Subaru playing up when cold

Morning peeps,
My ej20 has been in my van and running perfectly since February in that time I have done over six thousand miles without any issues (it's my daily)
In the last week it has developed a problem in the morning ( not sure but think it's something to do with the cold?) It doesn't happen straight away it happens. After about three minutes of driving .
It loses power and starts to jump around like a kangaroo and feels like a 1600 on 2 cylinders
That will last a couple of miles before getting better?
I have put a scanner on it and the faults are lamber sensor 2 (which is not connected) and idle air control system fail safe? The live dater was perfect at the time of looking so Cleared the codes and sweet until this morning it done it again
Any ideas would be greatly appreciated.
Cheers Steve.

 

@pkrboo may be able to help

 

What are the fault code numbers?

Idle air control valves can get gummed up, might be sortable with a clean, also check for a hose split/loose jubilee on the inlet to the throttle body.

 

Already cleaned idle control valve and checked for inlet leaks ( nothing found)
Disconnected air assist valve no change there ether?
Confusing to say the least?
Many thanks

 

Do you have the smooth rocker covers or the ribbed ones - it gives an idea of the age of the engine.

Later ones can have crank sensor issues which give similar issues as you describe.

If you've only had the engine in since Feb - is this the first cold snap you've experienced?

 

Yeah 1st proper cold I have the smooth rockers the engine ia a 2002 and

 

Is that the late one ?

 

What's the fuel pump set-up on on those conversions? Was it a new pump or a donor? I had similar running issues on an FI T2 - it was a failing fuel pump. Only got the bottom of it when it finally failed all together.

 

If you cycle the ignition does it still play up?

 

New high pressure fuel pump

 

Starts 1st time and ticks over fine? Just when I get a bit down the road it starts titting up then when it's up to temp it's ok again?

 

Yes, my T2 did that, start ok on the initial pump of fuel, then start to faulter within a mile or so, or when going around roundabouts or up hills, when gravity kicked-in and offset the failing pressure/flow of the fuel pump. Then one day it wouldn't start at all, and noticed that it wasn't primming. Changed the pump and that was it.

Edit: just saw your post re new pump.

 

When the engine was fitted

 

It’s a later one.

Who did the install?

A lot of them run with no cats as you don’t need them on easier vehicles and there isn’t a lot of room.

Im wondering if the change of ambient temp means the engine is relying more on the 2nd lambda sensor…..if it’s not been deleted in the software.

 

sorry about them replies I'm just getting used to this.
I did the install myself im running with no cat and the pre cat sensor wire is just hanging there the 2nd is plumed into the exhaust the wiring loom was done by nick tune?

 

So the pre cat lambda is disconnected entirely - the second one is into a loom from Nick Tune?

So the 2nd sensor is effectively non existent, but the plug runs into Nick's wiring loom?

Or is the 2nd sensor plumbed into the exhaust, but plugged into Nick's loom? If so, where does Nick's loom go?

 

It's the second lamba that is not connected and the pre cat is the one I'm using which is in the exhaust