I own an 2012 RCZ THP-156 with 77,600km. About a year ago started getting the P0087 code and missfires. Changed plugs and coils, same problem. Was told it was the HPFP. Ordered Chinese refurbished got a dud (27mm). Took my own pump apart (as per You-tube videos) cleaned refilled with hydraulic fluid assembled (while submerged) got 15mm on the membrane (27mm is a fail). So far have driven 5500km without any problems.
PS. some bloggers who do these pumps have told me that 15mm creates too much pressure and that the pump will fail within 3000km (so far Ive done 5500 already) They recommend just refilling the pump with the help of a syringe and that the ideal measurement is 21-23mm. Refilled pumps like this last usually between 9-15,000km and can be refilled up to 4 times until you have to change the internal parts (available in China on Ali-Baba , A$250 and I don't know if they are any good). Cost A$20 submerged method you use about 2.5 litres of which 150ml goes in the pump and the rest contaminated OR Syringe method A$2.
PS. some bloggers who do these pumps have told me that 15mm creates too much pressure and that the pump will fail within 3000km (so far Ive done 5500 already) They recommend just refilling the pump with the help of a syringe and that the ideal measurement is 21-23mm. Refilled pumps like this last usually between 9-15,000km and can be refilled up to 4 times until you have to change the internal parts (available in China on Ali-Baba , A$250 and I don't know if they are any good). Cost A$20 submerged method you use about 2.5 litres of which 150ml goes in the pump and the rest contaminated OR Syringe method A$2.