REALLY Hard starting.(sometimes)...rough idling
 

I recently purchased a 1988 560 SL that had been sitting about a year. I replaced the plugs, wires, rotor & distributor cap. It still idles a little rough, BUT the big thing is that sometimes it starts REALLY hard when warm. I'll pull in to a store, go to leave & crank & crank before it starts. Then the next time it will start right off??? One hint- sometimes it starts but seems to be running on just a few cylinders, then stalls. Any ideas?? Sometimes pumping the accelator seems to help, but I know that's it's fuel injected...

RE: REALLY Hard starting.(sometimes)...rough idling
 

if 117 got leaky injectors, it will take time to burn the fuel that was accumulated on the top of piston/s. it will run rough at start and eventually runs fine after a few seconds.

RE: REALLY Hard starting.(sometimes)...rough idling
 

It's not really that way. It idles rough pretty much all the time, sometimes worse than others. Starting the same way. Maybe 5 times, it will fire right up, then one time it just doesn't want to start. I'll drive a mile or so, park, come out in a few minutes & it won't want to start. the only other symptom is that sometimes it'll begin to start, then die. Then i really have a hard time with it.
Thanks for the input. Would a vacuume leak do that??

RE: REALLY Hard starting.(sometimes)...rough idling
 

vacuum leak only make the engine shake wildly.

RE: REALLY Hard starting.(sometimes)...rough idling
 

How was it running before you replaced the plugs, wires, rotor, and cap?

RE: REALLY Hard starting.(sometimes)...rough idling
 

It was running rough all the time. The tune-up smoothed it out for the most part, but it still is a little roug idle. The bothersome part is the hard starting...about 1 out of 20 times. I ran injector thru the gas tank, but that didn't seem to help. Would changing the fuel filters help?

RE: REALLY Hard starting.(sometimes)...rough idling
 

Replacing maintenance items never hurts. A clogged fuel filter can certainly cause those problems.

Gas gets really gunky after a year, especially if no stabilizers were added. Throw another can of Bud, er, injector cleaner in there when you replace the fuel filter. Use a different brand of cleaner. They all have slightly different formulas.

RE: REALLY Hard starting.(sometimes)...rough idling
 

/i think i found my problem..... I went to change the fuel filter and found that the gas line out of the filter was leaking. The car ran great when I first did a tune-up but then has been getting progressively worse. It finally started after about 10 minutes of cranking. I noticed a puddle under it & found the gas leak. Evidently it has been getting worse and finally showed itself. I'm sure that improper pressure to the injectors would cause my problem. Getting a new fuel line today.

RE: REALLY Hard starting.(sometimes)...rough idling
 

Hey, cool... that you found the problem, that is... I hope.

RE: REALLY Hard starting.(sometimes)...rough idling
 

#$&*&% I changed the fuel filter, fixed TWO leaky lines. Car started right up cold. Drove to the store, everything eas fine. Left OK. Next stop....wouldn't start.