89 jeep cherokee no fuel

hello everyone new to jeeps but not to problems! i got this truck for trade,was told it was running but quit and wont start. 89 jeep cherokee 4.0,4wd,auto. Not getting fuel to rail,new fuel pump,had it out of tank and when put ignition to on feel pump running,installed in tank with hose going to gas can not pumping fuel,unplugged fuel pump there is 6.5 volts from one of three wires from connector and 8.5 volts from other,with and without ballast hotwired, i know there should be 12volts from the one,put in new cps but checked both new and old and they are both in spec,ads and fuel relay both functioning,the ground wire had broke off the fuel pump so i drilled a hole in it and made a new ground,dont know what else to do or look for!? any advice would be greatly appreciated! thank u in advance!

oh by the way the truck will start when you spray it with starting fluid

Measure the battery voltage between the terminals--how many volts there?

battery was at 12.22 after all the cranking was done by it this weekend,could a low battery or junk battery terminal be a problem? the positive wire looks pretty chewed up,was going to replace it.

Hello finally got back out there and this is what i have. 12.98 volts at battery terminals clean and tight 0.00 resistance form ground to block behind dipstick. with key on power going into resistor ballast 8.98 volts,after relay stops clicking .89 volts going in and .07v coming out. With ballast jumped with key on 9.02v after relay stops clicking .09 volts in .07 volts out. but either way i thought i should be getting 12 volts coming from wire to ballast. i have read on here something about c101 connector getting corroded,i believe mine is behind, under brake booster. does this wire going to ballast go to fuse box or ecu? is there a way to check volts on interior side for 12 volts? any of your guys expertise on were to go look at would be appreciated! i dont want to do this to my jeep :explosion Thanks in advance!

ok have my hanes manual out and looked at computer,the wire going to ballast is orange/black,only orange/black wire coming out of computer ,with key on volt meter is saying 12.98 volts coming out of computer so i am loseing 4volts from computer to ballast,does that wire go to fuse box or directly out through fire wall to ballast? thanks

the wire from the ECU doesn't run to the ballast at all-- the ECU controls the fuel pump relay (along with other relays like the B+ latch relay) and the relays carry the current to the resistor and the pump.

Shorty said:

the wire from the ECU doesn't run to the ballast at all-- the ECU controls the fuel pump relay (along with other relays like the B+ latch relay) and the relays carry the current to the resistor and the pump.

Click to expand...

Correct.

The ECU provides the energizing GROUND to the B Latch and fuel pump relays, the ignition switch provides the positive side of the energizing circuit, and when energized it is battery power that goes to and through the ballast resistor.

Burn that Haynes manual. You want something to cover your butt, buy Haynes. You want to work on a vehicle, buy a FSM.

chiropeeps said:

but either way i thought i should be getting 12 volts coming from wire to ballast.

Click to expand...

you'll only see 12V when the vehicle is running-- the resistor is bypassed during "start" mode.

If you are only getting 8.5V to the pump, it sounds like you are losing power either at the FP relay, B+ latch relay, or the battery post on the starter relay (silver box located just aft. the battery)-- I'd start at the relay (since it's the power feed for all of the circuits) but any/all of them can give you your headaches.

thanks guys for chiming in , i ordered fsm this morning, after work i will bust out the volt meter and start checking the power to those relays and cleaning them up some more,thanks for heading me in the right direction,ill post what i find, Thank you!

chiropeeps said:

thanks guys for chiming in , i ordered fsm this morning, after work i will bust out the volt meter and start checking the power to those relays and cleaning them up some more,thanks for heading me in the right direction,ill post what i find, Thank you!

Click to expand...

Your 89 won't have the C101 connector, it was located above the brake booster:

Your right i dont have that connector. But after reading many posts on here,did some more investigating. Joe peters keeps saying about the grounds,so started cleaning, looking, my buddy picked me up a 4 gauge wire for that metal strap ,but its four feet long so have to take that back and get a shorter one but i did find two grounds by dipstick that were never installed after new wire to block was installed by previous owner. so i am headed in the right direction?! i hope!

ok today results== b latch relay i think because its 1st coming from battery, but right colored wires 2 pinks,red,black

key off
30---12.8 volts key on --- 12.6v
86 ---- .2 v --- 11.8v
87 ---- .2v ---- 11.8v
85 ----.0v ----- 1.4v

fuel relay 2nd back or/black,org, yellow,red
key off key on
30---- 12.8 12.68
86 ---- .1 12.6
87 .0 .3
85 .0 .8

pump still not coming on,didnt have a helper turn the key if it matters, after installing the grounds,that were disconnected the relay only makes a small click as before,it would go click,click,click!

but a small jumper wire between ballast,didnt have time to solder it in,but it seemed like the wire was getting hot?

volt meter on battery 12.68, while cranking 10.7--11.5. and one other thing i read while cranking my tach does not move.

sorry so long just trying to give you guys as much info as i can. Thanks in advance for any help or where,what to look at next!

today i put in a new 4ga ground from block to fire wall,same results,testing all relays and wires,on the D1 block i have 12.8 volts at 1(green/white wire) 5 (red wire). At D2 block i have 12.8 at 4(yellow) and 12(pink/black). went through all orange/black wires and no power at any of them. And i believe the 02 relay on the wire side i can see the copper of the wire,but it is attached. i will be replacing. Checked at ecu back probed ecu orange/orange black wire,getting .35 volts the same as all the other orange/black wires so??? Ecu possible no good? help anyone? thanks

just wanted to say to all who helped out,it turned out to be a short in the whole fuel pump assembally, swapped out whole thing from parts truck and she fired up!! Another xj saved and on the road. Thank you all