herbiemercman Posted June 12, 2018 Share Posted June 12, 2018 Hi Guys, Recently my engine is running really rough on cold starts, it seems to be over fuelling and you can smell petrol, when i rev it up for a few seconds it runs perfectly and drives well. I am now at 2 years and 2,500 miles from my single turbo conversion, could the problem be caused by some sort of temperature sensor, i ask this as something must be telling the ECU to dump too much fuel in ? Any help will be appreciated. Herbie. Quote Link to comment Share on other sites More sharing options...
Scooter Posted June 12, 2018 Share Posted June 12, 2018 Coolant temperature sensor can do this I believe? are you still on the stock ecu with a piggyback? Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted June 12, 2018 Share Posted June 12, 2018 When was the last time you refreshed your spark plugs? Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted June 12, 2018 Share Posted June 12, 2018 So you are single turbo? Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted June 12, 2018 Author Share Posted June 12, 2018 Hi Guys, Thankyou for your quick reponse, Scooter, yes it could be the temp sensor,this is the first thing i will check out, yes i have the "Emange" piggy back on the stock ECU. Mike2jz the spark plugs were changed at the single turbo conversion for a compatible type. Swampy yes i am single turbo. When the engine warms up the tick over is perfect and so is the performance. Does anyone have a schematic diagram of the cold start fuelling system? Herbie. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted June 12, 2018 Share Posted June 12, 2018 Can you not pull the datalogs? That will give you a hint at whats wrong Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted June 13, 2018 Author Share Posted June 13, 2018 Hi Swampy, I have no software for diagnostics, i have access to the Mercedes "Star" at my local garage, may be he can take a look. Do you know if the Club has any Mk4 software? Herbie. Quote Link to comment Share on other sites More sharing options...
herbiemercman Posted June 13, 2018 Author Share Posted June 13, 2018 Hi Guys, Problem solved i thought i would examine closely all the vac pipes and i found one split at the end where it joined the plastic "T" piece, i cut the end off and reconnected it, i am not sure were it terminates apart from seeing one end connected to the air intake manifold. see pici. Engine now starts as it used to fast tick over smooth, then in 5 mins cold start goes off and perfect tick over. It is great when some things are quick and easy, i thought i was about to start a diagnostics walk in the fog, so i am reet chuffed. Thank you all for helping. Herbie. VAC.PIPE.jpg (532.4 KB) Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted June 13, 2018 Share Posted June 13, 2018 Once work! Easy fix ftw Quote Link to comment Share on other sites More sharing options...
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