I should have also had you check the Intake Air Temperature reading. Sorry about that. If it reads really low, relative to the temperature inside the engine compartment, it's defective.

 

Sorry to keep going on and on here. But there are only a few things that can cause the symptoms you're showing here. Forget fuel injectors. That's POSSIBLE, but not likely. A stuck FI would likely cause your fuel trims to be much higher. The ECM knows how much fuel it's putting in, and is doing it on purpose. We know that because your STFT is positive 10, and not zero. The ECM logic thinks the truck needs more fuel.

We don't have MAF sensors, so the truck still runs well, even though it is a little rich. In fact, a 10% positive fuel trim just causes annoying gas fumes and poor fuel economy. But a bad MAP sensor can cause the issue, a Purge valve, an Intake Temp Sensor, a vacuum leak (most likely), and well, that's about it. I've seen this issue before on some car or another, where the Intake Temp was reported at -40 degrees, or some such ridiculous number. Truck ran fine when it as cold...ran like crap when it warmed up. No Check Engine light until it got nice and warm. Then there was no CEL for the temp sensor. It was giving a valid reading (-40 degrees). it was the wrong reading, but the signal to the ECM was still being sent. It caused the ECM to lock the purge valve open (kinda like the choke being stuck closed on an old car.) Eventually, if the issue gets worse, the O2 sensors will throw a Pegged Rich condition code. Meaning that the ECM cannot compensate for the amount of air being sucked into the engine.

 

ok
at 1700 rpm
short 0.0 to -2.3
long steady at 14.0
also did as suggested plugged vacuum going to purge valve
seem to help a little
by the way thanks for all the help
from all of you
we are a mopar family
2004 neon 1998 grand cherokee 2006 charger rt 2016 charger 2018 charger 2017 ram and two 2017 journeys and the old man 1998 ram

 

You have to keep it going for a few minutes, to see if the STFT stays low. The LFTF will catch up as it's a moving average of the STFT values. Let's see where the numbers are, with the gas pedal depressed for a few minutes. Based on the STFT being +7-10 at idle, and -2 with the pedal down, you most certainly have a vacuum leak. Go put some propane, or carb cleaner all around anywhere with a vacuum port. Pay special attention to the Intake Manifold.

 

ok
i will check that out again
as stated in the beginning i could no find a vacuum leak
sprayed carb cleaner all along intake around throttle body base
at booster check valve
ac vac lines , under battery tray cruise servo
and found nothing ,but i will try that again later today
thanks again
mike

 

Don't forget the throttle body. The only other place I can think of that unmetered air can get into the system is the exhaust manifold. That's a long shot, but it's possible.

 

The vacuum leak could be in the cab. The HVAC controls are vacuum operated.

 

Also at the front axle, Xfer case, or somewhere between, if it's a 4X4.