[wortner]

Hi All,

Truck: 2003 lb7 4x4 105000 mi, stock

Finished buttoning up my injectors last night, started it up and idle's rougher than a rabid ape in an oil drum. I read a few threads where guys had this problem, and said it came out of it, just had to get the air out of the system. I started and stopped it, primmed again, started and stopped, probably 15+ times, as well as let it run for a while. It pulls out of idle and smooths out by 1000 rpm and runs fine, but just can't idle.

It throws a p0193 (fuel rail pressure sensor circuit high input). The only other thing I just though of is that I hadn't hooked up the maf (?) sensor on the intake yet, but I don't think that would have much to do with it not idleing.

I checked all connections and fuel line fittings, nothing loose or leaking. It starts every time without a problem, idles nice for 2-3 seconds, then goes into the rough idle (almost feels like its on 4 cylinders)

Thanks guys!

 

[mcle6103]

your maf sensor I think is rather vital to the operation of the vehicle and can cause problems if not plugged in

 

[DuraTitus]

Sounds like a wiring issue.

If an injector wire is grounding out somewhere, or not tightened correctly the FICM will close down the whole circuit, causing the engine to fire on only 4 cylinders.

You can check the injector wires coming out of the valve covers with a ohm meter, and see if you can locate a problem.

Hooking up the MAF might solve the issue as well.

The weird thing is that it smooths out at 1,000 RPM.

Does it have an engine light come on, and if so, what are the engine codes?

 

[wortner]

Thanks guys.....got it figured out. The code was p0193, which is a high fuel rail sensor input.....well, I triple checked all my connections after work yesterday, and when I wiggled the connector, it popped out, guess the tab didn't catch on the sensor. Started up and runs beautifully now!

Just an FYI, with the MAF sensor unhooked, the truck runs underpowered, have no problem getting to hwy speeds, but have no umph behind it. When the MAF sensor was unplugged, it threw p0102 and p0113, which relate low input in MAF and high input for intake air temp.

End of story is she runs fine, no more white haze, and no more caughing in idle. :drink

 

[mcle6103]

Right on