Flat spot/occasional miss on acceleration

[roperman]

Just a quick one.

Got an MG ZR running on an SGIS Junior kit. Car cruises fine, and the fuel trims are mostly within about +/-5%.

Only problem is on accelerating from low revs it feels flat, and occasionally misfires. It is definately slower on acceleration than petrol in the lower revs. Higher revs it is hard to tell as it is pretty quick anyway.

I put 2.5mm injectors in because there was a chart that came with the kit that suggested that this would be right. However, in the software when I autocalibrate it seems to suggest that they are slightly too big. I turned my gas pressure right down as well, and it was still saying that.

Would going for 2.0mm injectors (and putting the pressure back up) help on this or will it make no difference?

Is it more to do with my setting up? The map thats currently on it has the gas injector times around 100-115%, is that a bit low?

I had a play with the enrichment in acceleration but I think if I go any further one way it misfires more, and go the other way and it seems even slower accelerating.

The sensitivity for micro injections seemed a bit of a black art, I ended up at about a quarter of the way across. Any advice on what to look for when setting would be greatly appreciated.

I recently closed the gaps on my plugs down from 1mm to 0.8mm but made no difference.

[rossko]

Be really sure about the ignition. If you've got something like tracked plug boots, ropey leads or coil starting to break down, it will show up more under throttle and will show up more on LPG than petrol.

How does gas pressure behave under stress? What sort of gas injection times do you get under load?

[andy evans autogas]

I wouldn't be surprised if its running out of phase !!!!