Hard to start.

2000 Jeep, 4.0L AW4. 130k miles on it.

Went wheeling and camping, and now I have this problem, I'll turn the key and let it crank for about 5 seconds, no start, do it again, no start, and they third time it starts right up, and runs strong.

I'm thinkin it must be fuel as i'm probably priming the system each time I turn the key.

I'll probably pressure check it here this week, any other Ideas though?

J

Try just turning the key to ON, then OFF, repeat three or four times, then try and start it.

Mine started doing that a while back. Cleaned the nss today and it starts like new now.

hghgrad said:

Mine started doing that a while back. Cleaned the nss today and it starts like new now.

Click to expand...

Nss
neutral safety switch?

Thats a possibility but it's more likely the pressure relief valve in the tank. They go bad A LOT! It's a little embarrassing when somebody is ridin shotgun but you'll be fine leaving it. The pump itself is probly fine, the relief valve gets stuck open or so I've been told.

Or leaky injectors... I just replaced mine with yellow 19lbs
Made a change.
I have hard starting too. I need to start looking to the tank

The NSS has a few jobs to do. First, it keeps the starter from cranking the engine over unless the transmission is in PARK or NEUTRAL. Guess it should have been named PNSS, but its too late to do anything about that now. It accomplishes this part of its job by interrupting the ground to the starter relay. Second, the NSS (PNSS) provides data to the TCU--transmission control unit--on the physical gear selected. Third, if adjusted properly, it completes the circuit so that your back up lights work when reverse gear is selected.

Note that the NSS (PNSS) has NO IGNITION INTERRUPT. It merely prevents the starter from cranking. If your engine cranks but won't start don't waste time with the NSS.

In a crank no start situation you need to determine the missing element. Fuel, air, compression, spark, all at the right time, at the right place, and in the right quantities.

XJ Eric said:

Thats a possibility but it's more likely the pressure relief valve in the tank. They go bad A LOT! It's a little embarrassing when somebody is ridin shotgun but you'll be fine leaving it. The pump itself is probly fine, the relief valve gets stuck open or so I've been told.

Click to expand...

Relief Valve? is that part of the Fuel pump or Fuel tank?

Sounds like this could be more possible, more info?

joe_peters said:

The NSS has a few jobs to do. First, it keeps the starter from cranking the engine over unless the transmission is in PARK or NEUTRAL. Guess it should have been named PNSS, but its too late to do anything about that now. It accomplishes this part of its job by interrupting the ground to the starter relay. Second, the NSS (PNSS) provides data to the TCU--transmission control unit--on the physical gear selected. Third, if adjusted properly, it completes the circuit so that your back up lights work when reverse gear is selected.

Note that the NSS (PNSS) has NO IGNITION INTERRUPT. It merely prevents the starter from cranking. If your engine cranks but won't start don't waste time with the NSS.

In a crank no start situation you need to determine the missing element. Fuel, air, compression, spark, all at the right time, at the right place, and in the right quantities.

Click to expand...

Yes, I understand that, i've replaced one before, So this SHOULD mean it isn't the NSS because it cranks nice like.

Actually it DOES mean it's not the NSS because that simply can't be the cause of an extended crank time.

Exactly correcto mundo.

There were some major changes to the fuel system starting in 96. In 96 the fuel pressure regulator on the fuel rail was moved to the tank, and one-year bast*rd fuel pump assembly was used.

In the 97+ they switched to a plastic fuel tank, moved the opening for the fuel pump assembly to the top of the tank so you have to drop the tank to get access to it. On the top of the plastic tank is a funky FPR/filter/check valve assembly. This is the likely culprit as the check valves fail FREQUENTLY. When they fail the fuel is allowed to drain back into the tank, so you are starting with zero pressure OR fuel in the lines--well, probably still a little bit in the low areas.

So, you can key ON, key OFF, key ON, key OFF, key ON and START. That should cycle the fuel pump for 1-second each key ON and that should pressurize the system enough to give you a good start.

You can replace the offending part:

That's $86 at rockauto.com, and you have to drop the tank to get to it.

Ah good info...

Guess i'll just leave it be, sounds like it won't really leave me stranded any time.

So I worked on a 98 today that has a hard start issue. Threw the fuel pressure gauge on it and saw the pressure go to single digits in seconds when cutoff, or immediately after a prime w/o start. So the check valve is part of the fuel pressure regulator? The above pic is SMP318, $77.79 pre-disco.

Good info... I have the same problem... thought it was the CTS... now I know!