300 SDL delivery valves/injectors - PeachParts Mercedes-Benz Forum

gallaj · #1 10-20-2007, 01:33 AM

Hello everyone. I want to say that the forum is very helpfull. I recently just got a 300 sdl. When I got the car it was a little dark. I really liked it a lot, and really did not pay any attention to any leaks. Anyhow, after i got the car home I realized that delivery valve # 3 was leaking fuel. I did replace the O rings on all of them and also the cooper washer. All of the sudden the car was working with 5 CYL. I openned the delivery valves again because someone told me that the delivery valves can be adjusted. Now it is working with 6, it shakes less but is no where close to sounding like it did before I put my hands on it. The car also smokes and than when it accelerates it does not. I went ahead and replaced the injectors but no results. I dont know what to do anymore...I tried to take to a shop in town, but as soon as he heard that I had messed with the delivery valves he would not touch the car... The mechanic thinks some dirt must have gone inside the PUMP..My question is does anyone know any liquid that i can pure into the PUMP and maybe have it cleaned. Or what could it be ?

gallaj · #2 10-27-2007, 08:22 PM

I did remove all of the delivery valves one more time, and replaced the copper washer and the rubber O ring to see if I did anything wrong the first time. Now, the smoke went away but delivery # 3 does not have any pressure or it does get pressure at high RMP. It seems like the Engine is missing at Idle and it gets better at high speed. Also, the other thing that concerns me is that I am getting AIR in the system from somewhere. I see bubles in the return line. Does anyone have any idea where there air might be coming from. Could this be a IP timing issue.. The car ran fine before. Please help...

TMAllison · #3 10-27-2007, 09:40 PM

OUCH.

Sounds as if you have messed with the valve elements inside the DV holder?

Its the little needle like device that the spring sits on. It shouldn't be removed nor should the cylinder below it be fiddled with.

If so, its probably going to need to be re-calibrated by Bosch.

Are you torquing to 30NM, 30Nm and finally 35Nm?

gallaj · #4 10-28-2007, 03:52 PM

Thanks for the response. I torqued it to 30nw. I was affraid that was the reason behind everything. I did not even get to enjoy it for a bit. Anyone has an idea how much is the charge for a recalipration.

Maxbumpo · #5 10-29-2007, 08:28 AM

I think your problem is not serious, you simply need to get the delivery valves sorted out. For each valve, I'd recommend you replace the washer, spring, and O-ring.

Remember: CLEAN CLEAN CLEAN!!! Any junk that enters the system here will go downstream directly to the injectors and clog them. Use brake cleaner and toothbrush, then compressed air.

Remove one valve at a time, 'rebuild' it with washer/spring/O-ring, install and torque correctly (tighten to 30 Nm, loosen and repeat, then loosen and torque to 35 Nm and lock down). After each valve, start the car and see if the problem is fixed or if the injection pump is making a new racket. If the IP starts making a new racket, loosen that delivery valve and re-torque using above procedure (sometimes the IP body gets warped when tightening down the delivery valves).

No, your problem is not an IP timing problem; usually the IP only needs to be timed once, when the car is built, and keeps time perfectly for the life of the engine.

gallaj · #6 10-31-2007, 12:19 AM

Thank you for your response. Will try to change the springs also and will post the results.

Maxbumpo · #7 10-31-2007, 07:13 AM

Just read that you've also changed the injectors. Do you still have the old? If the new injectors were not a balanced set (opening pressures adjusted so that they all fall within a 5 bar range) then your idle may be rough regardless of anything else you do. If you still have the old, I'd put those back in. You may want to have a Bosch shop test them first and reset the pressures to make them a balanced set (or do same with your new injectors if the old are already gone).

gallaj · #8 11-10-2007, 11:43 PM

I ended up taking the car to a Diesel shop. The mechanic told me that I had come very close in damaging the IP. Apparently I had pushed sideways the niddle on delivery Valve # 3. I just got it back the other day and is running smooth again. I beleive I did removed more than i should have. Should have read the forum before started doing the work. I would also recomend in JAX, FL to take your diesel to ROYS DIESEL. Thanks everyone for all your help...