Hey guys, to start its a 96 xj . 4.0 i just replaced my fuel pump and fuel filter now itll start just fine then if i either idle for a minute or two or try to press the gas itll sputter drop to like 2-300 rpms and then itll stall out and die. I have fuel at the rail at all times. Is this my tps ?
Thanks in advance!

 

It would be a it of a coincedence to fail right at this point, so my first action after something has changed for worse after an intervention, is to check the work done. Pump working, good fuel pressures?
But assuming that your fuelpump is working as it should: TPS, yes could be. Test it, preferable with an analogue DV meter, which gives you a good visual 'gauge' sweep.

 

What kind of readings am i looking for?

 

I think its around 0.5V closed to 4.something Volt at WOT. But somebody might chime in here. You can also do a search on how to test your TPS, there will be links to several threads.

 

 

Still no start

 

You're looking for 32 - 39 psi of fuel pressure at the rail. It's possible you could have a defective fuel pump. Also is the filter going in the correct direction? Sounds silly, but the way certain filters are designed will allow fuel to flow the wrong way at higher RPMs but not so much at lower. How is TPS, MAP,and ECT? These 3 can fail around this time of the year. Also, check the fuel pump ballast if equipped.

 

im throwing in a new tps today . keeping my fingers crossed it just like dies after a few seconds totally confusing

 

So the fuel pressure is within spec?

 

What brand of fuel pump did you install? Hopefully not an Airtek. They are crap and can be bad out of the box. Your best bet would be a Bosch then a Carter. You should verify you fuel pressure at the fuel rail with amechanical pressure gauge. The pressure should be 39psi + or - 5psi.

 

i installed a carter pump and motorcraft filter.

 

Carter is a good brand. But, I would still run a fuel pressure test to make sure that you didn't get a bad pump. You can still get bad parts even with a good brand.

 

So checked the rail and had no pressure and no fuel yesterday. Smacked the gas tank while cranking and now its firing and driving fine, ive started it a few times with no issue now. Any one know why? o.O

 

Sounds like your new fuel pump is sticking or you have a loose connection.

 

If you ever have any more fuel pump problems then consider switching to a Bosch. I'm convinced they are the best,( just by my own experiences ).