Code 0171 lets figure this out.

Okay everyone on my 96 XJ 4.0L 2wd aw4 135,000 miles it has this bizzar problem of running great and then just dieing. I figured at first it was the fuel filter because it really seemed as if the engine was starving for fuel. I put a new filter on and it seemed to work fine for about a week and then starting acting up again. Let me give you a little history about this rig it sat for 2 years because the previous owner was convinced it was FUBAR and all it needed was a cps and water pump so i got it for like 200$.

Could this 0171 code be because the engine is not receiving enough fuel? I'm wondering if I should drop the tank get a new fuel pump and clean the tank out. Let me know what I should be hunting for here.

P0171 is for a "lean" fuel condition.

If this were my vehicle, I would do some testing right out of the gate. Good data = good decisions.

Get a fuel pressure gauge (they can be rented from many big parts stores). Install it on the schrader valve on the fuel rail. Compare your readings to factory spec.

You need to rule proper fuel delivery in or out early in the troubleshooting process, and the fuel pressure test is the best indicator of that.

Thanks, that's something I was gonna plan to check wednesday when I have time. When I researched code 0171 it seemed to be a tricky one to figure out.

P0171 is A**UMING a lean condition because of an abnormally high "RICH" correction factor by the PCM.

So, one or more sensors is telling the PCM the engine is too lean, the PCM is increasing the duration of the injector pulse so much trying to correct the lean it is way out of set parameters, therefore the code.

Test your way out of this. Potential sensors would be the MAT, MAP, o2, possibly the CTS (low on the list). Also, an intake leak UPSTREAM of the o2 sensor will cause the PCM to enrich the mixture, so check the intake manifold mounting/gasket, the vacuum lines, possible injector seals leaking, the throttle body gasket, cracked exhaust header.

Good luck.

So I was convinced it was the fuel delivery, because i pulled out the 2 week old filter and orange sludge came out of it, so i went ahead and ordered a new pump and tank. This rig sat for nearly 2 years before i ought it for 200$ because of a bad cps :-D

After noticing all the orange again after only 2 weeks I knew something was up so I pulled the tank out. When I got a flash light in there it looked like a rotting ship at the bottom of the ocean.

Rock auto had the tank for 112$ shipped so I'll report back if this was the fix for this code.

So a new Pump, strainer, tank, and fuel filter solved this mess. got everything on rock auto for less than 170

I would suggest a treatment with BG44K to flush out the rest of the fuel system all the way through the injectors.

Good luck.

I ran some of the chevron fuel system cleaner through it. Maybe ill order a few of those online for both jeeps. You swear by this stuff?

ktwalker01 said:

I ran some of the chevron fuel system cleaner through it. Maybe ill order a few of those online for both jeeps. You swear by this stuff?

Click to expand...

I like both Techron and BG44K for cleaning fuel system.

For engines that are problematic/symptomatic and a fuel system issue is suspected, I go with BG44K. It really is amazing, although a bit spendy.

For "maintenance" of the fuel system and to keep the fuel system and injectors clean, TECHRON is a good product. Go with the concentrate product though. Just bought some at Wally World for $6.47 which treats 15-20 gallons (pour into 10-15 gallons for best concentration).

ktwalker01 said:

I ran some of the chevron fuel system cleaner through it. Maybe ill order a few of those online for both jeeps. You swear by this stuff?

Click to expand...

Been using BG products since the early 80s in personal and customer's vehicles.

excellent thanks, I saw it was a little pricey. Ill order some to get the rest of the gunk out of the lines and injectors