My new/used MB -1987 300TD wagon- PICs - PeachParts Mercedes-Benz Forum

1stbenznc · #1 01-19-2010, 10:53 PM

Hey everyone -
I'm glad to have found this site. Such great info and insights on all topics!

I just bought a non-running 1987 300tdt with 143k. The guy/mechanic that sold it to me said that there IS fuel coming out of the lift pump (he replaced it), but nothing coming out of the injection lines to the injectors - I've read a bunch of threads about it and different ideas to diagnose it or fix it. He didn't seem to know too much about diesels and was going to part out the car

!! I hope I can get it running,..... and it does run, shift, brake, etc

Attached is a picture from earlier this week when I got her home. It was a several hundred mile trip each way.....I hope it was worth it. I bought it for $1500 and will soon know if i paid too much, or was a decent price. I spent more on toll roads (4 axle) than I did motel and diesel (all the way on veg oil in the Excursion)

I will be checking the return line for fuel flow first, bleeding air next, checking the banjo fuel return bolt after that (not sure if mine is the serviceable one) to check the spring length. Not sure where the vacuum lines to the shutoff valve is either to check?? pic of it??? Does my car have a primer bulb?

Worst case, I did find a good used IP for $200 that I bought the day before I bought the car. I hope I don't need it, but it is nice to have an extra.

My plan is to update the look a little (94-95 style) and covert to straight oil. Lets see how she runs though first!! I look forward to spending many nights here learning about the car and buying parts. I will keep you all posted. Thanks -Michael

Jeremy5848 · #2 01-19-2010, 11:12 PM

Congrats - potentially a very good car at a good price. Hope you can get it running. Lots of folks here can help you with the IP. Make sure the car is running well on diesel before changing it to veg oil, you don't want to introduce any more unknowns.

layback40 · #3 01-20-2010, 12:57 AM

Great looking car!! You have done well. I am sure you will find the fuel problem is minor. It looks too good to have major problems.
I dont think that car will have a prime pump.
Many on here dont agree with this, but I have had it work a couple of times (I have a 2.5 na version of your car).
If you disconnect the return line at the secondary filter and connect a tube to the filter end & run it into a bottle. You can then carefully pressurize the return line to the tank with a regulated air hose. You will hear the air coming out the tank breather, despite this, in time it will pressurize the tank a little. This will force fuel from the tank up through the lines and you will see it flow out of the hose into the bottle. Initially you may see air bubbles, in time the air will bleed out. Be careful if you remove the air hose as the fuel will flow backwards through the return line & make a mess. Have a friend take the filler cap off the tank before stopping the air. This should allow you to bleed the fuel system without too many flat batteries.

Aquaticedge · #4 01-20-2010, 12:58 PM

I paid a lot more for my 87... so, you got that at a steal imo. these are Awesome cars indeed.

1stbenznc · #5 01-20-2010, 03:12 PM

We'll see if it is a good deal soon enough. I will do some diagnosis right now and let you all know what happens, and hopefully what was the culprit is. I will try to bleed the system of air too as I don't know what the guy before me did when he replaced/fixed the lift pump. Sounds like you may need to crank it over a lot unless you fill any voids with diesel (fuel filter replacement etc). I have a jumper box or may need a car and jumpers nearby.

I would love to hook up a remote starter button. I did not see how to do this here for this car. This will really help the back and forth from the engine to the ignition each time. Does anyone know how to do this or is there a DIY?

1stbenznc · #6 01-20-2010, 03:14 PM

Quote:

Originally Posted by Jeremy5848

Congrats - potentially a very good car at a good price. Hope you can get it running. Lots of folks here can help you with the IP. Make sure the car is running well on diesel before changing it to veg oil, you don't want to introduce any more unknowns.

Absolutely agree....

babymog · #7 01-20-2010, 04:38 PM

The wires to trigger the starter are on the inner firewall just forward of the brake booster (three wires in a plug).

bustedbenz · #8 01-20-2010, 04:40 PM

Quote:

Originally Posted by layback40

This should allow you to bleed the fuel system without too many flat batteries.

A couple years ago, I ran my 300SDL completely out of fuel. Sucked the tank dry, air in every line, filter canisters empty, sitting on the side of the road, *empty*.

They brought me about 10 gallons of fuel from home in containers. Dumped it in the back, got in, and cranked. This was compliant with the recommendation of the owners' manual -- and it was dark, and we didn't feel like pulling filters off, etc. We always keep batteries in top condition so it was relatively pain-free.

