• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Look...fuel pressure test video

Distended

NAXJA Forum User
Location
AZ
With key in "On" position gauge needle strikes @ 50 psi for a moment then bleeds down to 40 psi. At idle needle flutters between what looks like 49-50 psi? Even took gauge off of air filter housing to ensure that it was not engine vibration causing needle flutter. The engine had been run about one & a half hours earlier for about 12 miles. Is this much needle flutter normal? Fuel pressure gauge is brand new so hopefully, it's not faulty. Also, I reran test and saw same flutter.

FWIW...'96, 4.0L, ax-15

Could this mean bad fuel regulator or leak in lines? Or just bad test procedure or no worries...just chill-ax?

http://www.youtube.com/watch?v=wOMLxi8ElXk
 
Last edited:
Factory specification is 49 psi, +/- 5 psi. Looks good to me.
 
Factory specification is 49 psi, +/- 5 psi. Looks good to me.

Thanks for reply. I agree that the pressure looks appropriate, it's the flutter and bleed down with the key "on" that makes me wonder if there are any pressure irregularities in the system. :dunno:
 
Additionally, while performing a volume test I collected about 3.5 ounces of fuel over 15 seconds or .233 ounces per second. Don't know what the designed operating rate is...but, does anyone think this rate could indicate a clogged fuel filter?
 
If it ain't broke, don't fix it. I have owned 5 Cherokees, and never have checked the fuel pressure or delivery on any of them. The one in the driveway has 178,000 miles.

Is your Cherokee having an issue or odd behavior ?
 
If it ain't broke, don't fix it. I have owned 5 Cherokees, and never have checked the fuel pressure or delivery on any of them. The one in the driveway has 178,000 miles.

Is your Cherokee having an issue or odd behavior ?

This is my first Jeep with the 4.0L inline six so I am not sure if the behavior I believe I sense is just par for the course or something to look into. From time to time it seems that while under load the engine skips a beat, so to speak, nothing insane, or may even be my imagination. Also sometimes the crank times seem excessive, again might be business as usual...dunno.

Given that, I wanted to get some data on the fuel system first. If the procedure in the video link was properly executed I could use the data from that procedure to point me in some direction.
 
Back
Top