97 xj 4.0 ax-15 np231. Jeep has 48 psi of fuel presure and has a loss of power and backfires through the throttle body. Any ideas? It also throws a code saying bank 1 running lean. Any help greatly apreciated. Also has both brand new o2 sensors within the last 2 months.
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97 xj running lean popping through intake
- Thread starter green95xj
- Start date
Digger87xj
NAXJA Forum User
- Location
- Buffalo Creek/Lakewood CO
sounds like it's time to change out the filter/regulator assembly that is on top of the fuel pump module.
just because it has good pressure does not mean the volume is there.
just because it has good pressure does not mean the volume is there.
90xj06
NAXJA Forum User
- Location
- Peabody, MA
if you can check the fuel pressure when its running lean.
joe_peters
NAXJA Forum User
- Location
- Grants Pass, OryGun
1. Pull the plugs and read their condition, Google "reading spark plugs".
2. Post back with your results.
2. Post back with your results.
birchlakeXJ
NAXJA Forum User
- Location
- Melrose, MN
Backfiring and code verify a lean condition.
Inspect all exhaust hardware closely for leaks (manifold, etc).
Get a fuel pressure gauge and get a reading from the schrader valve on the fuel rail. For a 98, you should have 49.2 psi plus or minus 5 psi. It could be something else, but ruling fuel pressure in or out is something that should be done early in the troubleshooting process.
Inspect all exhaust hardware closely for leaks (manifold, etc).
Get a fuel pressure gauge and get a reading from the schrader valve on the fuel rail. For a 98, you should have 49.2 psi plus or minus 5 psi. It could be something else, but ruling fuel pressure in or out is something that should be done early in the troubleshooting process.
JJacobs
NAXJA Forum User
- Location
- Fort Collins CO
This could also be the infamous distributor drive gear roll pin in action. It only takes a minute or so to pop off the distributor cap and give the rotor a twist, should be tight.
Jamescad04
NAXJA Forum User
- Location
- Charlotte, North Carolina
My S-10 was recently backfiring through the intake and it wound up being the 02 sensor might want to test that.