No fuel in lines or pressure
#16
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
So, it's got to be between the relay/solenoid and where the resistor is.
See if you're getting power to the cavity that #30 pin of the fuel pump relay fits into. Key off. Red wire.
Check the same at the cavity the 86 pin goes into with the key on. Yellow wire.
See if you're getting power to the cavity that #30 pin of the fuel pump relay fits into. Key off. Red wire.
Check the same at the cavity the 86 pin goes into with the key on. Yellow wire.
#17
#18
Thread Starter
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Joined: Apr 2013
Posts: 1,153
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
I appreciate the help and the patience guys...
Well nothing so far... i noticed that the harness that has the four relays is pretty much melted or corroded. So i am kind of desperate now, i cut the wires that would go to the fuel pump relay socket; its a red, orange, yellow, and orange/black wire. I cut the tips, put heat shrink quick-disconnect terminals so i can plug each connector in the relay.... and... nothing
I replaced the fuel filter because i know i have not done it for a while but i know was not going to change anything. The fuel on both sides was still pretty clear so whatever...
As night was getting closer i tried a couple things more:
(1) I have power going from the red and yellow wire which if i am reading the haynes manual is red (always hot) and yellow is when the ignition is on. While the ignition is on i probed with a test light the orange and orange/ black wire, noticed no power going to them but when i touched the connector of the orange wire with the test light i can hear the relay click or make its noise. So that leads me to think maybe that somewhere on the orange wire its hitting a ground or another wire.
(2) the second thing i did which kind of scared me was i used a regular wire, cut the ends to expose the wires, stuck one side into 87 i believe and the other side into 30. Not only did the wire get hot but i saw some sparks at the connectors. Did not hold it there long since i noticed it did not do anything. Hope i did not fry a wire somewhere or damaged something.
(3)So the next thing i did that probably did not have anything to do with the fuel pump is i disconnected the CPS for about 5 min., cleaned it and put it back.... nothing.... now it is starting to get to me, luckily my neighbor saw me trying to figure it out and brought me a beer....
Well nothing so far... i noticed that the harness that has the four relays is pretty much melted or corroded. So i am kind of desperate now, i cut the wires that would go to the fuel pump relay socket; its a red, orange, yellow, and orange/black wire. I cut the tips, put heat shrink quick-disconnect terminals so i can plug each connector in the relay.... and... nothing
I replaced the fuel filter because i know i have not done it for a while but i know was not going to change anything. The fuel on both sides was still pretty clear so whatever...
As night was getting closer i tried a couple things more:
(1) I have power going from the red and yellow wire which if i am reading the haynes manual is red (always hot) and yellow is when the ignition is on. While the ignition is on i probed with a test light the orange and orange/ black wire, noticed no power going to them but when i touched the connector of the orange wire with the test light i can hear the relay click or make its noise. So that leads me to think maybe that somewhere on the orange wire its hitting a ground or another wire.
(2) the second thing i did which kind of scared me was i used a regular wire, cut the ends to expose the wires, stuck one side into 87 i believe and the other side into 30. Not only did the wire get hot but i saw some sparks at the connectors. Did not hold it there long since i noticed it did not do anything. Hope i did not fry a wire somewhere or damaged something.
(3)So the next thing i did that probably did not have anything to do with the fuel pump is i disconnected the CPS for about 5 min., cleaned it and put it back.... nothing.... now it is starting to get to me, luckily my neighbor saw me trying to figure it out and brought me a beer....
#19
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Joined: Apr 2013
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
So whats the next plan you ask?
Well i am thinking 2 things; i either buy a new pump and pray to god it was that to begin with or i was thinking on using a fusible link with a 30 fuse on it to connect 30 and 87 together, hope the fuse does not pop, and trace the orange wire till i have no power or problem. It has to be from the relay to where the ballast resistor wire, that is the easiest spot i checked for power first. And since it dint have power its gotta be somewhere between there.
Well i am thinking 2 things; i either buy a new pump and pray to god it was that to begin with or i was thinking on using a fusible link with a 30 fuse on it to connect 30 and 87 together, hope the fuse does not pop, and trace the orange wire till i have no power or problem. It has to be from the relay to where the ballast resistor wire, that is the easiest spot i checked for power first. And since it dint have power its gotta be somewhere between there.
#22
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Joined: Apr 2013
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
yea that looks familiar, its less than a couple inches away from where the relays are. If i remember correctly i put the test light to the nut where the battery connector is.
I guess i should remove the orange wire? Am i testing if there is power in the relay (that is the starter motor relay right?) or am i testing the orange wire by itself if there is power?
I guess i should remove the orange wire? Am i testing if there is power in the relay (that is the starter motor relay right?) or am i testing the orange wire by itself if there is power?
