87 300D starts then dies immediately... - PeachParts Mercedes-Benz Forum

vstech · #1 09-10-2010, 10:25 PM

ok. I got the car home. cleaned off the filthy motor, and changed the oil and flushed the radaitor and block then added laundry detergent to the coolant, and filled with water to degrease in preperation for a superflush/citric flush.
then started the car to drive it off the trailer, backed it down smoothly, drove it around to the side lot, and turned it around to back into a spot, and it dies.
I restart it, and it dies again and again.
I change the fuel filter thinking there's maybe a clog, even though the prefilter looks pretty clean just a tad of gunk in there. the fuel flows smoothly out the banjo as I swap in the new filter, and rapidly fills the filter. I tighten it up, and it makes no change...

any of you 603 gurus wanna chime in with suggestions for tomorrow's diagnosis session?
pppplease?

BoiseBenz · #2 09-10-2010, 10:36 PM

Either fuel/air leaks or wonky vacuums? Disconnect the shutoff line?

sixto · #3 09-11-2010, 02:33 AM

Are you getting fuel to the injectors?

Shut-off lever stuck down; disconnect vacuum line to actuator to test.

Clogged cat; remove plug in #1 exhaust runner to test.

Open check valve in IP return; clamp return hose to test.

Sixto
87 300D

vstech · #4 09-11-2010, 10:00 AM

I had a helper start the car, while I inspected things.
the start lever pops up into the run position during glow, and stays there while it's running and after is dies.
it did have a LOT of smoke, so a plugged cat makes sense. THanks!

Bill Ladd · #5 09-11-2010, 10:34 AM

I had a pesky air leak on my '87. Would start and run a bit, then die. Look for fuel leaking anywhere along the delivery path. Mine turned out to be the hard clear line from lift pump to IP.

I have read here about, but have absolutely no experience with, defective fuel heaters as well. I isolated mine during diagnosis, but it turned out to be sound.

bustedbenz · #6 09-11-2010, 12:48 PM

How does it do when you crank it with your foot on the floor and then continue to hold high RPMS (maybe not redline, but see if you can hold it at 2000-2500 with your foot) rather than letting it die off at idle? Any different? Can't get it up that high? Have to fight it?

vstech · #7 09-11-2010, 09:48 PM

it was like this.
GLOW, Crank, start, maybe 5seconds, die. didn't matter floored, or feathered.
I pulled the plug. cranked right up. LOUD!!! like a freight train whistle!
ran fine, didn't die.
dropped the down pipe, and cut the inlet pipe off the cat... OMG!!!
SOOOOOOTTTTT!

I think a "evaluation" section of straight pipe is in order...

and I think an "evaluation" EGR block off plate is also needed...

I also pulled the crossover tube off the turbo, and checked it for plugged lines, it looks sooty, but not a thick residue like I've seen on other cars. I'll clean it out of course, but I'm surprised at how little is in the crossover tube.

vstech · #8 09-12-2010, 11:26 PM

ok, tonight I got it back together with the evaluation pipe welded in place, then drove it around to flush out the block with the detergent in there, and then parked it to cool down, and flush out. rinsed it really well, then opened the block drain and rinsed some more, then flushed through the heater core, went to refill, but had no G05... pause until tomorrow..
however, while on the drive, the temp gauge never moved from 40... crap. I looked on the head, and found several temp connections on there, all attached.
I'll short the center head one to ground and see if it swings the needle or not. HOPING it's the sender.