1999 E300 TURBODIESEL Injection Pump Repair Problem - PeachParts Mercedes-Benz Forum

E-Classy · #1 03-21-2007, 09:42 PM

Well, it's finally done! I've replaced all six sets of Delivery Valve O-rings and Copper Seals on my 1999 Mercedes-Benz E300DT Injection Pump. There's only one problem - she won't send diesel fuel through the system when I crank the engine...

After the installation of the new Delivery Valve O-rings and Copper Seals, I tightly connected the metal fuel lines at the Injection Pump. I then "cracked open" the metal lines at the Injectors (see photo below) and placed a plastic cup at each of the open fuel lines, being careful to cover the exposed Injectors with clean paper towel. The idea of placing the cups was to collect any contaminated and dirty diesel fuel - left over from the Injection Pump repair. I figured that it was worth the extra step, for the sake of "peace of mind" driving and long-term reliability – not to mention the cost of replacing one or more bad Injectors!

I've noticed that, during the repair process, small metal particles from the Pressure Valve Holder threads as well as broken up pieces of black rubber from the original (seven plus year old) O-rings had lived inside each of the pump's six Delivery Valve cavities. I thought that by flushing fuel through the Injection Pump and out through the metal fuel lines, just before the Injectors, would significantly reduce the possibility of clogging one or more of the Injectors with this contaminated debris.

After several minutes of turning the engine over, but stopping repeatedly to allow the Starter Motor to cool, I noticed that the car initially turns over only five to six times and then only once afterwards. This process consistently repeats itself, after I’ve let the car sit for a few minutes between cranking attempts. I don’t know why the car does not “turn over” continuously until the Smart Key is removed. The only thing I can attribute to this phenomenon – is that the battery is low, and even though I’ve boosted the car during this process, it still exhibits the same pattern of short cranking, followed by a single turning over of the engine. Perhaps I need to add more diesel fuel to the fuel tank? There is currently only nine liters (approximately 2.37 US Gallons) of ULSD fuel remaining. Maybe the system is partially gravity fed, especially when most of the original diesel fuel had been drained from the lines - during the Injection Pump repair activity.

I would welcome any and all ideas on this one – especially after I’ve carefully followed every step during the Injection Pump repair process to ensure a reliable and successful repair of the originally leaking Delivery Valves on the Injection Pump.

TMAllison · #2 03-21-2007, 10:18 PM

I suspect you are attempting to let the car "auto start"?

To re-prime the system, you need to manually hold the key and crank 30 secs, stop 10 secs, crank 30 more. You can do that for 3 sycles, then let the starter cool and battery recharge.

Once it seems like it is catching, keep cranking until you are positive it is running or you will start the cycle all over. It wont hurt the starter to keep at it a few secs longer once you "think" it has caught.

E-Classy · #3 03-21-2007, 10:46 PM

Hi Terry,

Yeah, I see what you mean. I actually didn't know about the Mercedes auto start feature (turning the Smart Key fully clockwise and then releasing right away) until two months after I bought the car. I had mistakenly let go of the Smart Key right after turning it all the way clockwise – immediately after the Glow Plug coil symbol had turned off. The car continued to automatically turn over until it started! I thought that was pretty cool at the time – and still do!

In this instance, I insert the Smart Key then hold it in the far right/clockwise position indefinitely. But it just turns over five or six times and then STOPS dead!

The only way for it to turn over again - is to remove the Smart Key completely and go through the process again. But this time it will only turn over once. I then must wait a few minutes (at least) for it to crank again.

I had bought one of those Trickle Battery Charges (for 12 volt lead acid batteries), but I'm scared to use it - as my car's battery is quite new, less than a year old. I’ve read stories of damaging the battery by using one of those devices. The Trickle Battery Charger I have is 1.5 amps, so I guess it should be safe to use on my new Mercedes-Benz 12 volt battery.

TMAllison · #4 03-21-2007, 10:50 PM

Sounds like the battery is low and the ECU is interrupting the start to save your battery.

Can you jump it with another car?

E-Classy · #5 03-21-2007, 11:12 PM

Terry,

Tried for over two hours, earlier today - to no avail. The car kept on repeating the same pattern again and again... Just five to six "cranks", then nothing. Reinsert Smart Key, one more engine turn...then nothing. I have to wait a bit (at least two minutes) BEFORE I can try again. VERY frustrating, to say the least!

TMAllison · #6 03-21-2007, 11:17 PM

And also makes it very difficult to re-prime.

Suggest you try your charger. Disconnect positive and neg cables, pop vents and charge overnight then give it a go.

Mine will let me crank continuously until I run the batt down. Not sure why yours wont.

michakaveli · #7 03-22-2007, 02:31 PM

The best thing to do is to have the vehicle jumped off of another vehicle w/ a decent charging system and some solid jumper cables. These engines draw A LOT of current when cranking. I wouldn't waste anymore time cranking if you don't have the vehicle jumped, you'll just ruin the batteyr by completely discharging it. Can you tell I've been through some starting issues before??.

Also when it is jumped, let the glow plugs warm up, wait say 20 seconds after the lamp has gone out, and then begin to crank. Once it catches it will start up smoother and easier once proper fuel has been delivered.... Just some tips...

rackley · #8 03-22-2007, 03:43 PM

You need another vehicle, running, with jumpers connected to your vehicle's car. If you really drained most of the lines, you're going to be cranking for quite a while. The system WILL self-prime,but it will take a LOT of cranking. With just a trickle-charger you really need it let it sit overnight before starting to crank on it. With another car running you should let it sit and charge for a good 15-20 minutes if the battery dies on you.

The ECU will stop you from cranking the engine when your battery gets too low, it won't run until the starter clicks like a normal car.

raMBow · #9 03-22-2007, 09:26 PM

I think you always have to turn it all the way off before cranking.

Not certain about the MB, but on my brothers old jetta, we tried jumping it and revving the other engine and burned out all the GP's then it really would not start, just a thought and not even certain it applies in your case.

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