250 Cold start problem

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by JamesRS250, Feb 27, 2018.

  1. Charlie Howard

    Charlie Howard RSM Club Member

    Did you ever regap your plugs? The thing that solved mine was cleaning the MAF sensors, one was really grubby on the inside. I've got other cold start issues but I think it's just the car.
  2. Na never gapped the plugs, car has been fine for ages now.
  3. Charlie Howard

    Charlie Howard RSM Club Member

    This has come back for me, only does it in the summer. Replaced the temp and map sensors but did it twice this morning and I have to give it some throttle to stop it stalling
  4. Mines exactly the same! Swapped out the iat sensor and it started perfectly for a week or so then stumbled again this morning but didn’t stall! Gapped plugs to .6 and v power in it as it seemed to start when I only half filled on momentum (which I’ve run it on for ages) so thought it could be a bad batch of fuel but obviously not
  5. Charlie Howard

    Charlie Howard RSM Club Member

    Only occasionally though, done it 3 times this year but only since the warm weather.
  6. Same with me so a very weird set of circumstances! Mines off to KTEC on Thursday to get the timing checked anyway so I’ve given them the heads up to check the fuel pump and rail pressures at the same time! It starts fine, idles for about two seconds at about 1200rpm then dives to about 500rpm, then if it doesn’t stall its back up to 1200 til the choke closes it down to normal idle! Yet if I turn it off then start it again, absolutely no drama at all, everything is fine!
  7. Charlie Howard

    Charlie Howard RSM Club Member

    Same with me, let me know if they find anything
  8. Charlie Howard

    Charlie Howard RSM Club Member

    Any news?
  9. Ah sorry responded on a Facebook issue someone was having and forgot to post here! KTEC checked the timing, injectors, fuel pressure and all checked out fine with no issues. They mentioned perhaps a lazy lambda sensor not registering exhaust temps quick enough but with no codes difficult for them to say!
  10. Charlie Howard

    Charlie Howard RSM Club Member

    I wouldn't think the exhaust temperature would change at all within a second of starting the car would it?
  11. Interesting thread. Glad I found it. My 250 is having the same issues and has only started doing it in the hot weather. Mine seems to do it after I’ve driven for a while then stopped for petrol etc. Had done it twice in two days (both very hot days). I will look and clean the sensors.
  12. Mine Mk2 its the same, with 100 octane fuel is better, now i think to change the tdc sensor.
  13. So, some updates? I have the same issues at cold start. Can clip diagnostics indicate misfire in 2 cylinder.
  14. Charlie Howard

    Charlie Howard RSM Club Member

    I'd get a compression test done on that, trouble with hot starts is a symptom of low compression

    Mine hasn't done this in a year now, but even when it did there was no misfires logged
  15. I mean misfire at 2 cylinder with no error at ECU. We just open the parameters in the block and look at the misfires in the 1-2-3-4 cylinder, there is always some amount there, if the number of misfires exceeds the specified one, then the block remembers the error.

    Attached Files:

  16. Just found this thread. My 2010 megane rs250 did the stall upon cold start a few times since i bought the car(a month ago). Luckily, this stalling issue doesn't happen anymore. But my car still has rough idle/light misfire at idle. It's weird that it only coughs or misfires at idle. I've changed the spark plugs and it didn't fix the rough idle. Just ordered the thermostat since it's failing as well. Also keep in mind that the car is tuned(stage 1 remap + pop & crackle). Anyone solved this rough idle issue?
  17. Charlie Howard

    Charlie Howard RSM Club Member

    Idle cough is very common on these, nothing to worry about
  18. This is my cold start.

    Can someone post a video with his cold start.
  19. I can post video, with my cold start and can clip obd scaner.

  20. I figured out a lot while looking for a problem. It remains to change the fuel pump. There is a suspicion of a cylinder head and intake valves. That is, a loose fit of the intake valve on a cold one, possibly due to deposits. I want to try cleaning the combustion chamber with the intake valves open.
  21. Yes please
  22. Hi,
    Do you have any news
  23. hi, i have same problem.
    when weather is very hot and leave car under sun, when start, the engine coughs and i need to rev for 10-20 sec or it shut down, after it's all ok.

    also there is some misfire in idle..
    the previous owner has changed coils, spark (are fr7ki332s, can do problem?), camblet, injector , i've changed TDC sensor, clean throttle body , camshaft sensor (
    obstructed), maf , next week i replace coolant temp sensor and fuel filter; tested dephaser solenoid and work.
    one time i find p0130 error(o2 sensor circui bank 1 sensor 1, pending), delete and never came again

    last question, when i rev over 5k, i smell like there is a leak in exhaust, maybe flexible, can be it the problem of misfire?
  24. Здравейте, някой реши ли проблема със студен старт?

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