Good Reading...CP4.2 HPFP -- How You Can Keep Your CP4.2 High-pressure Fuel Pump Off the Scrap Pile

[Plongson]

Good reading here on these pumps. I kind'a wish I had a lift pump like on the old Dodge...looks like good insurance

https://www.dieselworldmag.com/diesel-technology/cp4-2-fuel-pump/

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[58Willys]

Very well written and informative article. Thanks for posting.

 

[BDinTX]

Ya good read, appreciate the link. It's interesting that BMW has a fancy way to purge air after a filter change. I followed the instructions to purge mine and it didn't seem to be very effective.

 

[MeekoDiesel]

Good reading here on these pumps. I kind'a wish I had a lift pump like on the old Dodge...looks like good insurance

https://www.dieselworldmag.com/diesel-technology/cp4-2-fuel-pump/

Our Jeeps do have a lift pump, it’s in the tank. Part number 68403974AC

If you hop in the Jeep with the door open in the garage or someplace quiet, with your foot off the brake so the engine doesn’t start cycle the start button to run. You will hear the in-tank pump cycle.

This is what the maintenance procedure has you do after a fuel filter change, cycle the lift pump 3 times to refill the empty filter area.

 

[BDinTX]

Our Jeeps do have a lift pump, it’s in the tank. Part number 68403974AC

If you hop in the Jeep with the door open in the garage or someplace quiet, with your foot off the brake so the engine doesn’t start cycle the start button to run. You will hear the in-tank pump cycle.

This is what the maintenance procedure has you do after a fuel filter change, cycle the lift pump 3 times to refill the empty filter area.

Yeah I'm pretty sure I did that, it wouldn't start, I did it twice more, and it started but wasn't running very smoothly. I thought it took a surprising amount of time for it to eventually smooth out. The only thing I can compare to though is my previous RAM trucks with the Cummins 5.9 and 6.7. Those were simple to get started again after the fuel filter change.

 

[RELBUS]

Glad Ram recalled the pumps on the 19/20 trucks. I had been using hot shots EDT every tank in hopes of keeping the pump alive. I have alot more confidence in the truck since the recall.

I will say priming after a filter change is a bit more of a pain on the push to start trucks compared to bumping the key on my 3rd and 4th gens.

 

[Plongson]

You are right, the lift pump is in the tank and I totally spaced it...that's what is priming the CP4.2
Thanks for the slap on the back of the head...lol

It's gonna be interesting to see what the "fix" is for the big money saving decision to switch from the CP3...

Bean counters can be such turds...

 

[BDinTX]

It's gonna be interesting to see what the "fix" is for the big money saving decision to switch from the CP3..

Good point - I JUST received my Artec belly pan today. Hopefully their fix doesn't feature a newly redesigned filter assembly (that Artec relocates with a new bracket).

 

[No Spark V6]

Yeah I'm pretty sure I did that, it wouldn't start, I did it twice more, and it started but wasn't running very smoothly. I thought it took a surprising amount of time for it to eventually smooth out. The only thing I can compare to though is my previous RAM trucks with the Cummins 5.9 and 6.7. Those were simple to get started again after the fuel filter change.

First time I did mine I followed the manuals recommendation and it took a while to start. Second time I primed it 10 times and same thing, tons of cranking before starting. Third time same as the second. I'm convinced it doesn't matter how many times you do it. Next time I'm debating priming, letting it sit then priming again.

 

[BDinTX]

It seems like the air is trapped in the system and has to go through the pump. Maybe their fix will be a valve to burp the filter housing....

 

[the_jeepeo]

First time I did mine I followed the manuals recommendation and it took a while to start. Second time I primed it 10 times and same thing, tons of cranking before starting. Third time same as the second. I'm convinced it doesn't matter how many times you do it. Next time I'm debating priming, letting it sit then priming again.

Great article and I’m glad this has morphed into a discussion about primed starts after a water separator/filter change.

I get the same results as No Spark V6.

Additionally, I get to prepare for questions from surrounding people about why my new bada$$ Jeep is struggling to start.

My approach is to respond with every agonizing detail so they think twice before reflexively asking a question they really didn’t want the answer to

Quick tip: Budget an extra 10-15 minutes when doing the WSFF replacement to drive it around at the end to make sure fuel delivery systems have certainly reached normal status.

Avoid what I did which was turn off engine 10 seconds after getting it running, go wash up, leave an hour later and have the long crank happen again.

Here’s footage of the start after diligently priming 10 cycles. Let it run for 10 seconds, shut it off, hour later with no priming cranked the same amount of time before starting. It’s been 4 months since and all starts have been ideal especially after starting a Hot Shots regimen.

 

[21JLURDG]

Good reading here on these pumps. I kind'a wish I had a lift pump like on the old Dodge...looks like good insurance
https://www.dieselworldmag.com/diesel-technology/cp4-2-fuel-pump/

Previously disccussed:
https://www.jlwranglerforums.com/fo...uel-pump-recall-announced.102876/post-2136102

 

[Frostbit]

Has anyone gotten their replacement recall pump yet. Our dealership says there are none coming in. It's been over a year since I got the recall notice.

I do use Archoil 6200 additive and have about 36,000 miles on my 2020 wrangler.

 

[Tank the Jeep]

My dealer put me on the recall list for November 2024.

 

[Eischman]

I put in for one at the dealer I bought it from the first week in Jan and had it replaced last week, another large dealer I talked to said they are only allowed one pump per week, no matter how large or small the dealer is.
As far as additives I use the same that I use in my Duramax, Diesel Kleen (silver bottle) or Hot Shots, Diesel Kleen boosts the cetane 6 numbers and Hot Shots 7 numbers.
I saved a bunch of those little gas line antifreeze bottles with the skinny necks and transfer the additive into them, easier to get it into the tank.
...and thank God my Duramax has the CP3 not 4, and I did install a lift pump with filter when I bought it with 6000 miles on it!

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