live data showing 250 RPM with engine off

[da rok]

howsit gents, noticing a problem when starting the car while its still warm, at least 70 to 80 deg on the coolant temp, itll start fine then the revs will drop very low after the initial starting blip before it climbs to around 750 again, while reading live data I noticed that with the engine off, its still showing 250 RPM, on other cars I've used the unit on ( cheap bluetooth 327 unit) all the values are as to be expected... just wondering if its one of those french things or could the tdc sensor be on its way out...

anyone had a similar problem?

 

[bloke]

rings a bell, think it's because the butterfly isn't fully closed in it's natural position.

i could be talking crap though!!

 

[j4mes-c]

Mine does this too. Engine off and rpm shows ~250

 

[da rok]

Ill give the tb a clean, j4mes, have you got any idling issues? 250 rpm might just be a french thing... might try plugging a new sensor in and see what it reads

 

[da rok]

Ok changed the tdc sensor... now showing 200 rpm when engine is off, so ill put thst down to just beeing french... checked the cts, all good, gave the tcb a clean, although it wasnt that dirty it made a big diference to the idle and response of the throttle.... will see how it goes when its semi warm

 

[j4mes-c]

Ill give the tb a clean, j4mes, have you got any idling issues? 250 rpm might just be a french thing... might try plugging a new sensor in and see what it reads

Seems slightly unsteady but my TB was all cleaned out and everything checked when I had dephaser and belts done last week.

 

[da rok]

Right a slight update, oddly enough the idle went very low in the same place it did last time, this time the revs showed zero then it slowly built up to normal idle again, didnt stop or actually stall, drove around a bit and gave it the beans, this made it idle high... so on a hunch i unplugged the map sensor and it stalled straight away, there was quite a bit of oil in it so i gave it a clean and all seems well...

Question is, should the engine stall if the sensor is unplugged?

 

[j4mes-c]

Which is map sensor? I caught one of my sensors and the plug came out just after painting my inlet manifold and it cut straight out. Was the one where the ht leads are routed

 

[da rok]

yea map is the one at the top of the manifold, nearest the tb and the inlet temp sensor is injector side...

good to know mines not the only one that stalls when its disconnected :smile: