01 4.6 stalling

[Pclaythomas]

Hi guys,
I really need some help. I have an 01 Expedition with the 4.6.
I have replaced the tps, plugs, coils, fuel filter, mass air sensor, and added a cold air intake.
All this in an attempt to correct a stall that happens after the vehicle has been driven a while.
Also, the "service engine light" is on...again. I went to Autozone and they said it was a bad fuel cap. So, I replaced that.
Anyway, the motor stalls anytime I let off and then easily accelerate. Also, while the cruise is on.
Any ideas?

 

[Bedrck47]

Post the codes that Autozone read.

How many miles on the expy.

Have you ever cleaned the exhaust ports thru the throttle body This requires that the throttle body be removed from the intake There is a good video on you tube about this

 

[Pclaythomas]

I have cleaned the egr,the throttle body and upper intake. The code is P0442. Fuel cap replacement. But, I did that,too. I did notice when I attempt to fill it up, I smell fuel and it looks like the rubber fuel elbow going into the tank is leaking. Could this be the cause of the code? Also, I can't fill it completely and the guage only registers it being 3/4.
Also, it has 195,000.

 

[Bedrck47]

P0442 - EVAP Control System Leak Detected (Small Leak) The PCM monitors the complete EVAP control system for presence of a small fuel vapor leak. The system failure occurs when a fuel vapor leak from an opening as small as 1.016 mm (0.04 inch) is detected by the EVAP running loss monitor test.

• After-market EVAP hardware (such as fuel filler cap) non-conforming to required specifications
• Small holes or cuts in fuel vapor hoses/tubes
• Canister vent solenoid stays partially open on closed command
• Damaged, cross-threaded or loosely installed fuel filler cap
• Loose fuel vapor hose/tube connections to EVAP system components
• EVAP system component seals leaking (EVAP canister purge valve, fuel tank pressure sensor, canister vent solenoid, fuel vapor control valve tube assembly or fuel vapor vent valve assembly)

 

[Pclaythomas]

So, can this cause the stalling issue?
After it warms up, the stalling occurs more often.

 

[1955moose]

Any leaking hose, can and will cause a driveability issue. Basically our suvs are a sealed system, sort of like our body. Could you imagine trying to walk around with a deep cut in your arm or leg, with blood coming out. You wouldn't last long. Hoses that are designed to be sealed tight, then develop cracks and tears, are letting out the vacuum, or fumes that are supposed to be kept in. Have your system smoke checked. That's usually the fastest/easiest way to find bad hoses.

Sent from my N9131 using Tapatalk

 

[toomanytoys]

I don't see anything about iac. Was it swapped or reset?

 

[Pclaythomas]

,I just cleaned it. Replace?

 

[toomanytoys]

When you cleaned it, did you unplug and remove it? If so you need to reset it

 

[Pclaythomas]

Yes, I completely removed it. How do I reset it?

 

[toomanytoys]

Run the truck till warm and then in plug the iac. You will then need to adjust the idle screw until the truck idles properly. Once the truck is idling correct plug the iac back in. The idle should jump for a second or two and then settle back down.

I also see that you replaced your tps? Did you set the voltage?

 

[Pclaythomas]

No,Ijust plugged it in and reconnected the battery.

 

[toomanytoys]

If you removed the tps it must be set. Voltage must be at .90-.95 with key on engine off

 

[Pclaythomas]

Ok. How do I do that?

 

[toomanytoys]

Loosen the two screws a little so the tps can swivel. Then you must read the voltage in the circuit. I usually pierce the wire with a small safety pin. There are three wires- ground, circuit power and sensor output. If you see 5 volts or more than you tapped the power circuit. If you see nothing that's the ground. You need the circuit output. Once you have tapped it turn the key to the run position but don't start the truck. Read the voltage. Adjust by slowly twisting the tps until the volt meter reads .90-.95. Once you get that tighten the screws and you're done

 

[Bedrck47]

Not a good idea to "pierce the wire with a small safety pin"

Now its a place for corrosion to start

 

[toomanytoys]

Never had a problem in the 25+ years that I have owned my cars. And I live on the coast

 

[Bedrck47]

I haven't either. But its not a good idea to poke holes in wires.
But if you do then you should coat them afterwards

And I have owned cars for over 50 years

 

[toomanytoys]

That's not what I meant. I did this on my LX 5.0 back in 91 as part of the "10 minute tune up". 145k miles and 26 years later and still the same car and tps with no problems. Not to mention my two 87GNs

 

[and0r]

P0442 - EVAP Control System Leak Detected (Small Leak) The PCM monitors the complete EVAP control system for presence of a small fuel vapor leak. The system failure occurs when a fuel vapor leak from an opening as small as 1.016 mm (0.04 inch) is detected by the EVAP running loss monitor test.

• After-market EVAP hardware (such as fuel filler cap) non-conforming to required specifications
• Small holes or cuts in fuel vapor hoses/tubes
• Canister vent solenoid stays partially open on closed command
• Damaged, cross-threaded or loosely installed fuel filler cap
• Loose fuel vapor hose/tube connections to EVAP system components
• EVAP system component seals leaking (EVAP canister purge valve, fuel tank pressure sensor, canister vent solenoid, fuel vapor control valve tube assembly or fuel vapor vent valve assembly)

this post is useful