OK got my 99 XJR home and started diag put some more gas in it to make sure it was not empty and primed it to listen for the pump I could hear it and after priming for a bit it would start a lil not well but it started at least. I then decided to pull each relay and install new ones but before I did that I took a piece of wire and jumped the teminals to check for pump operation the one nearest the corner sounded loud and strong, the one in the middle section sounded pretty weak but both made noise at least. So next test was to install the wire and make the pump run all the time. I tried this on the one in the corner 1st and the car started right up idling pretty decent but still not proper. I tried the method doing it to the one in the middle and didnt respond as well. Honestly dont know what that means. But I did try and test fuel pressure but unless the pump was priming or pumping nothing came out the shraider weird. So thts where Im at any ideas would be awesome thanks guys. Still only code is the same one that it had when it was running great with the reduced performance which was 1797 cant look into that until I can at least get it running again

 

Well, it sounds like you may have a dead pump waht do you mean no pressure at the schraeder? I would start there. No pressure in the pipe, or bad valve???? Get a fuel pressure test guage and hook it up and crank the car.

 

I have a fuel gauge and will hook it up but from the looks of things I would say almost zero unless the pump is running cus I wanted to see if any pressure was in the rail with car off and nada pressed valve and nothing came out. But I help it open and had my woman turn the key to on and I got a small drizzle of fuel out not much though

 

Ok checked pressure with the key on it was zero, tried to take out the #1 relay so that it would run on the #2 and it would start but not very well stumbled and sputtered. So I put the #1 back in and then hardwired my #2 to run at the same time as well and started up pretty easy and ran ok but still kinda stumbled and sputtered kinda had to pump the pedal to get it to rev and when it did it was slow but could get it to redline.

 

AND THE PRESSURE WAS ?????? If it was still zero as it cranked, then as they say "There's your sign!"

 

you may have a leaking line in the tank. if 1 of the 2 came off the car wont start at all. youre infor some fun work now pulling the tank. if you do replace both pumps and walbro pumps are direct replacements and very good pumps also only about $100 ea

 

Awwwwww Im a tech just new to the jags usually a chev, audi, ford, guy so learning as I go with this jag I dont like the whole mystery problems LOL but I was looking at the tank doesnt look to bad at all. But think I will take it out tomorrow and see what it looks like inside. I will probably use the autozone ones as they are avaliable an good priced. I have a guy that has a good tank out of a 2001 with only 8k on it before the car got totaled he said I could have the pumps hummmm. Also looking on car part .com and looks like the xj8 pumps are the same but they only came with 1 instead of 2 and they are relatively cheap.

 

Also like I said it barely runs if I hardwire the 2nd pump and it will hold zero pressure almost like the pressure reg has disappeared which would make sense if a line is leaking or disconnected. Like I said I can cycle the pump several times and then press the shraider valve and nothing will come out if I hold it open and have someone turn the key on it gives a small stream with almost no pressure it should shot out hard held open. It should have some in it if its been cycled and I press it too starting to think I have a pump prob LOL

 

and you need a xjr tank because they have pump holders and plumbing for each pump. why not just pull the tank then and replace the pumps and lines......theyre just fuel injection hose. the car will run fine on either pump. I have jumped the relay many times on r's to drive them in the shop when the main fails and the cars are towed in. You can drive the car and never know your on 1 pump....till about 3000rpm thats when the 2nd kicks in

 

well then cant hurt just to open her up and see whats going on inside cus it wont run on either pump and barely runs when I have the 2nd pump hardwired

 

well after some careful thought it didnt make sense that I could hear both pumps running great but almost zero pressure so removed pump had it out in about an hour first time was pretty easy. Opened it up and just as I was hoping the hoses were spongy and the main hose that went to the fuel line after the t fitting was split went and got the best goodyear double braided and internal sleeved 5/16 fuel injection hose (pricey stuff but it should last alot longer than reg stuff) and replaced all hoses. reinstalled tank primed it for a sec and BAM started up flawlessly wooooohoooooo thanks guys for all the help