hunting and too rich on cold start up

[zen]

hi..

she has beeen fine for ages.but just started hunting
and far too rich on cold start up..
cant find any vac leaks..she is perfect when hot start.no fault codes..

she fires up fine.but hunts between 500rpm and 1000rpm.a/f meter says
10:1 or less!!.will die if left with no throttle.with light throttle still hunts...

iacv??

car is 1995 gen 2.supercharged.

no other faults..

thanks

 

[ruishy1]

02 sensors maybe

 

[Nick M]

Runs bad when cold and fine when at operating temps? Have you checked for any DTC's? The AF when cold is supposed to be rich anyway, but check for those codes. Your engine might just be getting worn.

 

[zen]

as stated no codes..engine aint worn..

not lamdas..was fine one day not then next..tis only when cold start say in mornging.
but was fine today?now if it plays up it has difficulty in stabilising idle for first minute.its while
a/f ratio is below 10:1..ie 8:1..once it pulls it leaner its fine...

 

[Bushwhacker]

EFI coolant temp sensor?

 

[zen]

Possibly later.but it drops down to idle when hot...

 

[cribbj]

Are you running an injected LPG setup or a fumigation (carb type) setup?

Have you had any intake backfires - that could cause your MAF to be off?

Dumb question, but how do you know it's running rich? Have you looked at the plugs or are you getting black smoke, etc.?

 

[stevieg]

Coolant temp sensor going bad?

 

[zen]

lol..alll fine..ecu rest..job done..

 

[zen]

UPDATE...
went tits up again....

turns out trim was out too much on lpg sytem(too weak) was tuned for economy,recalidrated lpg now petrol side is not trying to pull rich..sorted..ecu retrimmed itself .