As you have the WHEREWITHAL but not the part - why not go to jeep for one OR a part store like NAPA ? Schraider valve code, and tool.

 

Sometimes just tightening a Shraeder valve will clear up a leak.

 

Called the dealership. Part was not individually available, only the discontinued entire fuel rail no longer available. No parts store has something specific for the 4.0l. Lots of generic online, but I don't know the specs for what size this valve is, so I don't know what generic part to buy. I have already removed, cleaned, and reinstalled the valve core with no change, hence the reason I am here asking for help.

Thanks for the suggestions, keep em coming!

 

I would think a tire valve would work just fine. I don't believe the neoprene rubber is any different due to gasoline. These valves are readily available with the tightening tool as a kit. Others chime in.

 

That's not a chance I'm going to take with a gasoline valve that if it fails is going to spray gas directly on to the exhaust header and start a fire. I have looked at some vehicle specific kits and generic ones and every one of them comes with the warning to only use a valve core specific to the gasoline test port as the gas could disentegrate washers from AC line test port valve cores. Plus, the outside diameter is larger than a tire valve, so I would imagine that the core would be larger too. Might be wrong, but it makes sense to me.

I've never removed the fuel rail valve core, but I don't think it's anything special. Release fuel rail pressure, remove valve core and take a look..

That being said, I'd start with what highlonesome suggested: slightly tighten the valve core and check if the leak stops.

Already did, as mentioned in my last post. No luck, still seeping. It might have slowed down a little, but it hasn't stopped and I don't want to overtighten and strip the core.

I know I can get cores for a variety of valves. I just don't know the size, the standard, for this valve. If someone knows the actual name (NPT size 8, or GM Standard X, or whatever), then I can buy the correct replacement. Since they often come in packs of 5 or more on Amazon, I'd rather not end up with 25 unusable cores and 4 that I no longer need because I bought 6 different sizes hoping one of them would be the right one. If no one knows, no biggie. Just thought I would pick some brains and see what came up.

 

I've never removed the fuel rail valve core, but I don't think it's anything special. Release fuel rail pressure, remove valve core and take a look..

That being said, I'd start with what highlonesome suggested: slightly tighten the valve core and check if the leak stops.

 

I've been through this before many years ago, so I did a little looking around to jog my memory. You surely will need a valve core rated for FI. It's possibly an 8mm valve. What I would do is pull the core and take it down to Napa. There is a chance the GM core will fit.

 

If the weather holds and I can ride the motorcycle, I'll do that. This is my sole means of transportation other than my bike, and it has been raining something fierce the last few days, so pulling the core for comparison has not really been an option. Not sure where the closest Napa is, but I did find a pick n pull fairly close that might end up being the solution.

 

I know this is an old post, but this comes up at the top of the Google search on this topic. This is the shrader valve replacement for the WJ Fuel Rail, It's an AC Delco pat #88894338

Amazon.com: GM Genuine Parts 88894338 Fuel Injection Fuel Pressure Relief Valve : Automotive

Buy GM Genuine Parts 88894338 Fuel Injection Fuel Pressure Relief Valve: Pressure Regulators - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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