mopar parts
 

Also, the coil and plug wires are mopar performance parts. And the plugs are NGK's.

I don't think having the head gasket changed would affect it, unless perhaps some electrical connector was left undone? Sounds like all of your ignition parts should be fine too. Did you happen to get the CCA's from the battery?

I'm am actually not sure on that one j_son.

From the Service Manual
 

FUEL PRESSURE REGULATOR DESCRIPTION

A combination fuel filter and fuel pressure regulator
is used on all gas powered engines. It is located
on the top of the fuel pump module.
It contains a diaphragm, calibrated springs and a
fuel return valve. The internal fuel filter (Fig. 8) is
also part of the assembly.

OPERATION
Fuel Pressure Regulator Operation: The pressure
regulator is a mechanical device that is calibrated
to maintain fuel system operating pressure of
approximately 400 kPa ±34 kPa (58 psi ±5 psi.) at
the fuel injectors.
Fuel is supplied to the filter/regulator by the electric
fuel pump through an opening tube at the bottom
of filter/regulator (Fig. 8).
The fuel pump module contains a check valve to
maintain some fuel pressure when the engine is not
operating. This will help to start the engine.
If fuel pressure at the pressure regulator exceeds
approximately 58 psi, an internal diaphragm closes
and excess fuel pressure is routed back into the tank
through the pressure regulator. A separate fuel
return line is not used with any gas powered engine.

FUEL INJECTION OPERATION
OPERATION -INJECTION SYSTEM
All engines used in this section have a sequential Multi-Port Electronic Fuel Injection system. The MPI system is computer regulated and provides precise air/fuel ratios for all driving conditions. The Power-train Control Module (PCM) operates the fuel injec*tion system.
The PCM regulates:
•Ignition timing
•Air/fuel ratio
•Emission control devices
•Cooling fan
•Charging system
•Idle speed
•Vehicle speed control

Various sensors provide the inputs necessary for the PCM to correctly operate these systems. In addi*tion to the sensors, various switches also provide inputs to the PCM.
The PCM can adapt its programming to meet changing operating conditions.
Fuel is injected into the intake port above the intake valve in precise metered amounts through electrically operated injectors. The PCM fires the injectors in a specific sequence. Under most operat*ing conditions, the PCM maintains an air fuel ratio of 14.7 parts air to 1 part fuel by constantly adjust*ing injector pulse width. Injector pulse width is the length of time the injector is open.
The PCM adjusts injector pulse width by opening and closing the ground path to the injector. Engine RPM (speed) and manifold absolute pressure (air density) are the primary inputs that determine injector pulse width.
OPERATION -MODES OF OPERATION
As input signals to the PCM change, the PCM adjusts its response to output devices. For example, the PCM must calculate a different injector pulse width and ignition timing for idle than it does for Wide Open Throttle (WOT). There are several differ*ent modes of operation that determine how the PCM responds to the various input signals.
There are two different areas of operation, OPEN LOOP and CLOSED LOOP.
REMOVAL-2.4LSRT-4 .................50
INSTALLATION
INSTALLATION .......................50
INSTALLATION-2.4LSRT-4 .............50
During OPEN LOOP modes the PCM receives input signals and responds according to preset PCM programming. Inputs from the upstream and down*stream heated oxygen sensors are not monitored dur*ing OPEN LOOP modes, except for heated oxygen sensor diagnostics (they are checked for shorted con*ditions at all times).
During CLOSED LOOP modes the PCM monitors the inputs from the upstream and downstream heated oxygen sensors. The upstream heated oxygen sensor input tells the PCM if the calculated injector pulse width resulted in the ideal air-fuel ratio of 14.7 to one. By monitoring the exhaust oxygen content through the upstream heated oxygen sensor, the PCM can fine tune injector pulse width. Fine tuning injector pulse width allows the PCM to achieve opti*mum fuel economy combined with low emissions.
For the PCM to enter CLOSED LOOP operation, the following must occur:
(1) Engine coolant temperature must be over 35°F.
•If the coolant is over 35°F the PCM will wait 38 seconds.
•If the coolant is over 50°F the PCM will wait 15 seconds.
•If the coolant is over 167°F the PCM will wait 3 seconds.

