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Fuel pump issues, no power to pump?

41K views 70 replies 16 participants last post by  Yttrium 
#1 ·
Sorry I'm not searching around for this problem, I'm on my cell phone on the middle of no where with no Internet so this is my only way takes forever to load pages, anyway about a month of go my fuel pump went out I guess, my car wouldn't start no more said I was on empty with a full tank of gas, well I went out n bought all new hoses tanks straps fuel pump, everything. I finally get everything together n I go to start it n it says its empty on e not starting n I put 3 gallons in it. I checked all my fuses, connections everything is fine. I literally have no clue what could be the problem, I really need some help. My jeep is a 97 jeep grand cheroke 4.0 I6 thank you.
 
#29 ·
Yes lip, I just cleaned up my pcm plugged everything in all nice, went to see if the the Gage's work/cel would come on nope nothing turned it off n unplugged the CPS from the plug not where it goes in because that's a ***** to do. Still doing the same, I've notice with my ground that goes to the fender it's completely covered on green corroded stuff, it's all the way threw the wire, could this be my problem? Maybe. Or maybe it's that n the pcm is dead n jeeps are getting stupid haha
 
#32 ·
Okay I replaced the cord that was poop on my fender ground n I checked the other one n it's all good n still no start, n the engine light doesn't come on when I turn the key. So is my computer just ****ed? I checked all my sensors everything good. So when I turn the key over to where the power is on all the lights come on besides the check engine light n none of my Gage's move. So if anyone can help me from there please. :( because I'm about to go buy a new computer, but I don't want too if its not it.
 
#34 ·
Look at the ground near the coil. I think that's where the PCM is grounded. Clean it up. Same goes for the one near the dipstick on the side of the engine block. You very well may need a PCM, but I'd make certain I cleaned all those connections up first. Double check the integrity of those battery cables too.....especially the factory clamps. They suck.
 
#35 ·
Zeejay yes all fuses are perfect, I did disconnect the crank n o2 sensors back n forth n still nothing, oldfrog I replaced the ground n bolts into the fender next to the battery n I cleaned up the ground thr runs under the coil, but I didn't know there was one by the dip stick. When I get home ill go back under there n clean that one up also, yes the clamps do sick, but I went out n bought new ones a while back. Because the old ones were horrible lol.
 
#36 ·
Okay so after all this time, finally had the money to replace my pcm, still not starting but the dash gauges are working again, cel comes on when turning key over also with the codes n saying I have gas now so that problem is fixed but now I have to figure out why it's not starting. So it was never the fuel pump, there's gas in the rail so that parts good so I guess there's no spark. So what could it be? Everything is basically brand new, spark plugs, wires, cap, rotor, pick up coil(cam sensor), ignition coil. I did buy a crankshaft position sensor last year from autozone because the old one was going bad. Could that be the main problem after all? Please someone get back to me, is there anyway I could test the crank señor? So I don't have to waste any more money. Thank you
 
#37 ·
I hate that you bought another pcm before finding any other issues. Hopefully NOT....but whatever issue you had to begin with might have fried yet another PCM.

As far as having an autozone crank sensor, I will tell you that it's the general consensus around here that you use ONLY Mopar crank sensors. But there may be hope yet.

Watch these:



 
#38 ·
Great, well it seems to be working still so it's not dead yet lol but I'm going to replace the crank sensor with a dealer one next week so I hope it will start I've been broken down for so long, I have a kid on the way, I need to fix this jeep so I can find a better job n start a better life. I've put alot of money into this jeep I would die if I had to end up junking it. What other common issues could this be? Everything is basically new, which kills me why it won't start. Everyone I talk to about it in person just seems completely retarded. I've researched so much online, tried so many things. Replaced this n that, I miss my jeep.
 
#40 ·
For what it's worth, I know a lot of people on here will only use Mopar sensors and the general consensus is that the ZJ will have problems with anything but Mopar.

None of my sensors are Mopar. Just a hodgepodge of Autozone and RockAuto. Runs fine. The O2 sensor is a NTK but I had a Denso before that and a Bosch before that. I couldn't tell the difference. You pay your money and you take your chances.

Of course my VIC also works fine, maybe I just have a lucky ZJ.
 
#43 ·
I had the exact same issue on my 93 2 weeks ago.It kept blowing the 30amp fuses,so I changed out the PCM and another 30 amp fuse and presto!Problem solved.Glad I didn't have to replace the fuel pump again.
 
