Matt Macchiarolo

Turn the key to On, wait a couple seconds before you crank the starter. You
should be able to hear the fuel pump pressurize the system. I think there is
a check valve in the fuel system that maintains pressure, and if its
malfunctioning it will bleed down when sitting.

Wouldn't rule out a faulty crank position sensor, either. But more likely
it's a fuel pressure issue.

"Ken Shackelford" <ken.shackelford@ugs.com> wrote in message
news:e75d7$433ecc79$927ac816$14650@FUSE.NET...
> Troy wrote:
>
>> How long does it sit until you cant crank it? I've heard something about
>> the fuel injection rails on them but don't know anything for sure.
>>
>> Troy
> Actually, it always cranks, just won't start consistently. This happens
> if it sits for a little while, like say, an hour or even a little less.
> Once it starts, it runs fine.
>
> Thanks,
> K.

Matt Macchiarolo

Turn the key to On, wait a couple seconds before you crank the starter. You
should be able to hear the fuel pump pressurize the system. I think there is
a check valve in the fuel system that maintains pressure, and if its
malfunctioning it will bleed down when sitting.

Wouldn't rule out a faulty crank position sensor, either. But more likely
it's a fuel pressure issue.

"Ken Shackelford" <ken.shackelford@ugs.com> wrote in message
news:e75d7$433ecc79$927ac816$14650@FUSE.NET...
> Troy wrote:
>
>> How long does it sit until you cant crank it? I've heard something about
>> the fuel injection rails on them but don't know anything for sure.
>>
>> Troy
> Actually, it always cranks, just won't start consistently. This happens
> if it sits for a little while, like say, an hour or even a little less.
> Once it starts, it runs fine.
>
> Thanks,
> K.

Matt Macchiarolo

Turn the key to On, wait a couple seconds before you crank the starter. You
should be able to hear the fuel pump pressurize the system. I think there is
a check valve in the fuel system that maintains pressure, and if its
malfunctioning it will bleed down when sitting.

Wouldn't rule out a faulty crank position sensor, either. But more likely
it's a fuel pressure issue.

"Ken Shackelford" <ken.shackelford@ugs.com> wrote in message
news:e75d7$433ecc79$927ac816$14650@FUSE.NET...
> Troy wrote:
>
>> How long does it sit until you cant crank it? I've heard something about
>> the fuel injection rails on them but don't know anything for sure.
>>
>> Troy
> Actually, it always cranks, just won't start consistently. This happens
> if it sits for a little while, like say, an hour or even a little less.
> Once it starts, it runs fine.
>
> Thanks,
> K.

Nick Hughes

Hi Ken,

I had a similar problem with my 2000 TJ Sahara. It occurred two or
three times the first year I purchased it (new). I would turn the
ignition, the starter would kick in, but the engine didn't catch. My
hunch was that the computer didn't turn on the fuel pump. To fix it, I
turned the ignition all the way off, then tried again.

One of those things the dealer could never reproduce. Probably a
firmware bug in the computer.

Nick

Ken Shackelford wrote:
> Hello,
>
> I have an '04 Unlimited with an annoying problem at startup. For
> the last couple days occasionally when I try to start the vehicle, it
> will crank and crank, but not catch. However, if I turn it off for a
> second and try again, it starts right up. It normally happens after
> it's been sitting a while. Any ideas where to look? I realize it's
> still under warranty, but I hate dealing with the dealer so much that if
> it's relatively minor, I'd rather give it a go myself.
>
> Thanks,
> K.

Nick Hughes

Hi Ken,

I had a similar problem with my 2000 TJ Sahara. It occurred two or
three times the first year I purchased it (new). I would turn the
ignition, the starter would kick in, but the engine didn't catch. My
hunch was that the computer didn't turn on the fuel pump. To fix it, I
turned the ignition all the way off, then tried again.

One of those things the dealer could never reproduce. Probably a
firmware bug in the computer.

Nick

Ken Shackelford wrote:
> Hello,
>
> I have an '04 Unlimited with an annoying problem at startup. For
> the last couple days occasionally when I try to start the vehicle, it
> will crank and crank, but not catch. However, if I turn it off for a
> second and try again, it starts right up. It normally happens after
> it's been sitting a while. Any ideas where to look? I realize it's
> still under warranty, but I hate dealing with the dealer so much that if
> it's relatively minor, I'd rather give it a go myself.
>
> Thanks,
> K.

Nick Hughes

Hi Ken,

I had a similar problem with my 2000 TJ Sahara. It occurred two or
three times the first year I purchased it (new). I would turn the
ignition, the starter would kick in, but the engine didn't catch. My
hunch was that the computer didn't turn on the fuel pump. To fix it, I
turned the ignition all the way off, then tried again.

One of those things the dealer could never reproduce. Probably a
firmware bug in the computer.

Nick

Ken Shackelford wrote:
> Hello,
>
> I have an '04 Unlimited with an annoying problem at startup. For
> the last couple days occasionally when I try to start the vehicle, it
> will crank and crank, but not catch. However, if I turn it off for a
> second and try again, it starts right up. It normally happens after
> it's been sitting a while. Any ideas where to look? I realize it's
> still under warranty, but I hate dealing with the dealer so much that if
> it's relatively minor, I'd rather give it a go myself.
>
> Thanks,
> K.