(2) For other temperatures the PCM will interpo*late the correct waiting time.
(3) O2 sensor must read either greater than 0.745 volts or less than 0.29 volt.
(4) The multi-port fuel injection systems has the following modes of operation:
•Ignition switch ON (Zero RPM)
•Engine start-up
•Engine warm-up
•Cruise
•Idle
•Acceleration
•Deceleration
•Wide Open Throttle
•Ignition switch OFF
•(5) The engine start-up (crank), engine warm-up, deceleration with fuel shutoff and wide open throttle modes are OPEN LOOP modes. Under most operat*ing conditions, the acceleration, deceleration (with A/C on), idle and cruise modes, with the engine at operating temperature are CLOSED LOOP modes.



FUEL INJECTION (Continued)
IGNITION SWITCH ON (ZERO RPM) MODE
When the ignition switch activates the fuel injec*tion system, the following actions occur:
•The PCM monitors the engine coolant tempera*ture sensor and throttle position sensor input. The PCM determines basic fuel injector pulse width from this input.
•The PCM determines atmospheric air pressure from the MAP sensor input to modify injector pulse width.

When the key is in the ON position and the engine is not running (zero rpm), the Auto Shutdown (ASD) and fuel pump relays de-energize after approximately 1 second. Therefore, battery voltage is not supplied to the fuel pump, ignition coil, fuel injectors and heated oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in park or neutral (automatic transaxles) or the clutch pedal is depressed (manual transaxles) the ignition switch energizes the starter relay when the engine is not running. The following actions occur when the starter motor is engaged.
•If the PCM receives the camshaft position sensor and crankshaft position sensor signals, it energizes the Auto Shutdown (ASD) relay and fuel pump relay. If the PCM does not receive both signals within approximately one second, it will not energize the ASD relay and fuel pump relay. The ASD and fuel pump relays supply battery voltage to the fuel pump, fuel injectors, ignition coil, (EGR solenoid and PCV heater if equipped) and heated oxygen sensors.
•The PCM energizes the injectors (on the 69° degree falling edge) for a calculated pulse width until it determines crankshaft position from the camshaft position sensor and crankshaft position sensor sig*nals. The PCM determines crankshaft position within 1 engine revolution.
•After determining crankshaft position, the PCM begins energizing the injectors in sequence. It adjusts injector pulse width and controls injector synchroni*zation by turning the individual ground paths to the injectors On and Off.
•When the engine idles within ±64 RPM of its target RPM, the PCM compares current MAP sensor value with the atmospheric pressure value received during the Ignition Switch On (zero RPM) mode.

Once the ASD and fuel pump relays have been energized, the PCM determines injector pulse width based on the following:
•MAP
•Engine RPM
•Battery voltage
•Engine coolant temperature
•Inlet/Intake air temperature (IAT)

• Throttle position
• The number of engine revolutions since cranking was initiated
During Start-up the PCM maintains ignition tim*ing at 9° BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs are received by the PCM:
•Manifold Absolute Pressure (MAP)
•Crankshaft position (engine speed)
•Engine coolant temperature
•Inlet/Intake air temperature (IAT)
•Camshaft position
•Knock sensor
•Throttle position
•A/C switch status
•Battery voltage
•Vehicle speed
•Speed control
•O2 sensors

The PCM adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle speed. Engine idle speed is adjusted through the idle air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this is a CLOSED LOOP mode. During cruising or idle the following inputs are received by the PCM:
•Manifold absolute pressure
•Crankshaft position (engine speed)
•Inlet/Intake air temperature
•Engine coolant temperature
•Camshaft position
•Knock sensor
•Throttle position
•Exhaust gas oxygen content (O2 sensors)
•A/C switch status
•Battery voltage
•Vehicle speed

The PCM adjusts injector pulse width and controls injector synchronization by turning the individual ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition timing. The PCM adjusts the air/fuel ratio according to the oxygen content in the exhaust gas (measured by the upstream and downstream heated oxygen sen*sor).
The PCM monitors for engine misfire. During active misfire and depending on the severity, the PCM either continuously illuminates or flashes the malfunction indicator lamp (Check Engine light on


FUEL INJECTION (Continued)
instrument panel). Also, the PCM stores an engine misfire DTC in memory, if 2nd trip with fault.
The PCM performs several diagnostic routines. They include:
• Oxygen sensor monitor
• Downstream heated oxygen sensor diagnostics during open loop operation (except for shorted)
•Fuel system monitor
•EGR monitor (if equipped)
•Purge system monitor
•Catalyst efficiency monitor
•All inputs monitored for proper voltage range, rationality.
•All monitored components (refer to the Emission section for On-Board Diagnostics).

