Cold start problem - PeachParts Mercedes-Benz Forum

redbaronph123 · #1 02-09-2006, 01:38 AM

My car has always started right up without any fanfare eversince i got it. However, last sunday when our club had a funrun over a twisty and up and down road condition, my car started to act funny.

After arriving at the destination, we had breafast, and had some laughs over our cars, then around lunch time, when i started the car, it idled very rough as if its trying to keep itself from dying. Once the oil pressure gauge has pegged at 3 bar, it smoothens out, and off i went.

Driving down from the destination, the car performed rather lively, after being driven around in the city for more than a year, with this as its first outing for quite awhile.

Reaching home, i let it idle for awhile.. then turned it off. Now it is thursday here, and everytime i would start the car cold, the rough idle, almost dying situation always happens, and a lot of smoke billowing at the back. Pegging the oil gauge at 3bar after maybe 2 seconds, everything is fine. No power loss or anything.

What could be causing this? Did our funrun do anything to my engine. The funrun was mainly highspeed/high revving situations, trying to keep up with the gassers and ahead of the slowpokes. Did i loosen a lot of carbon buildup that it is affecting my engine??. .how come it only happens on cold starts? When in proper operating temp, killing the engine and starting it, it idles fine. It starts without any fanfare, i dont even need to step on the accelerator.

sorry for the long post, but i hope the story would provide some background before and possibly paint the situation for those who could help me out in troubleshooting this. Again, only on cold starts, once warmed up, the power is there, or whatever a 300D NA can give.

where should i start looking?? thanks in advance.

Ralph69220d · #2 02-09-2006, 09:51 AM

You likely did loosen up some carbon, but I doubt that is causing your present and ongoing problem with rough idle and smoking briefly after startup. It's possible some crud loosened in the rings helping with compression, which might acc't for the overall better performance. If it were me I'd just run it for another month or so and then see how it all looks. It's possible your glow plugs are damaged which would acc't for the rough idle and smoking with a cold start. I'm sure other's will be better able to give some insight than I.

Stevo · #3 02-09-2006, 11:18 AM

Mike

The first thing I would do is check the GPs, have you converted to the new style? It would help even though its proly not very cold where you are

As already suggested, there may be a carbon problem, run it hard up hill (Italian tune up).

redbaronph123 · #4 02-10-2006, 04:20 AM

thanks for the replies.

I tested a theory of mine for the past 2 cold starts. I would pump the pedal three times, then start the car after glowing it for 15 seconds. The car starts up without any problem. It starts and idles fine afterwards. So i'm beginning to wonder if the problem is related to the IP/fuel delivery. I'll be looking at it over the weekend adn probably replace the filters.

redbaronph123 · #5 02-12-2006, 10:14 PM

just an update.

I guess my theory didnt hold water much. Last saturday morning after being parked overnight, i turned my key to glow, then after 15 seconds started it. I started right up, with a little choking, but fired up just as well. Idle fine and off i went. Got back home around lunch time and parked it until the evening.

Started it up in the evening, no pumping of the accelerator, it started right up, and the choking is lessened (as compared to my morning start).

Sunday morning, started it up after 15 seconds, vroom.. hmm. seems like the problem went away. Drove it hard to my destination. killed it, then started it up after being parked for more than 4 hours. It fired up, with a little bit of choking, but nothing drastic. Idled fine, and even drove quite lively.

I wonder, i didnt do anything over the weekend except check the intake. I didnt even replace the fuel filters. i just drove it and drove it like Ralph69220d said.

So what gives??

whunter · #6 02-13-2006, 01:33 PM

Read this thread.

Italian Tune up
Italian Tune up

redbaronph123 · #7 02-13-2006, 09:04 PM

thanks for the thread. Already read it and even posted in it.

Oh well.. everything is back to "normal", didnt change a thing. I just though doing ITUs would make it run better (as it did), however the starting it part was a littl e bit disconcerning.

Anyway.. right "chester" (my car) is happily idling and running amuck at open roads..

thanks a lot for the replies.