Only one way to know fuel pump is ok is checking rail pressure a recent swap proves nothing

What are live data short and long term fuel trim values

 

What brand O2 sensor was used? What brand CPS was used?

Anything other than NGK/NTK O2 sensor could be causing you problems. Especially Bosch O2 sensors are notorious for causing problems in TJs,

Check your fuel rail pressure despite having a new pump. You should have 49 psi. As far as the pump goes, Bosch or Mopar is what you want there.

 

Check for a manifold vacuum leak. Also no way in hell can they over bore the engine to point of injectors not handling it.
Check fuel pressure and there is a way to test volume too.

 

Well dang, that was fast.

I'll start with checking fuel rail pressure. It's a bosch o2, but if the O2 was reading lean, wouldn't it be dumping fuel in and fouling up the plugs? The plugs look like it is actually lean..

The fuel pump was changed earlier last year and I don't remember the brand right off, but it wasn't an auto store special or anything.

The CPS was an Airtex/wells sensor

I checked the manifold, but I'll double check it when I check the fuel pressure

 

Found my fuel pump receipt, it's a bosch as well

I never mentioned that the O2 sensor was reading lean, I just know form personal experience (98 2.5) the PO didn't do the best at maintenance. I had constant O2 sensor codes despite having the receipt still in the Jeep from the PO of a brand new sensor. I ordered a NTK from RockAuto Parts Catalog and have had zero issues since installing that. That one sensor cured 1) the CEL coming on constantly, 2) a slight miss that I had around 2K rpm when cold 3) seemingly worse than what I should have been getting MPG, I went from about 10 MPG to about 14. I have 6" lift and 35" tires so I know I am blessed to be getting 14 and I'm happy with that.

As for the CPS, I would recommend a Mopar sensor. I fought issues with an advance auto brand (BDM maybe?) and finally ordered a Mopar sensor from Mopar Parts | Dodge Parts | Jeep Parts | Chrysler Parts | Ram Truck Parts | Wermopar and have had zero issues since that.

as long as you get the 49 psi at the fuel rail, I would say you will be good to go with the Bosch pump. That is what they came from the factory with and have proven time and time again to be a suitable replacement.

 

Found my fuel pump receipt, it's a bosch as well

 

Ah I see what you're saying. I'll try the ntk sensor then I guess if the fuel pressure is right. More money more money more money! Haha

 

OK so I rechecked the codes and the p0171 lean code has gone away. However I still have 1391 (intermittent loss of cmp or ckp) and 1388 (auto shutdown relay). Since I replaced the crank position sensor, should I replace the cam position sensor?

 

I wouldn't just throw parts at it anymore. I would test the crank sensor that you replaced. Many times the parts house sensors show signs of not working properly right out of the box.

As for the lean condition no longer showing... That is exactly what was going on with my Bosch sensor. Sometimes it would throw a code and sometimes it wouldn't.

 

Oh really? Seems odd they'd send out defective parts. I'll check it though

Noted on the lean code, if it comes back I'll replaced the sensor with an ntk. Right now it just needs to stay off long enough to pass emissions, haha

 

Oh really? Seems odd they'd send out defective parts.

Evidently, you are not terribly familiar with "offshore manufacturing." "Quality" is not job #1.

 

CKP tested good, and I don't see any damage to the harness or loose wires. Any other ideas?

 

Also, the codes only seem to come back after I start the car a second time.

 

I read that a bad distributor ring could cause it, so I'm going to borrow the distributor from my buddies '97 and see if that fixes it tomorrow. Fingers crossed...

 

Any update to this problem?

 

I ended up just ordering a brand new distributor with a new cmp that came in a couple days ago but I got snowed under with work and haven't had the hour or 2 to install it. I'll see if I can get some time to put it in the afternoon or tomorrow.

 

I got a chance to swap out that distributor and:
a) OMG HOLY CRAP i never knew a TJ motor could run so smooth
b) my old distributor had mad crazy play in it apparently and was rusty on the inside, so it was shot
c) no CEL yet and I'm past the point I could get to before.

The engine is noticeably smoother, running at lower RPM's when at speed, and I've found power I didn't know I was missing. I've still got some miles to put on it before i can get emissions and before I can really be sure the stupid CEL is behind me but at the moment it seems to have made a world of difference. Although, it pisses me off that the shop that did the rebuild didn't notice it was rusty or had play in it. Seems like something you'd want to replace when doing a rebuild on a vehicle that's close to 200k miles. On the upshot, now i know how to replace a distributor.