Starting/Idling probs from cold

[zippee]

My Chims not firing up properly from cold at the moment - it catches but splutters a bit before starting and needs a shove of throttle to stop it cutting out immediately which is a bit lumpy. Going along the road as well if I put the clutch down she'll drop to 4-600 rpm and splutter but not stall!
Also she doesn't sound as deep and burbly as normal - shes had the cherry bomb treatment so should be very loud but just isn't!
The stepper was new last October and I thoroughly cleaned it last night along with checking all the leads were on nice and tight but no joy.
Any ideas what else could be causing this? When warm shes fine (though still not all that loud on tickover) but from cold really doesn't sound herself.

[chassis 33]

Could be the coolant temperature sensor giving funny readings making the car think its warm when it isnt. Try shorting the connector to the sensor with a paperclip next time you do a cold start (wrap it all up in insulation tape though) and see if that improves things. Don't leave it in for any longer than is needed for fault finding, cos it will start to overfuel the engine once its warm.

Regards
Iain

[philr]

Mine has been doing this ever since the cam was replaced (upgraded).
I have found that its OK if I let it tick over for 5 mins before going anywhere....which is a bit of a pain. Otherwise its really painful to try to drive and stalls when you breath on the accelerator.

Given by the rich smell of fuel at start up, I think its overfueling on cold start. It was suggested that this is a potential side affect that can happen with the "more aggressive" cam, but may be its something else if yours has just started doing it.

Let us know if you get it sorted.

Phil

[Nuggs]

philr said:

Mine has been doing this ever since the cam was replaced (upgraded).

Did you get the engine remapped after having the cam done?

[HughesieII]

Nuggs said:

philr said:

Mine has been doing this ever since the cam was replaced (upgraded).

Did you get the engine remapped after having the cam done?

Good point - mine has exactly the same Problem after a full re-build and is back with Paul at Austec on Saturday - Mark Adams did a brief re-map on mine as Fuel Pressure was low on tickover, so they turned that up a tad and did a slight remap to get me to Le Mans and back...

[philr]

Yes, Mark Adams did a remap after the new cam was fitted. This improved the low end revs a bit also.

Just got the car back from Austec and they tested out the engine temp sensor. It turns out that this was playing up and bouncing between readings of -2 degrees and 30 degrees, and hence the fueling will have been way off. Not had time to test things for myself yet, but the guys tell me she starts fine now.
Also desperately hoping that this is what has been causing the poor fuel consumption I have been having for some time.

The real bummer is that I replaced the engine temp sensor as part of trying to solve the fuel consumpion problem last year. looks like I managed to swap one dodgy sensor for a new dodgy sensor.

will let you know if this solves all my problems as I know that there are several others out there who's MPG has dropped to about 13 for no apparent reason.

Phil