P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input

MAS? ECU? TPS?

 

Yeah, it was because he unplugged the TPS and then started it. The ECU didn't see it and reported it.
Buy a new TPS. That's the only thing that you touched and it resolved your high idle issue. Unless it was knocked out of place, I think it's just really dirty and gets stuck, buy a new one. It doesn't seem like you're going to clean the TB anytime soon [sm=smiley21.gif]

 

now say this is my motor minus the turbo i disconnected the sensor in the circle. i was just trying to get some results, but i am going to clean my tb.

 

well cleaned up the tb today it was dirtier than it looked. checked the voltage on the TPS and that was normal. so I dont know what to do, i put some lucas fuel additve in today and filled her up and it seems to be running fine. will keep updated?
anyone have any more thoughts?

 

well its been a couple days now. all in all she feels like she got a bit more pep, my concern is while playing with the throttle cable i noticedit had some slack in it, i know its not major but i could prevent me from being completly WOT. Is there a way to tighten this up i did it to my explorer but i think i need to redo it. i'll check it out. i need to replace my valve cover gasket i think its leaking a bit of oil from there i smelt some burnt oil tonight when i got to work. and my (i think) crank angle sensor had a bit of oil on it.

 

i read on dsmtuners that it could be IAC. how hard is that to test and how do i go about testing that?

 

That sensor is the MAP sensor...funny, I just helped someone with it's location on an Avenger 420a today.


To adjust the cable, you should only move the brass looking bracket that is attached to the intake manifold on the front part of it, just below the EGR tube...make that PCV valve. Referrence that pic above, the strut bar is in front of that cable adjustment bracket.
If your crank angle sensor has oil on it, it may send some erroneous info to the ECU if it has wet oil on it...remember conductivity. Clean it with a degreaser and then contact cleaner. Just leave it in place though. There's no need to remove it. Remove the plug, just not the sensor. Spray into the sensors plug some contact cleaner though.


Idle surge can be caused by the IAC, but that happens most to the 4g63 motors...not saying that it can't with a 420a, it's just not as common. Follow the book on testing it. There's really no shortcuts to it.

 

thanks coupe. i cant find it in my chilton book(iac)

 

Idle surge and what can cause it...
- The coolant temp sensor can also give the ECU erroneous info by telling it that the coolant is still cold and in turn your motor will get more fuel. I don't remember the 6g73 having one or two (the 420a is setup almost identical). The 4g63 has two, one for the gauge (one wire) and another for the ECU (two wire). If you have one with two wires, that's the one to change.
- The IAC/ISC will cause it too.
- The Manifold Absolute Pressure can also.
- EGR can. Emission tract
- Vacuum leaks can.
- Low battery can, but not severe and you'll also notice dimming lights at idle as the fans, A/C kick in.
- Bad o2 can. It will send erroneous info to the ECU about closed loop fuel map.
- TPS can.
- Any air leak from the intake tract will cause idle surge.
That's all I can think of off the top of my head.
Most of those above won't idle a motor to 4k on it's own. It takes a combination of them to do that.


*edited out "coolant temp switch" since it's the same as the coolant temp sensor. The only difference is one talks to the ECU (switch/sensor) and the other talks to the gauge (sensor). Both are called the same thing at times. I edited to keep confusion down"

 

that makes me want to cry.. reading it could be a combo. cool well at least i have some things to check.
tps check. the voltage was normal at idle. when we went to wot the volts went down. Normal?