mardi 2 septembre 2014

IAT sensor, warm start potentially influenced by heat soak etc.

My nemesis, the warm engine starting issues are, currently, quite docile but, still there, since a long list of replaced parts (I wrote a lot on other threads about them :facepalm: ).



It is my first car with such problems and I will not stop searching the cause and fix this, as it just annoys me to have an engine so "lazy" to start, the warmer it is. :banghead:



Recently, I was looking at - "excuse me, Your Honour!" - I had a vision of having a genuine INPA software and specific hardware - and virtually noticed the high temperature recorded by the IAT (intake air temperature) sensor, after few hours the engine has been shut down, due to its heat soak. For example, last evening, outside temp was about 77 deg F and the engine bay temp, registered both by coolant temp sensor and the IAT one, was about 150 deg F.



So, I can imagine what the IAT sensor is registering, before a warm engine start-up, on hot summer daytime, especially if you keep your car in direct sunlight. The 200+ deg F coolant heat soak + over 110 deg F outdoor temp etc.



I am wondering if this high temp, registered by the IAT sensor, could cause all these warm/hot engine starting issues, without triggering any error codes, as the IAT sensor itself is measuring correctly. :hmm:



I am confused as, when these warm start issues occur, you can smell fuel odour - more like a rich mixture, instead of lean one, which should be expected, if the IAT sensor registers a high temperature, am I right? That's why I am still not excluding some fuel pressure issues, leaking injector etc.



I have also noticed some older M3 thread, about the IAT sensor relocation (which, currently, seems to be installed on the intake manifold, so directly exposed to heat soak and harsh temperatures).

Anyone else recently tried this? Like relocating the IAT in the air intake box, for example - although, I doubt there will be any less impact of the engine's heat soak...:tsk: Still, I felt the need to ask about it, to try anything related to the IAT, as well.



P.S: Why most threads about the coolant temperature sensor refer only to the one next to the radiator? I have replaced that, as well, long time ago but, I've noticed many talking just about that one - when, there is one, more rellevant to the DME, on the cylinder head, quite rarely mentioned? :hmm:




Aucun commentaire:

Enregistrer un commentaire