22 04-07-2012, 01:44 PM

Quote:

Originally Posted by kerry

Not on IP, a lift pump. Big difference.

Devil's in the details.

Stono-see-um · #23 04-07-2012, 02:03 PM

So... the Lift Pump is actually the Primer Pump??? Is there a rebuild kit, cause I'll tear that sucker down today?! Sorry if these are dumb questions.

I can't find anything in Peach Parts Fastlane for an '85 300TD! I have to search under a 300D. What gives?

kerry · #24 04-07-2012, 02:06 PM

Primer pump is attached to the lift pump (I think). Search on rebuild kit for lift pump. I'm not sure where people are buying the kit.

Stono-see-um · #25 04-07-2012, 03:30 PM

Thanks Kerry!!

Stono-see-um · #26 04-27-2012, 09:12 AM

It's been a while since I posted last, but I just got a lift pump rebuild kit in a couple days ago. I tore down the lift pump yesterday and found all kinds of nastiness in the lift pump. Almost looks rusty in there. A good bit of gunk, along with orange colored liquid. I am guessing water got in there from the fuel some how.
My next question is, are there any good cleaners for these lift pumps? I could soak it in carb cleaner or spray the crap out of it, soak it in diesel or I have a can of Diesel Purge, or Brake Cleaner? I don't want to use something that will harm any thing, but I am not too worried about harming the lift pump at this point.
If cleaning this thing up doesn't help, I guess I am going to try to find a spare used lift pump. I will be replacing the rubber fuel lines as well to the pump.

BTW, I think Mercedes Engineers in the '80's moonlighted as comedians in their spare time. Getting to the 2 bottom nuts on the lift pump is definitely a joke!!

Stono-see-um · #27 05-29-2012, 09:58 AM

Still no solution to her dying out. I did rebuild the lift pump, replace rubber lines, changed filters again. It is very odd. She will run like a scalded dog in the driveway, I take it out for a test run and it does OK for a couple blocks. Then it's right back to loading up/dying out, flaring/surging etc.

I think I am going to pull the muffler off and see if it is clogged. I have heard of similar issues being caused by a clogged muffler. Really grasping a straws here, but I would really love for this car to be back on the road. I have put too many hours and $$ in her the past year to give up now!!

barry123400 · #28 05-29-2012, 10:30 AM

Quote:

Originally Posted by Stono-see-um

My 85 300 TD keeps dying out on me. I have searched and read, searched and read, but cannot find a solution.
I have changed both filters, adjusted valves, bled injector lines and still she dies out on me.

Here is the situation. She is not my daily driver, so she sits a lot. I have to manually push prime it about 60 times to get her to start. She will idle all day long if I let her, but once I get her out on the road, she eventually bogs down and tries to die out. I pedal her back home and I start all over trying to get it to run. I have to pump the accelerator just to keep the RPM's up enough to keep from dying.

The last time I was bleeding the injector lines, I decided to find the ALDA, as I was curious where and what this mysterious thing was. I found it with no cover over it, like I have seen in pictures. The screw was very loose, so I just tightened it up using the adjusting nut. Could this have anything to do with it dying out?

NOTE: When I was bleeding the injector lines, I am not sure if all the lines bled out properly. Some bled a lot of fuel out, others not so much.

What direction should I be going with this? Should I be thinking about pulling the IP and breaking it down and rebuilding?

I purchase her about a year ago and have been steadily working on it here and there. Before I purchased her, the previous owner had the tank drained, screen cleaned and injectors swapped from another donor vehicle. He also ran a good bit of WVO/Jet Fuel through her as well.

Thanks for any and all help. Starting to get a little frustrated with it, but I enjoy figuring these unique beasts out.

A few small things I might try. Close the return fuel line from the injection pump off. If problem is gone then you at least have localised it.

Disconnect egr valve line and plug it. I do not know if the egr coming on at low rpm could tend to smother the engine this bad or not.

Make sure the crankcase ventalation system is really clear. As engine warms up perhaps increased contained blowby presure might be trying to shut the injection pump off.

These are just a few things I might do if I had a simular problem. No gaurantee they are what is wrong or will prove anything. They cost nothing but a little time to do though and may or may not indicate something.

Try not to get frustrated or mad at it. We stop thinking when we get emotional. I think your problem is minor in nature although perhaps not in effects.

From your description I would probably make sure the crankcase is not pressurizing first. A close second is the closing off the fuel return line. As you mentioned all lines did not produce equal amounts of fuel when bleeding. This to me might have been a slight clue. If the return relief valve is junked up with wvo stuff .As the fuel heats up an already sub standard fuel pressure in the base of the injection pump may drop further.

Closing off the return line from the injection pump will hurt nothing. I would also loosen up the alda screw again if the symptom only started right after you tightened it up. I think this is another possibility other than your situation being so warm up dependant.

Again though I know far from everything. What I do know is none of the simple tests I mention cost anything to do other than a very little amount of time. Last but not least at this point there is no indicator yet that you have a truly faulty injector pump other than the alda possibility or the relief valve perhaps. Both changeable components on the car if it where to become required.

Postscript. I just went back over some of the threads on your post. I noticed diesel 911 pretty well covered the same items. I will not delete my post as the difference in language one way or another might make a difference.

cirrusman · #29 05-29-2012, 11:14 AM

Quote:

Originally Posted by Biodiesel300TD

Please do, this is a good practice that gets missed in most posts. Posting what finally fixed the issue is very useful to future readers trying to troubleshoot their problems.

^X2

Graplr · #30 05-29-2012, 01:29 PM

Have you checked for air bubbles in the return line yet? I suggested in an earlier post to put clear (opaque) fuel line to check for air bubbles. Just get some 5/16" poly line from just about any parts store, Wal-Mart, Farm Supply, etc. It is often blue or pink and you can easily see fuel passing through with a flashlight. Rev the engine with the linkages and check to see if you have air.