vehicle vapor locking

[GilpinGuy]

I had hesitation problems with my old XJ and it was the fuel filter - I think it was mounted on the frame on the drivers side. I've had several Jeeps though...

Start with gas cap, then fuel filter, then go on to more complex (and expensive) stuff.

[blackford76]

Just
Empty
Every
Pocket!!

[SideShow Bob]

Does this only happen when you are low on fuel (1/4 tank or less) ?
If so you could have rust particles in your tank, and when fuel is low they are concentrated and clog the filter/strainer on the end of the pick up tube in the tank. Even if it is one of the plastic tanks this is a possibility due to buying cut rate gas or using older gas stations that still have the old steel storage tanks.

[HoneyBadger]

Just
Empty
Every
Pocket!!

Ya know, I've heard a lot of people whine about this, but I guess my Jeep experience was unique.

Sorry to take the thread OT...

in 2008 I bought a 95 Grand Cherokee Laredo with 161k miles on it for $2500. I left it stock and just used it to get around town and [occasionally] head up Mt Herman road or Rampart Range Road to drive some jeep trails. No rock crawling or anything crazy, but I did some offroading that scared the crap outta me.. Almost rolled a few times, at one point I got stuck with just 2 wheels making contact: my front left, and back right; there was about a 4 foot deep pit outside the driver's door, so I couldn't even get out to survey the situation. Ended up getting through it and finding an alternate route back through. I got stuck on a tree stump once because I wasn't paying attention and had to be lifted off by a REAL off-roader who laughed at me in my Laredo... My wife was driving it and got hit by a red-light runner, which totaled it in 2011. It had 188k on it then and still ran fine. During the 3 years I owned it I never took it into the shop for more than an oil change or tire rotation. When it was totaled, the insurance company gave us $2700 for it. I never had a complaint, and I wish I still had it.


....And now back to your regularly scheduled programming: Possible vapor locking problems for the OP.

[blackford76]

While you are checking fuel pressure, look at the injectors themselves. Specifically where the fuel rail hooks to them, and where they seat into the intake. The 'O' rings used to seal them were prone to failure. I would think that by now they have been replaced, but it won't hurt to look to see if any fuel is leaking past them.

Most likely a bad gas cap.

[GilpinGuy]

Man, the Jeep haters...

I had a '95 Grand (like HoneyBadger) that I traded in at 398K miles. Yeah, it was tired, but it ran fine. No major problems except the usual battery, water pump, etc. replacement stuff that comes with a seriously high mileage vehicle.

I've had 6 different Jeeps and have been very happy with all of them.

Frankly, I think that most sheeple just have lost touch with their vehicles and don't know how to maintain them properly. Proper maintenance = a properly running vehicle.

TANGENT: my VERY left wing boss at my old job once said at lunch after I mentioned that I changed the oil in my Wrangler "Oil change? Why would you change your oil? That's just stupid?" He had a Wrangler as well.

His opinion was that "changing oil" was a conspiracy by the oil companies so we use more oil. We never actually needed to change our oil. <sigh>

I challenged him of course, and his reply was "Well, my Jeep leaks so much oil, it's like I'm changing it all the time!"

My '99 Wrangler has almost 200K miles and doesn't leak/burn a drop. Silly libs....

[brutal]

...I challenged him of course, and his reply was "Well, my Jeep leaks so much oil, it's like I'm changing it all the time!"

Well, that was very green of him now wasn't it?

[DSull]

I had a similar problem on a Mazda and the gas cap went bad, go figure!

[HoneyBadger]

sort of NSFW for language...

[Danimal]

Awwww shiiiiiiiit....

hahahahaha!

Back to the OP.

1) Replace gas cap
2) Replace fuel filter (personally I would just do both of these at the same time unless you knew the filter has already been changed recently)
3) Check fuel pump discharge pressure and check proper operation of the back-pressure regulator. If the regulator is failing, you will have low fuel pressure and will cause the engine to fall on its face. If the fuel pump is failing then you will have the same effect.

Also I would run some fuel system cleaner for a couple weeks to clean the crap out of the injectors. When you run them at low pressures for a little while they tend to plug up more than normal. You might want to do this before you replace the fuel filter so that you don't crap up your new filter right away if there is a bunch of junk in the gas tank causing the problem in the first place.