fuel problems in my cherokee

[AKASHAJEEP]

First off I am new to the whole Jeep thing and to this fourm.
I have recently aquired a 1996 Jeep Cherokee Sport and am now having some problems with the fuel delivery system. I looked through my haynes book and am starting to get really confused about what my system is. (tbi or mpi) I have the 4.0 ho inline 6 cylinder motor with fuel injection and am lead to believe that this would make it the mpi.
maybe while i am here I will ask and see if anyone knows what is going on with her. heres the problem and how far i have gotten into it.

it seems like i am not getting any fuel to the injector rail. i have no pressure on it. i have just replaced the fuel filter, which wasnt that clogged. it had little black specs of something on the input from the gas tank. toinght it did it again. but this time there wasnt any of the black specs in it at all, just nice and clean gas. but now the pump isnt pushing any gas out. maybe this is due to something cloging the pump filter or the pump is completly shot? it was dark and there was a dieseil running in the background, so i couldnt tell if the pump was even going. I tried to blow back through, thinking that maybe if it was a clog that i could dislodge it, but it was really hard to blow through and i got nowhere fast.

If someone has any ideas on what is going o n here i would greatly appreaciate them!

 

[MudderChuck]

I have the 95, so there is likely to be some differences between yours and mine. In the motor compartment on the right fender well, I have a fuse and relay box. My owners manual shows the location of the fuses, relays (and function) in this box. I´d be inclined, to look at the fuel pump relay and/or fuse. Some of the relays are of the same type, but have another function, changing the relays around, can help with trouble shooting (may also just move the problem around).

 

[AKASHAJEEP]

i did take a look at the relay and yes that same box is there on the passenger side. I took it completly apart to see if it was connecting like it should be and found nothing. but didnt try and move them around. I will have to give that a shot in the morning.

 

[AKASHAJEEP]

Problem solved. come to find out it was the connection peices on the fuel pump itself, and the hose from the tank to the filter was rotting. this is where the little black specs were comming from. I am so thankfull that the pump itself wasnt gone. straight from the dealer was a hair under $500. lucked out on that one.
Just thought I would tell you guys what the problem was so for future references you have another route of troubleshooting.

 

[XJNick]

Yes, the 4.0L engine is Multiple point injection (MPI). Throttle Body Injection (TBI) would have two or so injectors at the throttle body :mrgreen:

-Nick :!:

 

[RICHS]

New Guy on the Block

Is there four (4) wires on your connection piece? If so, are two (2) from the relay for voltage & the other two (2) going up to the fuel gauge on the dash?

My fuel pump is not making any noise or is there any gas coming from the outlet to the fuel filter. I took the inlet hose off the in-line fuel filter to verify this.

Is there a fuse that I should be checking besides the relay, that clicks when the key is tun on.

Does it sound like the fuel pump is bad or relay/fuse? Can I take voltage readings @ the four (4) wire connection block? Would it not read 12vdc to prove out that the pump is getting power if the relay/fuse is O.K.