mjr24

I just bought a CLS so I haven't been driving my SL55 as much.

I noticed a few weeks ago (I let the car sit for 2 days)....that when I started it the first time...the car would take a few seconds to start (almost like when starting your car after you have run out of gas...like there is no fuel in the lines). However, once it is started that first time....I can shut it right off and turn it back on and it starts up perfectly right away....and every time after that, until it sits overnight again.

This has become a pretty normal issue the last few weeks, though....where if I leave the car overnight....and then start it the next day...it's sputtering that first time.

Any ideas? I do need to replace my crankshaft position sensor....so not sure if this is related.

coldwell

will it misfire enough to set a code. If not try letting it run long enough to set a code. that will give you a direction to go. Possible coil.

superstar

Sounds like you are losing fuel pressure from the fuel lines when stays overnight. Check the fuel pressure before & after start..

mjr24

No, has never thrown an error code after this....

alx

this. your fuel rail is not holding pressure.

mjr24

Assuming that is the case....what are some possible problems?

I assume fuel filter......or fuel pump? Anything worse?

alx

Leaky injector is the most likely culprit. Dirty or malfunctioning.

carlsturm

If leaky injector you might see some black xsmoke in exhaust when you first start.

Nevertheless you should have someone check for presence of smoke at startup and what color.

How many miles on car?

overZealous1

yes, definately not keeping pressure in the line. can be a multitude of things though. injectors, pump getting weak or not holding pressure, injector seals, leak in line. any of these would do exactly what you are saying. a clogged fuel filter can do the same thing also. to further diagnose, turn ignition on a couple times first but don't start it. it will prime system and should start right up and no stumble.

mjr24

Will check it in next few days and see how it goes......car started right up today....didn't see any black smoke from pipes....may have seen a little white smoke for a few secs after startup...but went away.

Flyby

I'm having similar problem cars running funny for few seconds after start it ran perfect before then in December the fuel pump went on it and now when I start it does that and I smell fuel sometimes, i took it to dealer couldn't find anything wrong with it they kept it for a week

overZealous1

they could have not gotten a good seal on the fuel lines while replacing pump. leak can be small enough to evaporate before it can even create a drip, but still smell it, overnight it will drop pressure.

Flyby

Do you happen to know we're the fuel pump and filter are located on the sl55

overZealous1

It is basically above the rear end. Not super easy to get to.

Flyby

I have an rpm problem when at or between 1500 to 2500 rpms I watch and feel my rpms slightly twitching up and down causing the car to appear to be hesitating however if I punch it its fine you wouldn't think that would have anything to do with the fuel pressure dropping by having a small pressure leak

overZealous1

You sure it just isnt the sc engaging and disengaging? Fuel delivery problems happen high in rpms if idle is good and no leaks.

Flyby

Is that normal for the sc to do that is there maybe something wrong with the sc the only mod I've done was change the air filters to k&ns I rechecked them the other day to make sure they were seated properly although the sc engaging and disengaging would deffenetly fine you that feeling

Flyby

I saw your earlier statement in the tread do you think it could be the fuel filter

overZealous1

the sc has a clutch. i do not know the exact parameters the ecu looks for to engage it, but, it is right in that rpm range. you can definately feel when it engages. add aftermarket pullies and it amplifies.
most common symptom of a bad fuel filter is hard starting. another is running lean in upper rpms.

Flyby

What kinda hp are you pushing with all those mods that's pretty impressive looks like you've dropped a pretty penny I really like the r230 it has a lot more character than the newer body styles wouldn't mind doing some seriouse stuff to it thought about renntec and have been looking at some pretty Kool body kits considering its only a weekend toy can probably get away with some crazy stuff ill have that fuel filter replaced and will have them look at the entire fuel system at mb their already worried about it because they couldn't find anything wrong with it on the second round but I don't think they went that deep maybe this time they'll figure it out really appreciate your knowledge on the subject

dfrat

Did you ever resolve this? What was the exact problem that you found? What was the solution? Thanks.

Eprestige1

did you ever resolve this yourself? I noticed nobody replied, but Im having the same issue...