#23
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CF Veteran
Joined: Apr 2013
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
no fuses are being blown, its a renix model so the only thing controlling the fuel pump is the relay.
Maybe it can be that ground on the starter relay?
Maybe it can be that ground on the starter relay?
#24
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
85 gets grounded by the ECU
With power to 30 and 86, 85 gets grounded by the ECU and 87 gives power to fuel pump and injectors.
#25
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Joined: Apr 2013
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
Yea i did notice that in the haynes manual... the orange/ black wire goes to the ECU. But thats great to hear that i do not have to worry about power going to the ECU. So its the orange wire that is giving me the problem.
I guess if i have time ill check where the power from red to orange is going... as well ill check that starter relay
I guess if i have time ill check where the power from red to orange is going... as well ill check that starter relay
#26
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Joined: Mar 2010
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From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
#27
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Joined: Jul 2011
Posts: 551
Likes: 25
From: West Covina, Ca.
Year: 1988
Model: Cherokee
Engine: 4.0
Note from DJ
Be careful about jumping thinks in your fuel pump relay socket. It sounded like you were think of jumping thinks with a 30Amp fuse link; the later model Jeeps operate there fuel pumps with a 15Amp Fuse. If you use a to high Amp Fuse when checking you are going to melt the Fuse Link that provides power to Pin#30 in the Fuel Pump Relay. I think if it were me I’d make up something with a replaceable 15Amp Fuse and jump between Pin30 and Pin87 of the fuel pump relay. If it blows the 15Amp Fuse I would crawl under my Jeep and unplug the Fuel Pump Connector and try the jumping idea again to see if it blows again.
Here is a photo of fuel pump relay socket except there is no connector in slot 87A.
Be careful about jumping thinks in your fuel pump relay socket. It sounded like you were think of jumping thinks with a 30Amp fuse link; the later model Jeeps operate there fuel pumps with a 15Amp Fuse. If you use a to high Amp Fuse when checking you are going to melt the Fuse Link that provides power to Pin#30 in the Fuel Pump Relay. I think if it were me I’d make up something with a replaceable 15Amp Fuse and jump between Pin30 and Pin87 of the fuel pump relay. If it blows the 15Amp Fuse I would crawl under my Jeep and unplug the Fuel Pump Connector and try the jumping idea again to see if it blows again.
Here is a photo of fuel pump relay socket except there is no connector in slot 87A.
Last edited by djgrayxj; 02-26-2017 at 08:16 PM.
#28
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Joined: Apr 2013
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
yea there is no connector for 87A.
The power is in the 86 which is supposed to be ignition, and 30 which as stated is HOT all the time.
So lets say i put in a fusible link with a 15AMP fuse on it and it pops, and then i disconnect the fuel pump connector and if it were to pop again. What does that mean? Its hitting a ground somewhere or getting over loaded?
*** SIDE NOTE: If i am reading the schematic right 87 which is the orange wire goes from the fuel pump relay to ????
The power is in the 86 which is supposed to be ignition, and 30 which as stated is HOT all the time.
So lets say i put in a fusible link with a 15AMP fuse on it and it pops, and then i disconnect the fuel pump connector and if it were to pop again. What does that mean? Its hitting a ground somewhere or getting over loaded?
*** SIDE NOTE: If i am reading the schematic right 87 which is the orange wire goes from the fuel pump relay to ????
#29
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Joined: Aug 2011
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From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
yea there is no connector for 87A.
The power is in the 86 which is supposed to be ignition, and 30 which as stated is HOT all the time.
So lets say i put in a fusible link with a 15AMP fuse on it and it pops, and then i disconnect the fuel pump connector and if it were to pop again. What does that mean? Its hitting a ground somewhere or getting over loaded?
*** SIDE NOTE: If i am reading the schematic right 87 which is the orange wire goes from the fuel pump relay to ????
The power is in the 86 which is supposed to be ignition, and 30 which as stated is HOT all the time.
So lets say i put in a fusible link with a 15AMP fuse on it and it pops, and then i disconnect the fuel pump connector and if it were to pop again. What does that mean? Its hitting a ground somewhere or getting over loaded?
*** SIDE NOTE: If i am reading the schematic right 87 which is the orange wire goes from the fuel pump relay to ????
#30
Thread Starter
CF Veteran
Joined: Apr 2013
Posts: 1,153
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From: Rowlett, Texas
Year: 1988
Model: Cherokee
Engine: 4.0 Inline 6
I got that.... I checked the starter motor relay, the nut on the relay that is the battery terminal has power.... the orange wire which is the fuel ballast has no power... should I replace this relay?