Jag V8 RISN Running Lumpy

[xj8user]

Hi just returned to LPG cars after a few years out. Bought an 4.0l S TYPE Jag with Romano RISN conversion. It felt a bit gutless so decided to check/replace Spark plugs. The existing plugs were Platinums and gapped at 1.3mm? checked on web and fitted denso iridiums and gapped to 0.8mm.
It seemed fine for first day but am finding that it is really lumpy around 1500-2000rpm with possible misfires havent had a chance to read DTC yet but can a change of plugs necessitate a recalibration? No MIL or Restricted performance.

I dont have software to check the Romano ECU Can I use Zavoli or other AEB software?

[Tubbs]

No it has to be romano software im afraid.

[Gilbertd]

I'd have gone for NGK Iridiums (or even copper) to be perfectly honest. Denso seem to work well in some cars and very badly in others.

[xj8user]

Hi normally I would nave used NGK but I had the Denso's lying around and have always found them to be equal to NGK and beetter than the rest?
I have copy of software now so will have a look at how its running over next few days and then decide next step. I got the car for the price of a cheap 4cyl conversion so dont want to be spending too much on it until i reckon its gonna last!!

Thanks will be back on in a few days if I find any issues.