I thought for sure I knew of a write-up with more instructions and pictures, but all I could find for now is this one. At least you can still see the o-ring that is the culprit.

 

Good info on the o-ring. Reading through the fsm I find it says that the check valve is on the outlet of the fuel pump and holds the fuel in the line. The rest of the assembly doesn't affect the hard starts, so if anything I might just replace the fuel pump and not the rest of the assembly. However the o-ring idea looks promising. On my xj I plan to replace that o-ring. I know that my fuel pump is working fine outputting 47psi, so I would rather not replace it, but will if the o-ring doesn't work and the check valve is the real problem.

 

sorry to ressurect this thread lol but whats the difference between the pump 4doors showed me earlier,


and this one,


and both these assemblies replace the check valve, regulator and filter?

 

I bought the second one already. It is like $100 cheaper than napa but takes like 6 weeks to ship though I think it depends on your year. I don't trust amazon, so I would go onto rockauto.com look up your year xj and the bosch fuel pump part number. Then use that when deciding which one to order off amazon.