I have a 1990 jeep Cherokee. 4 cyl 2.5L I just rebuilt the engine but I'm having a problem with my fuel regulator or injector. I had a bad fuel pressure regulator diaphragm so I replaced it but I'm still getting too much fuel no matter how I adjust the pressure regulator screw. When I turn the key on The fuel pump turns on and shoots fuel into the manifold but as its cranking it's spraying more fuel than needed.. I took the injector out and cranked it to see how much was coming out but it wasn't the injector.. Could my fuel pump be pumping too much? But isn't that what the regulators for? Why wouldn't the regulator be working if it has a new diaphragm? PLEASE HELP ME IM GOING CRAZY!!!!!

 

read this it explains how tbi works might helphttp://jeep.zerok.ru/index.php?page=126

 

more info here... from what you saying sounds like the injector is staying open to longhttp://www.eriejeeppeople.com/ejpfor...?showtopic=217

 

What's your PSI? If this is the TBI design with the single injector in the center, you need to replace your o-rings and make sure they're seated properly. Otherwise you should have about 14.5 psi, if I remember correctly. May want to check your fuel pump condition as well.