Outer Limits 4x4 Board

I have 90 GQ with a 305 Chev. The motor is standard except for a light cam on it. It runs of pure LPG. I currently live in Penrith, Sydney. On the weekend I went up the blue mountains to lithgow and oberon. While up there the car felt slugish and it miss fired and back fired in 4th and 5th gear on the smallest inclines where in penrith it would just power up not needing to go back to 4th or 3rd.

I will know more next week when I start driving to TAFE everyday but it did feel better when I was back home. What is the couse of this?

Is it the altitude. Lithgow is about 1100 metres above sea level. If so how can this be fixed? Thanks

my parents 60 series used to play up all the time when we were up the mountains.

solution.

don't go up the mountains.

tooo leann