Code p0192?

[KeZu01]

Still working on my clacking, turns out its probably ujoints on the d30, the spindle didn't move but when I run my hand up there the passenger ujoint has tons of play, so I got a pair of the 5-760x splicers ordered and will do those and other front axle service when they arrive.

But in the meantime I'm attacking my erratic idle and accompanying engine codes.
I had the tps code so I grabbed a new tps and that code hasn't come back. Seems to idle a little better but sometimes still idles too low at a stop, below 1k, and idles erratic. Now I have a new code! One I can't find much on.

P0192. Says on scanner fuel pressure sensor or something? Anyone had this on their xj? Advice? Like I said it seems to idle better with new tps, but maybe just my imagination. Still gets choppy and can feel it shake the whole vehicle at idle at least a couple times a day.

Thanks in advance xj-perts!

[Brasscatz]

Hmmm... with the idle issues and you mentioning the fuel pressure code, I'm thinking you need to try replacing your fuel pressure regulator. I bet that's the culprit right there!

[4.3LXJ]

I think that would be it. Not cheap though, it is in the tank and is part of the fuel pump assembly

[KeZu01]

Yes, looks like a chunk of change for that. So you think fuel pressure regulator and not fuel injectors? I found this on JeepForum:


"When your 1997 to 2001 Cherokee won’t start on the first try day after day, the first thing to suspect is a failed check valve on the fuel pump. The fuel pump check valve is supposed to hold pressure in the fuel line while the engine is off. The check valve is located on the fuel pump and located in the gas tank. A failed check valve allows the fuel to drain back to the tank. This results in the following symptoms:

SYMPTOMS

• Longer than normal cranking times
• Never starts on first try, almost always starts on the second try
• Rough idle for a few moments of idling
• Rough running for first ½ block of driving
• Little or no fuel pressure at the fuel rail test valve similar to this -

1- Key in on position; fuel pump primes for 2 seconds then stops. 0 PSI
2- Cranking over the engine. 2-3 PSI
3- Engine starts and idles for 20 seconds. < 5 PSI
4- Engine idles and fuel pressure creeps up to 45-50 PSI.


POSSIBLE CAUSES

• Failed check valve on the fuel pump in the gas tank.
• Leaky fuel injector(s) may be the true cause of your problem, but more likely they are simply contributing to the check valve issue."



Those Symptoms are spot on for what I am experiencing. But could it be fuel injector issue or is it most likely the check valve, considering my obd2 code? I know there is a procedure for checking to be sure, but what do you guys think would be the best guess?

[Brasscatz]

Well, injectors aren't cheap either, but an easier fix. Might go with the pump/filter/regulator because it's good to change them anyways and you'll have to do it sooner or later. Do them all at once because you have to drop the tank. Then I'd go injectors after. But that's just me. I'd go with what 4.3LXJ suggests, he's a mechanical Jeep guru with this stuff.

[4.3LXJ]

If you really want to nail this down, the procedure is to hook up a fuel pressure gauge to the fuel rail. If the pressure is not high enough then it is the regulator. If it goes up but bleeds down after the 2 second startup sequence, then it is the check valve. But in either case, the fix is the same. That is all in your fuel tank and is one assembly. It is too bad you cannot buy individual parts. Detroit cost cutting

[KeZu01]

Yea, that's what I was thinking. It's not hurting anything so I'll put it off, at least until I get some other items checked off.
At least its nice knowing what it is. I will just prime the pump before starting for now, it seems to help.