On the downside 178.48 (Kijun-Sen) is acting as short term support and any break below will drag the pair further down till 177.82/177.
The pair's short term resistance is around 179.40 and any indicative break above would extend gains till 180.36/181.
Indicators (4 Hour chart)
(50) - Buy
(14) - Sell
Recommendation: Sell GBP/JPY around 178.70, SL 179.51, Targets 177.10.