ANY 05 JEEP G.CHEROKEE MECHANICS

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WAYNE0

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I hav e 05 jeep with a 5.7 some times the fuel pump will not run & it will not start. Its random. I replaced the fuse, relay, battery & alternator.
 
Check all of your electrical connections to the pump first. Also check the fuel pressure reading when it IS running to see if it's within specs. (It will help a lot if you have a factory service manual, or access to specs) Make sure it has a GOOD ground. It may be the pump is going bad too! If you do need to replace the pump, spend the money & get a good one. (Carter, Delphi, Etc.) Don't get a cheaper one like an Airtex or anything like that, they just don't last & it's a lot of work to replace them, because they are in the tank. Check ALL your connections FIRST.
 
Hard to say without seeing and troubleshooting it in person. Could be a number of things. When it doesn't run, lay underneath and beat the bottom of the gas tank with a rubber mallot close to where the pump is and have someone turn the key to ON position and see if the pump runs. Sometimes the shock of hitting the tank will "jump start" the pump...if that works then you need a new pump.
 
check out the tsb on putting a different relay in the fuse box. a lot of shops are doing that as mother mopar won't do the recall on everything. i have a part number of the relay package that may help you, may even have the recall/tsb number. best thing if you have a mechanic buddy at the dealership, ask him. maybe someone will chime in.
 
check out the tsb on putting a different relay in the fuse box. a lot of shops are doing that as mother mopar won't do the recall on everything. i have a part number of the relay package that may help you, may even have the recall/tsb number. best thing if you have a mechanic buddy at the dealership, ask him. maybe someone will chime in.

This doesn't apply to his vehicle. His has an external fuel pump relay. I have had to perform the modification you are referring to on a couple of Town & Country's.
 
although it does not apply to his unit, shops have been doing this to rams and jeeps with success and it seems to work well.
 
What is the mod? A different relay would seem to only change the trigger value? I got a '12 Caravan.....Curious. Our fleet mechanic would tell us to go under and kick the tank too if it would not start, has worked for a few guys...not mine.
 
although it does not apply to his unit, shops have been doing this to rams and jeeps with success and it seems to work well.

This is done on vehicles where the fuel pump relay is internally part of the circuitry of the Totally Integrated Power Module and not replaceable. His GC just has a normally replaceable (plugged in) fuel pump relay.
 
What is the mod? A different relay would seem to only change the trigger value? I got a '12 Caravan.....Curious. Our fleet mechanic would tell us to go under and kick the tank too if it would not start, has worked for a few guys...not mine.

The repair, on applicable vehicles, is to disable the circuit for the internal relay and rewire an externally mounted relay into that circuit.
 
Got up this morning & went to the store to get a few things. When i got back & a few minutes later i tried to start it & no go. When its going to start i can tell i can hear the pump for a few seconds. I took the fuel pump relay & fuse out & spray electrical cleaner in where they plug in still no go will not start. Got under neath & smacked the tank with a rubber hammer still no go. Looks like im replacing the pump. Im not good with wiring & checking things.
 
check out the tsb on putting a different relay in the fuse box. a lot of shops are doing that as mother mopar won't do the recall on everything. i have a part number of the relay package that may help you, may even have the recall/tsb number. best thing if you have a mechanic buddy at the dealership, ask him. maybe someone will chime in.
I replace the relay & fuse. I got them at my local NAPA
 
Did it work?
At that time yes that was in Dec of last year but only lasted for a month then back to not starting In the mean time it wouldnt start without jumping it. I was told on line that the fuel pump wasnt getting enough volts due to a weak battery. I replaced the battery & alternator in Dec. Its been good ever since until yesterday. Its back to not starting again. Like i said its random. Could the relay gone bad ? I got the cheapest one they had at NAPA
 
One more thing you can do, when it doesn't want to start, have someone hold the key in the crank position, while you smack the tank. I know you hit it before, and it didn't work, having the key on makes a difference, because voltage and ground are then both applied. Either way, it most likely needs the pump. Don't buy a cheap one...
 
I've had several where the short fuel pump wiring harness above the tank have corroded and caused the same type of condition described. It's usually the "upper" connector where the pump harness plugs into the body (4 pin), and can be accessed without dropping the tank. Just look for the harness at the top of the tank on the driver's side and check the pins for green fuzz.
 
One more thing you can do, when it doesn't want to start, have someone hold the key in the crank position, while you smack the tank. I know you hit it before, and it didn't work, having the key on makes a difference, because voltage and ground are then both applied. Either way, it most likely needs the pump. Don't buy a cheap one...
I read on line you can bypass the relay with a jumper wire not sure how to go about doing it cant find any info by doing that if the pump runs then its not the pump
 
I read on line you can bypass the relay with a jumper wire not sure how to go about doing it cant find any info by doing that if the pump runs then its not the pump
I may not be the best one to give advice on this, but a jumper w/ 2 alligator clips, right in the relay box? I dunno. Pure speculation
 
For those not knowing how to bypass relays- most relays have numbers by their terminals. Look real closely, and find 30 and 87. Find that respective position where the relay plugs in, and jump the two together.
 
I got on line & found a guy who cut a whole in the floor under the rear seat to get to the fuel pump so you didnt have to drop the tank. So that is what i just did a few minutes ago. Its going to be fairly easy to get to it now. I got done with cutting the whole & thought mmm how am i going to get to the parts store. So just for the heck of it i tried to start it & bingo it started. Like i said its random. Still going to replace the pump.
 
Well i just replaced the pump assembly. Hope that fixes it lol Thank you all for the ideas & responses
 
Whatever you do, stay away from @Cope

He'll fix your fuel pump problem, but leave your rig looking something like this

9913125.jpg


4859278f8a327b3464a9076455834956.jpg
 
Whatever you do, stay away from @Cope

He'll fix your fuel pump problem, but leave your rig looking something like this

View attachment 1715877277

View attachment 1715877278

I'm sorry Sir.

My work is better than that.

(Altho that guy is good.)


But now that you have my attention let me scroll back and see if I can help.

:)

20220224_213842.jpg


Turns out its fixed.


Honestly at this point, I dont even know what I want in a daily driver.
 
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