1996 e300 diesel, no power noisy - Page 2 - PeachParts Mercedes-Benz Forum

GregMN · #16 03-03-2013, 01:25 PM

If air in the fuel line and fuel line restriction has been eliminated:

Either the throttle position sensor is flaky or the drive-by-wire electric fuel control valve. I was having intermittent hard starting and my wife was having no response to throttle input for the first mile (it never happened to me). I replace the fuel control valve (at 310k) and have not had the problems since.

stubborn66 · #17 03-03-2013, 08:50 PM

The throttle postion sensor is a potentiometer but I cant find a procedure to graph it. Does anyone know the schematic for it?

Also, the electic fuel control valve, is that located on the back of the pump?

thanks

GregMN · #18 03-03-2013, 09:30 PM

Pelican Parts - Automotive Parts and Accessories - Porsche & BMW

Side of pump. Make sure you replace the o-ring too.

http://www.peachparts.com/shopforum/attachments/diesel-discussion/101029d1333075023-96-e300-wont-start-w210-ip-1.jpeg

http://www.peachparts.com/shopforum/attachments/diesel-discussion/101030d1333075035-96-e300-wont-start-w210-ip-2.jpeg

stubborn66 · #19 03-03-2013, 09:38 PM

http://www.peachparts.com/shopforum/attachments/diesel-discussion/101030d1333075035-96-e300-wont-start-w210-ip-2.jpeg

What is part number 165 in this picture, that is what I was thinking, I am not on my shop computer right now so I cannot see All Data but that is what I was thinking.

I am going to figure out how to graph the TPS and look for drop out but I am leaning away from that at this point.

Thanks for all of you input

GregMN · #20 03-03-2013, 10:12 PM

I don't see a 165, but 155 is the fuel heater.

stubborn66 · #21 03-04-2013, 08:23 PM

155 is the part I meant, sorry, is that anything other than a heater?

Tonight I pulled the fuel control valve and checked the connection, made sure the valve moved freely, the check ball is loose and not gummed up. test drive, no difference.

The more I tinker with this I seem to notice that it runs good at lower RPM but from 3K on up it gets noisy, looses power and the max RPM I can get is just over 4K. I am now wondering if the governer in the front of the pump can be the issue. I know there is a pair of weights in there but I dont know much else. As far as I know the pump has never been off this engine. Is the governer a common failure item?

Thanks

stubborn66 · #22 03-05-2013, 08:24 PM

I found a test procedure for the vacuum transducers so tonight I ran that and both passed that test. Even though I dont believe the EGR would limit fuel flow I thought I would try it since I found it.
I also switched the position of the two valves while I had them out. I took it for a test drive and it revved right up to red line in first gear be when it shifted into second gear it would not rev up past 4K again. It now almost seems as if something in the shift control is limiting it, is that possible?
I now think it is running real good up to about 3K rpm and then gets sluggish from there up.

Pabster · #23 03-08-2013, 09:21 PM

The is worth some thinking. I bought my 97 300D and it started well, but when the engine got warm, the car didn't respond well from a stop. It would chug slowly, build up a little speed, then start driving normally, but the engine was really revving at this point. The car was not safe to drive in traffic. Also the engine would shake the car at a stop.

Ha, ha, I got it cheap! But I knew I could trouble shoot it and did.

Delivery Valve Seals and o ring replacement. Once replaced, the car drove like a champ and the way its suppose to. I also changed the fuel lines, replaced the fuel filters, engine mounts, blocked off the ERG, cleaned the manifold, engine chambers...etc.

Lets just say that the big issue was the delivery valve seals and o ring replacement. After that fix, I marveled at how well my car drove. So its worth looking into it and the parts are cheap.

Pabster

stubborn66 · #24 03-13-2013, 08:03 AM

Hi, thanks for the input. I have changed the fuel lines, and the O rings on the shut off valve and the lift pump, as well as the fuel return lines. I have also pulled and disassembled the fuel pump and checked to make sure the check valves seat. What do you mean by the "delivery valve seals"? Teh PO replaced teh injectors and I suspect he may have chosen the cheapest injector he could source.
Also, at this point the marble noise has gone away but it sitll does not quite run right in that it still will not wind up as it should. I have learned that if I only give it 3/4 throttle it will come up through the rpm range and shift as it should and run pretty good. It will not run as it should if I bury my foot in it.

connerm · #25 07-23-2013, 09:44 AM

I suggest bypassing the fuel heat exchanger. Just bypass it and see if it works any better. There is a tiny thermostat in there and maybe it has stopped working properly or is plugged with junk. This is the first place fuel enters the engine compartment after leaving the tank. This is a very simple test that can be done very easily with an old hard fuel pipe, some fuel hose and hose clamps. Also, make sure fuel pipes on lift pump aren't switched - the short pipe should be farthest away from the injection pump.