Intermittent no start issue

lfhoward · **Posted:** Thu May 02, 2019 10:42 am

Hello LOST Jeepers,

I’m wondering if anyone has had this problem and solved it. A search of the web shows me that this can happen on any vehicle with the 3.7L V6 and not just KK’s. But there are precious few solutions at the ends of those threads.

My Jeep’s engine behaves normally under most circumstances, and always starts right up in the morning, or when I’m ready to commute home from work. However, sometimes when I run into the store for something and come back out 10 minutes later, the Jeep won’t start. It cranks and cranks and this shakes the Jeep because the engine is trying to start, but it doesn’t catch. And it doesn’t throw any codes. This is so intermittent that I can’t reproduce it at will, which means I can’t really go to a mechanic to have it diagnosed. It probably does it 1-2 times a month but I suspect it is happening more often with time. But it always starts eventually if I wait long enough.

Not to bias the thread, but I’ve read that people think it’s due to problems with the:

Scar0, I’m really hoping you read this (since you are Lost’s electrical guru :frankie:

). Or anyone else with this issue. That’s a long list of options and I’m hoping to narrow it down. The fact that it starts and runs normally under most conditions rules out the really expensive stuff, hopefully.

rotary_powered · **Joined:** Mon Nov 13, 2017 5:03 pm **Posts:** 19

I know that with some of the other Chrysler models, you can run into intermittent starting issues because of TIPM fuel relay issues.

I'm not sure how often it affects the liberties, but I believe its common with WK2 Grand Cherokees and the similar Durangos

This site has some information on a bypass/fixes
https://www.verticalvisions.com/tipm-fu ... tions.html

Lando-Liberty · **Posted:** Thu May 02, 2019 4:13 pm

There is also a known issue with the minivans that actually warranted a recall to replace the fuel pump, and or fuel tank. The sum, and substance of it all was the fuel pump would not / could not pump fuel after a short trip to the store on a hot day. it was believed that high pressure of the expanded gas in the tank would cause the the pump to hydro-lock itself. I had a minivan that did this, and would also stall after a fill up when you would come to a stop on a hot day. Chrysler would not fix the problem, even though my minivan was recalled by VIN, because mine had been modified for use as a handicap van.

So for you, if it was me I might replace the electric fuel pump, and the gas cap. changing the gas cap will ensure that your tank is venting correctly. I would only replace either of these items with genuine MOPAR parts from the dealership.

tomknight · **Posted:** Thu May 02, 2019 9:56 pm

My daughter's '08 had a very similar issue. In our case, it was very much like what we had just experienced in her (now former) X5.

So, we were pretty sure it was the fuel pump. If you let it run its course, the car will die completely, and not start at all.

We replaced the fuel pump, and it has run like a champ since. The pump was a little pricier than I expected in this vehicle, and you had to drop the tank to replace it. In the X5, there was a convenient (the ONLY convenient anything to fix) access point under the back seat. Not so here.

Anyways, that's what we did. It did not throw any codes. She would sometimes have to crank it a few times, or let it sit for a minute, then try again.

All good now with the new pump.

Scar0 · **Posted:** Fri May 03, 2019 1:32 am

Well here is the long and short of it.
Only happens on short trips, off and try to start after 10 or so minutes.
There are numerous KA owners with this happening on another forum I'm on.
So far in the last 4+ years no one has posted a definitive fix.
One said a new pup fixed the issue, another one said it did not.
One said the CAM and Crank sensors fixed the issue, several said it did not.

I have made several attempts to assist these folks, with the above list of possibles including removing the gas cap to relieve pressure, and several tests to run.
Again not one definitive fix or result.

The GC issue with the fuel pump relay problem is a different TIPM then the KK/KA uses.
If you can hear the fuel pump kick on when you first turn the key to the "run" position(not start) your fuel pump relay is working.

There was someone here on lost with the same issue a while back. If I remember right, again no results...
Sorry not much help but is what I know up to this point.

lfhoward · **Posted:** Fri May 03, 2019 1:17 pm

Hmmm. Thanks for the replies, everyone. I am not too enthused or encouraged to hear that there isn't a reliable fix for this sort of behavior. Since my Jeep doesn't do it all that often, and I can't reliably reproduce it by driving and getting up to temperature, then trying to restart, it looks like I'm going to have to wait a while until it becomes more of a problem. Hopefully I won't get stranded somewhere. I don't have the money to throw parts at it.

RepairPal.com estimates a new fuel pump, installed, runs for $600-$1050 in my area. Definitely not happy about that. Has anyone replaced their own fuel pump before? It's in the tank which would have to be dropped, and then there's dealing with a lot of flammable gasoline and fumes. Not really looking forward to this as a DIY project.

rotary_powered · **Joined:** Mon Nov 13, 2017 5:03 pm **Posts:** 19

Fuel pump is super easy, especially if you're lifted. I used two standard scissor jacks underneath the tank, and removed the lines in the back and front of the tank before removing the bolts and lowering it down. You'll have to stop half way down to pry off the fuel filler neck and remove some additional lines and electrical plugs from on top of the tank, but then it slides out and if you're tall enough you don't need to jack the jeep up. Some compressed air to clean off the pump assembly before removal helps to keep crud from falling in the tank, and a punch or flat head screwdriver and hammer makes removing the retaining ring easy.

However, if your problem is sporadic and intermittent, I would assume its not the fuel pump, those are sort of all or nothing type failure, or will show partial failure during full throttle, max fuel requirements.

teller34 · **Joined:** Thu Oct 26, 2017 9:36 pm **Posts:** 48

My daughters explorer sport trac had a similar problem. It started out doing it every once in a while and then stranded her. It wound up being a rollover switch. I think it is done on a relay on the Liberty. I wonder if the relay could be going bad and showing up sporadically when it gets hot. Does the fuel pump engage when it does this.

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Intermittent no start issue

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