The PCM compares the upstream and downstream heated oxygen sensor inputs to measure catalytic convertor efficiency. If the catalyst efficiency drops below the minimum acceptable percentage, the PCM stores a diagnostic trouble code in memory, after 2 trips.
During certain idle conditions, the PCM may enter a variable idle speed strategy. During variable idle speed strategy the PCM adjusts engine speed based on the following inputs.
•A/C status
•Battery voltage

• Battery temperature or Calculated Battery Tem*perature
•Engine coolant temperature
•Engine run time
•Inlet/Intake air temperature
•Vehicle mileage

ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog*nizes an abrupt increase in Throttle Position sensor output voltage or MAP sensor output voltage as a demand for increased engine output and vehicle acceleration. The PCM increases injector pulse width in response to increased fuel demand.
• Wide Open Throttle-open loop
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera*tion the following inputs are received by the PCM:
•A/C status
•Battery voltage
•Inlet/Intake air temperature
•Engine coolant temperature
•Crankshaft position (engine speed)

• Exhaust gas oxygen content (upstream heated oxygen sensor)
•Knock sensor
•Manifold absolute pressure
•Throttle position sensor

• IAC motor (solenoid) control changes in response to MAP sensor feedback
The PCM may receive a closed throttle input from the Throttle Position Sensor (TPS) when it senses an abrupt decrease in manifold pressure. This indicates a hard deceleration (Open Loop). In response, the PCM may momentarily turn off the injectors. This helps improve fuel economy, emissions and engine braking.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open*throttle operation, the following inputs are used by the PCM:
•Inlet/Intake air temperature
•Engine coolant temperature
•Engine speed
•Knock sensor
•Manifold absolute pressure
•Throttle position

When the PCM senses a wide-open-throttle condi*tion through the Throttle Position Sensor (TPS) it de-energizes the A/C compressor clutch relay. This disables the air conditioning system and disables EGR (if equipped).
The PCM adjusts injector pulse width to supply a predetermined amount of additional fuel, based on MAP and RPM.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the OFF position, the following occurs:
•All outputs are turned off, unless 02 Heater Monitor test is being run. Refer to the Emission sec*tion for On-Board Diagnostics.
•No inputs are monitored except for the heated oxygen sensors. The PCM monitors the heating ele*ments in the oxygen sensors and then shuts down.

One other thing you may try if you have an OBDII Scan Tool, is to crank the engine 3 times for 15 seconds to allow and DTCs get into the computer and then check for any codes. Having any DTCs helps narrow the problem down. Remember, the Check Engine Light doesn't have to be on to have codes in the computer.

Wow!
 

Wow, darthroush, your my new best friend! The info you gave me was above and beyond! Thanks so much! Although it will take me some time to go through everything, this morning I made a new discovery leaning my decision more toward changing the fuel pump and filter assembly(if you guys approve). Anyway, this morning for some reason I decided to try and prime the fuel pump about 5 times before starting the car, and guess what? It fired right up! I was happy as hell because I live in St. Louis and its been real cold here, and like I've said before when its under 40 degrees is the only time I have these problems. CCA's read about 580, so I think that should be fine. Let me know what you guys think about whats going on with me priming the fuel pump and it working. Again, thanks alot.:)

Lets see here
 

I think I figured out the profile signiture thing, I'm gonna give it a try and see if my pic comes up with this reply. Hope it works.? Man, I have some learning to do with this online forum stuff. lol.:confused:

Nope
 

Damn, still no picture. Guess I'll have to try again.:confused:

Last time
 

Ok, last time with this signature and picture thing, if this dosen't work I give up. lol. Here goes nothin.:D

You may try replacing the fuel filter first and see how that works (plus the filter and the tool isn't that expensive. Not sure how many miles are on your car, but a dirty filter can cause problems. Worst case, sounds like you may have narrowed it down and need a pump. I'd try it again at least a few more times and see what happens though to make sure it wasn't a fluke. CCA's are good.

BTW, your signature works. :)