Obviously starters aren't designed for continuous abuse. However, we figured once or twice in its lifetime probably wouldn't kill it, esp. since the book says to do it this way. The owner's manual says to floor the accelerator and crank for up to 60 seconds until the engine is running, and doing so will self-prime the system.

They were right. My dad timed it while I cranked consistently -- we were afraid that stopping to let the starter rest might cause us to lose ground -- I've forgotten the time but somewhere between 30 and 45 seconds, the thing lit off and kept running.

My point in posting is that if the IP is delivering fuel properly, which it may well not be -- one 60-second crank will do all the "priming" good that can be done. If everything works as it should, I've demonstrated with my personal engine that 60 seconds of cranking or less is sufficient to prime a completely dry system.

If there are methods (filling the filter canister in advance, etc) to minimize the starter wear, then that's all to the good. I encourage it. My point is that 60 seconds is a good worst-case "it would have started by now if it was going to" mark. In my opinion. I'm sure somebody here has proved that it doesn't work but that's my experience.

1stbenznc · #9 01-20-2010, 10:51 PM

Quote:

Originally Posted by babymog

The wires to trigger the starter are on the inner firewall just forward of the brake booster (three wires in a plug).

Thanks- so does some type of trigger button just plug into it? Where can I buy one?

1stbenznc · #10 01-20-2010, 10:54 PM

Quote:

Originally Posted by bustedbenz

A couple years ago, I ran my 300SDL completely out of fuel. Sucked the tank dry, air in every line, filter canisters empty, sitting on the side of the road, *empty*.

They brought me about 10 gallons of fuel from home in containers. Dumped it in the back, got in, and cranked. This was compliant with the recommendation of the owners' manual -- and it was dark, and we didn't feel like pulling filters off, etc. We always keep batteries in top condition so it was relatively pain-free.

Obviously starters aren't designed for continuous abuse. However, we figured once or twice in its lifetime probably wouldn't kill it, esp. since the book says to do it this way. The owner's manual says to floor the accelerator and crank for up to 60 seconds until the engine is running, and doing so will self-prime the system.

They were right. My dad timed it while I cranked consistently -- we were afraid that stopping to let the starter rest might cause us to lose ground -- I've forgotten the time but somewhere between 30 and 45 seconds, the thing lit off and kept running.

My point in posting is that if the IP is delivering fuel properly, which it may well not be -- one 60-second crank will do all the "priming" good that can be done. If everything works as it should, I've demonstrated with my personal engine that 60 seconds of cranking or less is sufficient to prime a completely dry system.

If there are methods (filling the filter canister in advance, etc) to minimize the starter wear, then that's all to the good. I encourage it. My point is that 60 seconds is a good worst-case "it would have started by now if it was going to" mark. In my opinion. I'm sure somebody here has proved that it doesn't work but that's my experience.

Cool - I will remember that and give it a try. My battery is already weak and I only had enough juice, after messing with it, for a 30 seconds before it started winding down. Since it is in the garage I think i will invest in a small batt charger tomorrow

barry123400 · #11 01-20-2010, 11:23 PM

Or remove the air cleaner and spray some wd 40 into it. With someone cranking. It should start and by judicious application of more wd 40 keep running at least until fuel is up and air driven out of the base of the injection pump.

These starters are not really designed for continious cranking like mentioned. You may or may not get away with it. It also may take a really good battery to last for 45-60 minutes of cranking. I would try the spray.

swogee · #12 01-21-2010, 01:15 AM

As mentioned in the other posts, if indeed the fuel system has lost prime the engine will have to be cranked for at 30 seconds multiple times. The accelerator pedal will also have to be floored while the cranking occurs. I would suggest having another diesel's battery (or two gasser batteries) connected in parallel (with 4 AWG jumper cables) with the 300TDT's battery while cranking to keep the charge up. Also don't exceed 30 seconds of cranking time to avoid burning out the starter. If the fuel system prime has been lost, the engine will run rough until the air is out of the system.

-Steve

babymog · #13 01-21-2010, 08:47 AM

Quote:

Originally Posted by 1stbenznc

Thanks- so does some type of trigger button just plug into it? Where can I buy one?

You can buy the clamp-on remote start button, a couple of smaller alligator-clips will fit the un-plugged pins.