Fuel issues

[humvee]

Hi guys, wondering if anyone can help me diagnose this fuel problem.

Symptoms: Rough idle / stops accelerating and backfires frequently
I've been driving it like this for 2 weeks, it only stalled once, but the above symptoms are always there.

Pulling these codes:
P0193 - Fuel Rail Pressure Sensor Circuit High Input
P2635 - Fuel pump low flow / performance (BUT fuel pressure is 95psi, double the usual)
P069E - malfunction with the fuel pump control module

I don't understand how the fuel system can be running lean, while the fuel pressure is double its usual psi.
Do I have a bad fuel sensor? Fuel system control module? Or a pump that over performs when its dying?

Anyone had this happen to them?

 

[humvee]

bump

 

[Jeepwalker]

You're right, it doesn't make sense. I am always leery of codes. I can't count the number of times I've had simple things in the many years of doing this that spoofed unrelated codes and had me chasing dead-ends ...only to end up being something simple and basic. More often than not problems end up being simple things.

That's why on the troubleshooting tree, the first thing the OEM manuals say to do is perform basic inspections which typically include spark, fuel pressure, vacuum leaks and vac reading, hoses grounds, etc. Even if you watch ScannerDan's videos, he (the Snap-on expert and scanner trainer) had one particular video where he chased all sort of dead ends on a particular vehicle, replaced a few sensors the scanner indicated was bad ....only to find out several hours later the poor idle was caused by a bad engine ground!!

So, going back to basics, if you haven't done so, thoroughly check over all your vacuum hoses to make sure there isn't a cracked one, or intake bolts haven't vibrated loose? Spray some carb cleaner around (or an unlit propane tank with a hose on the end) to see if it smooths out in any particular area. If you have a vac gauge, hook it up ad read measurements, look for a steady reading. Also, I would thoroughly inspect the PCV system and any and all joints/pipes, etc. On my last Jeep I had several un-related codes that were caused by a cracked rubber (brittle) elbow at the PCV. Then inspect the plugs for cracked insulators ....OHM out the coils. Check grounds. Clean the MAF sensor. Any of those items could potentially cause the symptoms you're experiencing.