#45 ·
Im gonna start from the very beginning, as I was driving the jeep everything went out and it died. After about 1 hour it started back up, I was driving for another 20 mins, died again, after about 3 mins it started again. once I got back to my girls n parked it. Woke up the next morning, went to go start it. Nothing just dead. was reading no gas when I had a full tank! well finally got it pulled to my house while it sits there! I ended up replacing the fuel pump, wasn't the problem. there was no power to the pump, so I hot wired it. Still wasn't starting. Saw that the CEL wasnting coming on when I would turn it on and all the gauges weren't working. So I cleaned all the grounds, fuses n relays, pulled almost every wire out checked everything n still no start. Said **** it n replaced the PCM, still not starting. But the dash is working again n its saying I have gas. I checked to make sure there was pressure in the rail, there is. my whole tune up is from kolak got it in march. Along with a new cam sensor, well I was using a light test on wires seeing if I wasn't getting power to all my things n noticed that theres power going to everything, so that's good. I checked my coil n seen there was no power coming out of it so I pulled that out n took it to get it tested to make sure. Well it was fine, so something is causing it to not shoot the juice out n I do not know what, my crank sensor is over a year old from autozone. I don't think that would go bad this soon but then again idk. My PCM was dead I guess because everything that didn't work on the dash does work now. my o2 sensors are brand new from this year also, check the wires for them. ive been looking around about the alarm could be causing it from not starting. When I lock my jeep with the keyless remote the red light for the alarm doesn't come on no more. Have no clue why it always has work, so I rolled my window down n locked it n opened up from the inside to see if the alarm would go off like it used too n nothing, so my alarm is off? or got blown up or something. So that could be causing this whole starting problem? idk I need help ive done a lot n spent a lot of money trying to fix what I can n it sucks.
 
#46 ·
It sounds like something is a miss with the security system. Usually will cause a momentary start, then a shut down. The BCM sends a status signal to the PCM and there is no way to fool it. Try locking and unlocking the passenger door with a key.

Sounds like what you are describing at the coil is a loss of the signal from PCM. My advise is to check the crank sensor with a meter.

Does the CEL come on for 3 seconds when the ingnition switch is placed in the ON position?
 
#47 ·
Agree on checking the crank sensor with a multimeter on the disconnected female connector/plug to the sensor itself. With the meter set to one of the lowest ohm settings, and locking tab on the connector up, make sure you place the black probe on the middle B pin (ground cavity) and red probe on the right C pin (power). The reading should be "open", same as if the probes weren't touching anything, and any resistance at all indicates you have a bad crank sensor.

When completing this test you may also want to move the crank sensor connector from the passenger side to the drivers side to see if the readings change. On one of my bad crank sensors the reading on the passenger side was good but on the driver's side it read bad with resistance. Turned out the wires which make a sharp turn coming out of the crank sensor itself must have been shorted together.

As already mentioned aftermarket crank sensors are a crap-shoot and only go with Mopar sensors. I learned this harsh lesson with 2 new aftermarket crank sensors which drove me nuts since they only cured my stall/no-start problems part of the time. Once I went to a Mopar crank sensor my problems were resolved. Not saying this is your particular problem, since the electronics on these ZJ's are so complicated, but the test is worth a try. Good luck!

Note: test is for 4.0 & V8's.
 

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#49 ·
Those multmeters are a lot less expensive than you may think Tttruim and eventually you're going to need one to troubleshoot electrical issues/problems on your ZJ. Walmart sells some for $12-$15 and I paid $20-$25 for the below GB one at my local hardware. Comes in real handy for testing continuity/AC current around the house in addition to continuity/DC current on my Jeeps.

http://www.tooldex.com/gardner-bender-gdt-11-digital-multimeters-85813.html

Walmart also sells a set of red/black jumper wires with alligator clips for attaching the probes to connectors/grounds for $3. Would suggest buying a set since they come in real handy in using with a meter.

We can help guide you how to use one and there's plenty of youtube videos out there if you do a search. Good luck.
 
#50 ·

"Walmart also sells a set of red/black jumper wires with alligator clips for attaching the probes to connectors/grounds for $3. Would suggest buying a set since they come in real handy in using with a meter.
"

If you own a ZJ, you WILL use these eventually. Best money I ever spent.
 
#51 ·
Got a crankshaft sensor from the dealer, replaced it n still no start. had it on the jumper cables because the battery was dead, turnt key over just cranking, no start n then the check engine light came on its putting out code 54 now, so something to do with the cam sensor. -_- n now the vic is saying check battery! one problem after another.......
 
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