Cold Idle Blues

[Okibi]

I'm only really an observer to this thread but hats off to Rotary for being so helpful and taking time to explain everything.

[Rotary]

Interesting little problem this one, hard to problem solve Injection issues when not its not in front of you, but Mark’s described it all very clearly so makes it easier to assist, and hopefully made for an informative read
Be good to see what it ends up being.

Mark how’s the Cat law work in SA, did it come in later than 1986 or something else, got me interested now.

[madboy]

This will probably be way off the mark, who knows. I recenly changed the 3 hoses that carry water around the inlet and tb which i think are used by to determine cold start temps and idle...sorry i am not very conversant with EFI yet so if i am wrong about what they do, sorry,

But, before i changed those hoses my car would start and hover at only 900-950 rpm on cold starts, turn the air con and lights on and it would bearly tick over, I have only had it since early December so i don't know how it would have handled mid winter but after i changed those hoses it now idles at about 1200-1300 rpm, still a bit low but much better than just above warm idle.

I don't know what changing those hoses did but they were very old and all the hose barbs were rough with corrosion and the ends crusted with oxidization, maybe i cleared a blockage or removed an air bubble. What condition are yours in?

MB

[whoa_dang_96]

This may be a silly question but have you checked..
- the TPS to ensure it is adjusted correctly as the ECU may not know it should be in idle mode if the 2 relevent contacts in the TPS are not made when the throttel is closed ????
- the AFM - I have encountered issues before where the contacts in the AFM that enable the fuel pump to pump can get a whisker between them and cause issues, similary I have had an AFM where the first or second pad on the sweeper board has burnt out causing issues as this is where the sweeper arm in the AFM sits during idle - you could drop of your filter box and try pushing the AFM vane with your finger to see what happens

[93_Clubman]

* SOLVED* Pinching off the fuel pressure regulator helped, but it was just masking the problem, which was a small air leak in the breather pipe off the rocker cover which id managed to miss! This caused a lean run which affected the engine more when cold. Its amazing how suceptible the engine is to even the slightest leak in the induction tubing. Im going to have to change out the whole inlet duct from the air filter as its currently sealed with electrical tape around the joints!

Who'd have thought such a simple answer to a seemingly major problem!

As you're asking

only other thing that comes to mind is that when cold you have an air leak which seals when warmed-up.

Good to hear you finally got it sorted - I haven't read the engine section of the forum for a while & wondered how you went.