4.0 sohc red hot exhuast wont idle

[Transmarobirdeater]

Im having problems with my 4.0. Im not sure were too post this because it is a completed swap. I have an 04 explorer 4.0 in a 2000 ranger that was origanally a 3.0 flex fuel 5 speed standard. I have 20,000 miles on the swap so far. Its been driving great. I had an issue with the fuel pump relay buzzing on start up. It seems like the light blue and orange wire that is grounded through the PCM to turn the fuel pump relay on is not working properly. I ran a jumper to this wire and grounded it and turned my fuel pump relay on and off a few times just to make sure i was on the right path. Now I have developed a whole new issue. Now the PCM is not grounding that wire at all. I have too stick a jumper wire in the relay box just too get my fuel pump too come on also when i try to start the engine i have too give it gas too keep it running and it runs real rough like its missing and the exhaust gets way too hot after a couple of minutes. As soon as I let off the gas it dies. What the hell did I do what would cause my motor to do this. It was running like a top right before I messed with the fuel pump relay wire. Need help!

 

[Transmarobirdeater]

Just too bring you up too date on what I have tried. The fuel pump relay wire right now Im not concerned about. I want to know whats making my motor run like sh*t. I have unhooked the exhaust with no results. The motor runs like crap with the exhaust hooked up or not. So I have come to the conclusion that a clooged cat is not the problem I unhooked the MAF, that made it run even worse so I dont think its the MAF. What the Hell Happened.

 

[Transmarobirdeater]

From what I have read. The fuel pump relay is controlled by the PCM. When you first turn the key on the PCM grounds the Light Blue and orange wire for a second or 2 too prime the fuel system. When you begin cranking the PCM grounds the Light Blue and orange wire as long as it is recieving a signal from the cam shaft postition sensor. Non of this is taking place right now. When I turn the pump on myself with a jumper I can start it so I dont think its a PATS issue. I believe PATS wont even let the injectors squirt. Im going to get a ton of parts off an 04 ranger this weekend. Im going to get all the sensors I can carry plus another PCM and Keys. Any Ideas from anyone on this.

 

[Earl43P]

In 2000, PATS (also) disables the starter. I know this because I carry an unchipped key for opening the doors and it will not crank the starter with that key.

If you PM me your e-mail address, I will send you a lot of the 2000 EVTM to help you figure out the problem.

 

[Transmarobirdeater]

If im correct the PATS system in the 2000 ranger is in the dash behind the radio and it is responsible for grounding the fuel pump relay. In the 2004 explorer its part of the PCM. So i believe I have 2 passive anti theft systems in my truck. Since the swap my ranger theft light goes crazy because i havent hooked the 04 PCM's anti theft wire too the gauges. The one in the dash is still hooked up never removed it or hacked any wire however it knows its been started and it doesnt like it but it cant do anything about it because it does not control the 04 explorer PCM. I think that what I got going on. If someone knows for sure that the 2000 ranger passive anti theft system is not actually part of the PCM it would be nice to know.

 

[RonD]

Red hot exhaust means engine is running to lean.

Not probably related but I think it's the Crank Position Sensor(CPS/CKP) that is used by the PCM to tell if engine is turning over and it should continue to supply fuel.

If you haven't done this, disconnect the neg. battery terminal for about 5 minutes, that should reset the PCM/EEC, and see if fuel pump relay works as it should.
Often if the PCM has set a code it will continue to disable the fuel pump until reset.
And that could also be part of the PATS.

 

[Transmarobirdeater]

I have reset the PCM several times. I also left it unhooked for a whole day. It still does not want to privide the ground to turn on the fuel pump relay. I know that red hot exhaust can also be caused by unburnt fuel collecting in the cat. When I unplugged the MAF sensor and ran it for a bit thats what happened. It ran rich as hell then the cat started to glow so I shut her down and plugged the MAF back up. With the MAF hooked up it still runs like sh*t and instead of the cat glowing it starts to glow at the Y. Im not real sure if its to lean or too rich since I have to stay on the throttle too keep it running I assume its too rich.

 

[Transmarobirdeater]

Basically when the MAF is plugged in its still runs rich but not as bad as when its unhooked. Im not going to say for sure but Im pretty confident that Im getting way too much fuel for some reason. It could be a damaged MAF or Crankshaft position sensor or I got an Issue with my PCM. I dont know at this point Im going too start throwing parts at it. Im not getting any DTC's either unless I unhook something.

 

[RonD]

Check the fuel regulator, on the fuel rail, it operates by vacuum, pull off the vacuum hose and check it for fuel/fuel smell, if regulators diaphragm is leaking raw fuel gets sucked into the intake.
Also check the return line.
A pressure gauge would be handy.

 

[Transmarobirdeater]

Im under the impression that the 04 4.0 doesnt have a regulator it uses a pressure sensor. It uses a fuel pump driver to regulate fuel pressure. This is were it gets interesting. When i swapped in the 04 4.0 into the 2000 ranger I didnt swap the fuel system. The PCM knows that the fuel pump driver is missing so it goes to a default setting. Its worked pretty good on the return style fuel system. I think my gas mileage suffers though because the PCM does not have control of the FUEL PUMP plus it goes to the default setting. I have put 20,000 miles on it with the fuel pump driver mode disabled. I just replaced my pump and I can hear it run so I know Im getting fuel. By the way Ford was kind enough to leave the shrader valve off the fuel rail in 04 so you have no test port.

 

[Transmarobirdeater]

Just got the PCM out of the 04 ranger and put it in my truck. It fired right up. I still dont know if my PCM is bad or not I guess PATs could of had it locked up and acting funny. I know that It never gave me any codes for the theft system being activated. I really dont know what to make of all of it. Im just glad the truck starts and runs. Thanks for the help just remember if your truck dont want to idle and your exhaust is way too hot dont throw out the possibility of having a bad PCM.

 

[RonD]

Thanks for the update