xj40 multi point stag system

[josht]

I have a xj40 running a multi point lpg system well just about running. It overfuels on idle and isnt as smooth as it it is on petrol i was told somtime ago that xj40 wernt compataple to the stag multi point setup because of the 2.5 ohm injectors. Just wondering if any solution was ever found for this? Anyone know of a place that would take a look at it for me?

[classicswede]

Not down to injector resistance but method of firing injectors.

I take it you LPG injection times are down at around 2ms on tick over?

[josht]

Yea i think theh were last time i plugged it in il plug it in again tommorow and have alook. Iv herd of other xj40's running the same system just not sure how they did it.

[josht]

I just checked and yes its down at 2 ms. What dose that mean? Thanks in advance

[Tubbs]

Its a full or half group system, and not a sequential injection system.

[classicswede]

Its full group, meaning that the injectors fire twice per cycle. AEB have a great way around this by filtering the second pulse out and then firing the injector for twice as long so your tick over would be opening of 4ms instead of 2x2ms. The LPG injectors can not be acuratly controlled at such low opening times. The other option is to opt for smaller injector nozzles or reduce the gas pressure to gain a good idle but this usualy ends up casuing the system to switch back to petrol under high load as you run out of injector duration.

[josht]

Thanks buddy so i supose my options are to have a play with different nozzles and pressures to make it idle right and then switch to petrol for hard driving or swap to a different setup.

[hardcorepit80]

You can play with nozzles size and pressure, but you need to connect to the controller and set it up properly, otherwise you won't be able to do much...
It's like trying to fix a car without opening a bonnet...

[stype3]

a different option may be to go for faster lpg injectors? such as the magic jet ones?

[josht]

I can connect but it was a year ago since i had a play so il have another try . Faster injectots would shorley help? I dont mind taking it in to let the experts do it but i dont want to waste there time. Any recomendations west mids?

[classicswede]

Tubbs will be the nearest to you

[josht]

Is it the injectors that strugle to fire that fast or the ecu?

[Tubbs]

07931 459385. What system is it ?

[classicswede]

Stag - read the thread title