[oldmarine]

The intake manifold can get a little oily inside because the PCV system pulls oil fumes into the intake manifold. It shouldn't affect the performance of the MAP sensor.

One thing I did notice on your photo of the MAP sensor connector, is that it is gray. The throttle position sensor (TPS) on the throttle body has a very similar connector, same basic shape and three wires. According to the FSM, the connector on the TPS is gray, and the connector on the MAP sensor is black. Is the connector on your TPS black? Is the wiring long enough on both connectors to reach the other sensor? I'm thinking they may be swapped, which would really confuse the PCM.

 

[Branden.d]

The intake manifold can get a little oily inside because the PCV system pulls oil fumes into the intake manifold. It shouldn't affect the performance of the MAP sensor.

One thing I did notice on your photo of the MAP sensor connector, is that it is gray. The throttle position sensor (TPS) on the throttle body has a very similar connector, same basic shape and three wires. According to the FSM, the connector on the TPS is gray, and the connector on the MAP sensor is black. Is the connector on your TPS black? Is the wiring long enough on both connectors to reach the other sensor? I'm thinking they may be swapped, which would really confuse the PCM.

 

[Branden.d]

No its also grey and it's tied into all the connections on this side of the engine bay. Near the brake booster kinda. Won't reach to front of engine

 

[Branden.d]

From the FSM for the 4.7L engine:
The MAP sensor is located on the front of the intake manifold. An o-ring seals the sensor to the intake manifold.

Also from the FSM:
The MAP sensor is used as an input to the Powertrain Control Module (PCM). . . The MAP sensor input is the number one contributor to fuel injector pulse width.

Could a valve cover leak be causing the issues now then? Because I noticed that there was smoke from under the airbox and I also noticed some wetness on the valve cover area but didn't think much of it untill i was having a friend look at it and we noticed smoke coming from the passenger side under the airbox so I think the valve cover gasket maybe the culprit for some of the map readings being off. What do you think?

 

[oldmarine]

A valve cover gasket leaking badly may be the source of the smoke as oil drips on to the exhaust manifold, but it will not affect the MAP readings. Oil leaking out of the valve covers means the PCV system is not even creating enough vacuum to keep the oil from leaking out, so it would not affect the intake manifold vacuum.

As you have already changed the MAP sensor and are still getting bad readings, I suggest you check your 5 volt system used for many of the sensors. If you have a DVM, check your MAP connector as follows: check pin #1 (on the left in your picture) that it has a red wire coming in to the pin, and the voltage at the pin with the key on of 5 volts. Then check pin #2 for a black wire with light blue trace coming in to the pin, and that the pin is grounded.

If you're not getting 5 volts at pin #1, or if pin #2 is not grounded, check the connector for the throttle position sensor (TPS). It's on the throttle body, and the connector is very similar to the MAP sensor connector. On the TPS connector, check that a red wire is coming to pin #1, and that you're getting 5 volts at that pin with the key on. Then check that pin #3 has a black wire with a light blue trace, and that it is grounded.

If you're getting 5 volts at the TPS but not at the MAP sensor, check wiring and connector for the MAP sensor. If you're not getting 5 volts at either connector, check the pins at the PCM. Both the MAP sensor and the TPS are powered (5 volts) from the same wire on the PCM, and both sensors are grounded from the same wire on the PCM. (5 volt power, connector 1, pin #17 on PCM, sensor ground, connector 1, pin #4)

If you don't feel comfortable doing these checks, see if you have a friend who has experience, or invest in the services of a professional mechanic. Be very careful when doing these checks with the key on. Make sure you are contacting only the pins, and only with a DVM (i.e., don't use a test light connected to the battery). Excessive voltage or shorting may damage the PCM.

 

[Branden.d]

A valve cover gasket leaking badly may be the source of the smoke as oil drips on to the exhaust manifold, but it will not affect the MAP readings. Oil leaking out of the valve covers means the PCV system is not even creating enough vacuum to keep the oil from leaking out, so it would not affect the intake manifold vacuum.

As you have already changed the MAP sensor and are still getting bad readings, I suggest you check your 5 volt system used for many of the sensors. If you have a DVM, check your MAP connector as follows: check pin #1 (on the left in your picture) that it has a red wire coming in to the pin, and the voltage at the pin with the key on of 5 volts. Then check pin #2 for a black wire with light blue trace coming in to the pin, and that the pin is grounded.

If you're not getting 5 volts at pin #1, or if pin #2 is not grounded, check the connector for the throttle position sensor (TPS). It's on the throttle body, and the connector is very similar to the MAP sensor connector. On the TPS connector, check that a red wire is coming to pin #1, and that you're getting 5 volts at that pin with the key on. Then check that pin #3 has a black wire with a light blue trace, and that it is grounded.

If you're getting 5 volts at the TPS but not at the MAP sensor, check wiring and connector for the MAP sensor. If you're not getting 5 volts at either connector, check the pins at the PCM. Both the MAP sensor and the TPS are powered (5 volts) from the same wire on the PCM, and both sensors are grounded from the same wire on the PCM. (5 volt power, connector 1, pin #17 on PCM, sensor ground, connector 1, pin #4)

If you don't feel comfortable doing these checks, see if you have a friend who has experience, or invest in the services of a professional mechanic. Be very careful when doing these checks with the key on. Make sure you are contacting only the pins, and only with a DVM (i.e., don't use a test light connected to the battery). Excessive voltage or shorting may damage the PCM.

Hey so is it possible that I have the purge valve houses hooked up incorrecly? I mean I don't thing it's possible but I don't quite remeber if I removed both hoses at the same time and then forgot which one went on top and which on bottom..

It may have happened like that last time I was going down the rabbit hole looking for a soultion to the codes truck was throwing/(small evap leak.)

 

[immattj]

Hey so is it possible that I have the purge valve houses hooked up incorrecly? I mean I don't thing it's possible but I don't quite remeber if I removed both hoses at the same time and then forgot which one went on top and which on bottom..

It may have happened like that last time I was going down the rabbit hole looking for a soultion to the codes truck was throwing/(small evap leak.)

I seem to remember a post in which OldMarine said that his purge solenoid had one of the ports that was labeled "vac." You might check & see if you can see that on yours.

 

[oldmarine]

On RockAuto, the purge solenoid for the 4.7L is different than the one for the 3.9L. But looking at the pictures of the ones available, you can see that the port furthest from the electrical connector is labeled CAN, which should be where the hose from the canister would connect. The other port should be for the vacuum line going to the intake manifold or throttle body would connect.

 

[Branden.d]

Yes I did notice the CAN indication had no clue what that meant but I'll go see if I have it correct.