hello everyone, im new here, I own a 1999 jaguar XJR 4.0 supercharged. recently my fuel pumps failed and after changing them and fuel filter for some reason the car starts fine but as soon as I try and drive it its as if the car is in a limp mode and not getting enough fuel and stutters as if its about to stall. this only happens if i put my foot down and accelerate past 3k revs. seems as if the 2nd pump is not kicking in. I have checked fuses and relays, i have tried bridging the relays and running the car with both of the pumps constantly running but the same thing happens. anyone have any suggestions or encountered this problem before? please help

thank you!

 

Try following these instructions as it worked for me when I had similar problems with my Super V8

 

if you replaced the strainers and didn’t run the filter backwards, check the in tank hose and make sure you didn’t poke a couple holes in it.

the last thing is to do a voltage drop on the noise supressor boxes off the link leads. these absolutely kicked my *** before on a car that was ok when cold and was terrible once it warmed up

 

Sounds like a backwards fuel filter: Arrow should point to line going to the engine, NOT back towards the gas tank.

I have told this story before: once upon a time -- 1967 -- we tuned a buddy's 59 Chevy six, new plugs, points, air filter, rejetted the carb for Rocky Mountain driving and took off for Loveland Pass (13000ft or so); car worked well in Denver traffic, but once on the open road stuttered and stalled.

While I did the ignition, he had installed the in-line fuel filter -- backwards. Turned it around and off we went.

 

i have just switched the filter around just in case it was backwards but its still the same problem

 

Did you remove the fuel lines from the bottom of the tank?
Did you cut a hole in the parcel shelf?

 

Sounds like someone yanked the tank back to replace the pumps in ‘just five minutes’ and squished the fuel lines underneath.

 

is it producing any check engine codes?

 

Are you getting an engine light on when it happens? My XJR did similar behaviour and it turned out the wrong MAF sensor had been fitted.