I'm sure that this has been asked and answered in the past as it's here that I found about this product, but I wanted to mention it again as I just used it to solve a problem I've been having with the '98, one that is a known issue with the 4.0.

The XJ was hard starting after any time idle, not running. It would always start crisply on the second try. No performance or fuel mileage issues. The fuel pressure tester confirmed leakage of fuel line pressure upon shutting off the engine consistently. The cause was one of two possible issues, bad check valve or leaking injectors. The rate and amount of leakage led me to lean toward the check valve being fubared.

I purchased and installed the SUR&R inline replacement check valve yesterday (part #CKV5). It took all of ten minutes, called for use of a tubing cutter and two open end wrenches. The manufacturer suggests installation as close to the fuel tank as possible. The results were immediate and complete. The problem is completely solved. Reattaching the gauge to the fuel rail after installation confirmed that it is now holding fuel pressure again. The big test was after the XJ sat all night, I went out this morning and turned the key. It started crisply on the second crank where it hasn't for a while now. No winding out the starter and the stumbling it did when it started just after regaining sufficient fuel pressure.

I highly recommend this product. The best price including shipping I could find was from tooltopia.com.

 

I'll keep it in mind. Glad it worked out for you.