2.1 SS lumpy tick over, cutting out etc

[Big Bear]

I need some clues of what to work through. My 2.1 SS engine sometimes ticks over ok but other times it is very rough and try to drive it there is no power and it cuts out.
It has been decatted also.

Fuel filter/tank/line are ok as I'm about to replace the tank as it is rotten.

Plugs, leads, dizzy etc are all new.

I'm thinking air flow meter, injection, temp sender? I'm no mechanic so any advice on what to check first would be appreciated.

I gather it will convert to carbs instead of injection. Anybody who has done this and how did you get on?

Thanks everybody.

[jason k]

look at the lambda. you can bypass it to revert to a default map, see if that's any better

[oorwullie]

look at the lambda. you can bypass it to revert to a default map, see if that's any better

he said it's been decatted...............

@the OP, if yer tanks rotten replace it first then check all the filters, pump ,injectors and definately the fuel pressure regulator.

apart from that there's not much to go wrong.

in my humble european experience.

[jason k]

The lambda still goes in the exhaust even if its decatted hence a dicky lambda can cause these issues.

[Aidan]

check idle stabiliser, valve, switch and circuit

[Big Bear]

Thanks for the suggestions everybody! I'll give it all a go.