crank but no start

[Jcam]

I have an 06 liberty 3.7 and today i tried to start it and It will just crank and crank but will not even try to start.

I have zero fuel pressure while cranking, I cannot hear the fuel pump turn on. my relays for the fuel pump and asd are clicking when i turn the key on. I tried swapping with other relays with the same P/N and I have the same result. I checked all fuses and they all are ok.

I have 1 volt across the pdc fuel pump fuse #14 and 1.9v while cranking. Im not sure if this is an efficient way to check it but i figure id add the info.

I have not checked spark yet. That is a plan for tomorrow. I pulled the IAC and it was not sticking.

I have no engine light and the only thing i can think of that can relate is that sometimes the car would crank, sputter, die and start right up again. I thought I was not just holding the key long enough.. but maybe not.

Id hate to have to drop the tank to find that the fuel pump was not bad..

Any advice would be appreciated.

Thanks

James

 

[teeje]

No fuel pressure, fuel pump. Not hard to fix. Pull rear carpet, access panel is right there. Replace the fuel filter while you're at it. Check your fuel pressure sensor as well. Tank does not have to be dropped. There is two black cargo strap things that are pop riveted in. Drill out those drives to pull the carpet up or find a way around that as you will have to find a different way to hold those cargo "things" down.

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[HoosierJeeper]

Jeep stopped the access door for fuel pump after 03 I think. 06 won't have one for sure.

 

[Jcam]

Thanks, ya 06 does not have the access door. but yes depending on the spark test tomorrow I'll have to just suck it up and drop the tank

 

[Billwill]

I have an 06 liberty 3.7 and today i tried to start it and It will just crank and crank but will not even try to start.

I have zero fuel pressure while cranking, I cannot hear the fuel pump turn on. my relays for the fuel pump and asd are clicking when i turn the key on. I tried swapping with other relays with the same P/N and I have the same result. I checked all fuses and they all are ok.

I have 1 volt across the pdc fuel pump fuse #14 and 1.9v while cranking. Im not sure if this is an efficient way to check it but i figure id add the info.

I have not checked spark yet. That is a plan for tomorrow. I pulled the IAC and it was not sticking.

I have no engine light and the only thing i can think of that can relate is that sometimes the car would crank, sputter, die and start right up again. I thought I was not just holding the key long enough.. but maybe not.

Id hate to have to drop the tank to find that the fuel pump was not bad..

Any advice would be appreciated.

Thanks

James

Not sure what you mean by measuring "across" the fuses...you need to put your Voltmeter Black negative lead on a good clean chassis point and the Red positive lead on either side of the fuse #14....you should get +12 volts shown there. If you get +12 volts on one side of the fuse but not on the other side then that fuse is blown!

If the fuse has blown then you are trying to measure Amps through your meter while on the DC Voltage setting....could possibly blow your meter up doing this...check your meter still works by putting it across the battery while on DC volts!:shrug:

 

[Jcam]

I get 11.9 volts on both sides of the fuse and 12.3 at the battery. Thanks

 

[Cpt Marvel]

Well if you've checked the fuse and it's good, and you've swapped out the relay, and your getting no sound from the pump (I'd have somebody else put their earball on it too) then next logical would be the pump or wires to it. I'd go for the pump. Get one of those manual squeeze siphon things you use for kerosene heaters. You can pull off the pickup tube and put a piece of rubber hose on it to siphon the tank. Trial and error on the length. Too long and the end will curl up over the gas. Too short and..you know. Floor jack or two with a square of plywood to distribute the load. Looks like a PITA, but not as bad as a long skinny tank like in a pickup truck

 

[M38 Bob]

Dont know about Jeep, but on GM vehicles you can almost always beat hell out of the bottom of the tank and get the pump to function one more time. Not a very scientific test, but effective.

Bob


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[Jcam]

I knew of that trick. That's the first thing I tried heh. .

I cranked the vehicle with the voltmeter on that fuse and it drops to about 8.5v while cranking. I assume this is not normal?

 

[belvedere]

it drops to about 8.5v while cranking. I assume this is not normal?

Sounds pretty low to me.

 

[flair1111]

i have an 06 and the access hole isnt there anymore. i dropped the tank. the hardest part is disconnecting the fuel fill hose and the smaller one beside it. other than that its pretty simple yet kinda annoying. have a buddy help or get a jack and straps. for sure drain the tank. i ran a hose into the tank after i disconnected the fill hose. the wire connectors are kind of tricky but not hard to undo once you realize how to do it. just be careful with them.

if you have access to a disc grinder, buy all means cut an access hole into the back of the jeep floor for future use AFTER the tank is removed. Fu#K jeep for sealing it up.

 

[Billwill]

I knew of that trick. That's the first thing I tried heh. .

I cranked the vehicle with the voltmeter on that fuse and it drops to about 8.5v while cranking. I assume this is not normal?

Yep seems pretty low..what voltage drop do you get over the battery...probably about the same which is not good. The voltage measured over the battery when cranking should not drop lower than about 10 volts..lower than that indicates a bad cell on the battery. If the battery voltage is fine...about 10 volts...then you have bad battery connections/earth connections causing the voltage drop elsewhere.

Low voltage stops the PCM/BCM/TCM etc. from working properly!
You can try jumping pins 30 to 87 inside the Fuel Pump Relay socket...that should force the pump to run if the pump has not seized.

Any red LED SKIS light on the cluster while cranking?:shrug:

 

[Jcam]

i jumped pins 30 and 87 and did not hear the pump engage. I removed the pump from the tank and bench tested it without the module attached and it seems to work just fine.. I then attached it to the module and powered it up there and even the very connector that plugs into the pump itself and it did not work. Could the module be the issue or should it not work like that???

 

[Jcam]

UPDATE: Problem was the connector directly to the fuel pump. I had to get a new module/pump assembly. put it in and car starts and drives! thank you everybody for your input.