87 603 diesel runs rich - PeachParts Mercedes-Benz Forum

nulu · #1 07-01-2012, 12:35 AM

Ok guys ,ive just installed a used 603 engine in a 1987 wagon, its compression was all over 420lbs every cylinder , the original engine threw a connecting rod thru the side ,my used engine runs rich at above idle speeds, anyone have any ideas why or what to check, it wont stay idling, only if i put my foot slightly on the gas, black smoke is coming out at exhaust and seems like its rattling , from too rich? could an injector do that? or does the airflow meter cause this?it is running evenly,i inspected alda , but didnt see anything obvious.

vstech · #2 07-01-2012, 01:23 AM

could be the air dam/egr flow valve.
disconnect the elbow feeding the turbo, and see if it still does it.

Diesel911 · #3 07-01-2012, 02:59 AM

Quote:

Originally Posted by nulu

Ok guys ,ive just installed a used 603 engine in a 1987 wagon, its compression was all over 420lbs every cylinder , the original engine threw a connecting rod thru the side ,my used engine runs rich at above idle speeds, anyone have any ideas why or what to check, it wont stay idling, only if i put my foot slightly on the gas, black smoke is coming out at exhaust and seems like its rattling , from too rich? could an injector do that? or does the airflow meter cause this?it is running evenly,i inspected alda , but didnt see anything obvious.

If you had one bad Injector that was lets say not atomizing well it would kind of puff the Black Smoke.

If you loosened the Fuel Injection Hard Line Nut at that Injector the Black Puff of Smoke would stop.
Also the Engine would only run slightly if at all worse.

Loosening the Nuts on good Injectors will have a obviously worse effect on the running of the Engine.

On Mercedes Engines that have the Inline Fuel Injection Pumps the Injector does not control the amount of Fuel Injected. The Injector sort of acts as a pressure relief Valve and controls the pressure the Fuel is injected at.

nulu · #4 07-01-2012, 08:32 AM

im going to check pump timing first, then will drop downpipe to see if i have a retriction in exhaust.

vstech · #5 07-01-2012, 02:01 PM

"running rich" is an indication of too much fuel or too little air.
if the air filter is clogged, it'll run rich. if the EGR flow valve is closed it'll run rich. if the alda is stuck open or broken, or adjusted heavy, it'll run rich. if an injector is dumping fuel in a wide open configuration, it could run rich...

nulu · #6 07-02-2012, 01:08 AM

Thanks folks, ill be back on the car weds, ill repost what i find,

locry · #7 07-02-2012, 05:43 AM

At what rpm is it idling? I always thought when diesels ran rich they'd speed up?

nulu · #8 07-16-2012, 11:17 PM

Finally had time to check timing on my motor its way off , ill retime to factory specs and we will see how she runs!, anything special needed to r and r pump to retime?

nulu · #9 07-27-2012, 12:41 AM

Regarding my rich running , it was injection pump timing off, and cam timing off 1-2 teeth, with a glow plug inop, i bought a used motor from pick your part for 250.00, compression was good, now its running good , smooth,thanks for yoyur replies guys

vstech · #10 07-27-2012, 02:23 PM

... 2 TEETH off?
I think the valves would hit with that much splay... that's 36DEGREES!!!

nulu · #11 07-27-2012, 11:25 PM

Well im hoping it was only 1 tooth off, it was advanced, i think someone turned the engine backwards , the upper rail was broken,i measured compression at all cylinders at 420-430 lbs of compression, engine only cost me 250 .00 at pick your part, after sorting out timing and injection pump off its quiet and no longer smokes , rattling gone etc, will fine tune this week.

nulu · #12 08-05-2012, 08:26 PM

Still had a rattle , turns out a center piece of right upper guide was still down near the crank sprocket, couldnt see it untill cam gear taken off ,found my source of rattle when hot, like something was going to come apart, figured ill take oil pumo inlet off to check for plastic , and it was full of plastic , had oil pressure , but gauge was jumping , so its going back together , and replacing head gasket now that engine runs good, idles good , starts easy, excellant power , not too bad for $250.00 pick your part motor, just a lot of time to sort it out, new to this diesel stuff but paying off, thanks for ideas . remember to always remove the oil pump inlet to check for debri, what i found could of damaged engine.