Hanging revs idle issue 1.4

[leejd]

Hi, I'm currently building a 1.4 puma rally car I'll be using the standard 1.4 sigma lump but I'm struggling to get it running right. It idles at 1500rpm and when dropping from higher revs holds at 2000rpm only noticeable thing is when the clutch is pressed the revs drop straight to 1000rpm but then climb back to 2000rpm currently I have changed the tps and icv every vacuum pipe coming off the throttle body and cleaned the butterfly I've also cleaned the maf I've replaced the clutch position sensor aswell but the problem is still the same I've tried to disconnect the maf and speed sensor but both just make the car stall straight away, any help would be really appreciated

 

[hotrodspike]

Have you still got the power steering sensor on the power steering pipe underneath the radiator? If so, check the cables haven't perished/broken. If they are broken the lack of signal from the sensor stops the ECU letting the engine revs drop and they'll hang.

 

[leejd]

Hi thanks for the reply yeah it's still connected it's one of the first things I tried to solve the problem but it's completely fine

 

[silverpuma]

After owning my Puma for 18 months the revs started hanging a couple of days ago sometimes as high as 4000 rpm which is not good at traffic lights/roundabouts, I searched the forum for a cure and tried the free fix first which has been mentioned on the forums. I disconnected my battery for 30 minutes to reset the ecu added 10 minutes to make sure and my Puma is running normally again thanks to the member who posted this solution. :grin:

 

[trublustu]

I`ve had this issue since a recent rebuild.
From startup the car ticked over perfectly but if i revved the engine it would take aged to settle.
I swapped a few parts and checked for leaks with easystart.
In the end I found the throttle position sensor was to blame.
As you`ve done that I`d look at the Idle control valve..

 

[748]

I recently fitted a refurbed throttle body on my FRP from a standard 1.7, complete with TPS.
Same symptoms, revs hanging between gear changes.
I put the original TPS back on and it was back to normal.
I think it's something to do with calibration of the TPS, if you reset the ECU (which I didn't bother with) it will 'relearn' the positions of the TPS.
Paul