few minor issues I need help with

[Blackout51]

I have a 1998 explorer sport 4.0 sohc 4wd, I just did a minor upper engine refresh (changed out leaking valve cover gasket, upper intake manifold gaskets, cleaned butterfly valve in upper intake manifold, cleaned throttle body, new thermostat and housing, new water pump). Now I have two CEL codes and theres a weird noise coming from behind the passenger air bag, first of all the CELs are one for the air pump thing that sits on top of the intake manifold that helps control the idle, so when I have it in park idling it idles around 1400 rpm, the sensor/pump is new and clean so I don't know what could be the issue there, would adjusting the idle screw help? the second CEL is an emissions code that I did some digging and found the others got this code when there was a leak in the fuel system somewhere, I did notice when I filled the explorer up last time when it was about to click off some fuel shot out underneath between the tank and the filler hole, could this be a cracked fuel filler pipe? it was definitely up in the metal part where the fuel shot out not the lower rubber part. Now the noise isn't so much a problem as a slight annoyance, every time I start the explorer up theres this clicking/tapping noise under the passengers dash that goes away after a few seconds, it sounds kind of like a bad bearing on the blower motor but the fan isn't on when it happens and when I turn the fan on theres no noise. Sorry for the essay here but any ideas/thoughts on these are appreciated!

 

[rb142]

Please DO NOT touch the "idle screw" -- it is not an idle screw. You cannot adjust the idle that way and will only screw things up by doing so.

You most likely have an air leak somewhere which is screwing up the idle speed. It's probably also causing a vacuum problem that is messing up the HVAC actuators behind the dash, making the noise you hear.

For the gas leakage issue, get under the car and check around the filler neck tube. They rust through (especially at the end where they connect to the rubber hose) and cause leaks and evap codes. If it is burping and the gas is not going down the filler well, you may have a plugged vent somewhere. Check the vent solenoid and don't overfill.

 

[Blackout51]

Please DO NOT touch the "idle screw" -- it is not an idle screw. You cannot adjust the idle that way and will only screw things up by doing so.

You most likely have an air leak somewhere which is screwing up the idle speed. It's probably also causing a vacuum problem that is messing up the HVAC actuators behind the dash, making the noise you hear.

For the gas leakage issue, get under the car and check around the filler neck tube. They rust through (especially at the end where they connect to the rubber hose) and cause leaks and evap codes. If it is burping and the gas is not going down the filler well, you may have a plugged vent somewhere. Check the vent solenoid and don't overfill.

I was looking at the gaskets on that new sensor/air pump in top of the manifold and the butterfly valve and they both looked pretty old and worn, all vacuum hoses were hooked up and seemed fine, plus there was no issue before I dug into the motor, those gaskets were going to be my next swap since theyre pretty easy and looked like they were done, however there was also this small greenish color plastic tube that ran down the front passenger side of the engine bay that was a vacuum line to something that got split in half im thinking by age and I tried to tape it together best I could.

The gas leak wasn't a bubble, more like it filled up full and hit a spot in the tube that was leaking, I will get under it tomorrow and try and look for the hole/crack, is the filler tube an easy replace?

 

[rb142]

The filler tube is easy to replace (a few screws at the top and a hose clamp at the bottom), but they aren't cheap to buy. Try somewhere like LMC truck or Rock Auto. If you get a used one it will probably be as rotted as the one you are replacing.

 

[Blackout51]

something I forgot to mention too, when I replaced the thermostat housing I pulled one of the sensors from the old housing which was working just fine and put it in the new housing nd when I tried to do the same with the second old sensor it was all locked up in the old housing so I got a new sensor, now I have one new sensor and one old one and the motor runs good and smooth and the temp reads good on my scan tool but the dash gauge does not work now, is this related to the high idle?

 

[rb142]

One feeds the gauge and the other feeds coolant temp to the PCM. A bad ECT value could make it idle high, but if that one reads good on your scan tool it shouldn't be the problem.

 

[koda2000]

the "air pump" thing is called your IAC (idle air control valve). it sounds like you might have gotten a bad one, or like rb142 said, you have an air leak). i just replaced the IAC on one of my Mountaineers because it was idling up around 1400 rpm. what are the other codes you received? P0171/P0174?

i have used that screw on the throttle body to slightly raise the idle on my '97 SOHC, but it is not and idle adjustment. its purpose is to keep the throttle plate from sticking closed. leave it alone.

as far as you gas leak, your filler pipe is probably rotted. i see good used OE ones for sale on ebay for around $60. or you can by new for $80-$100. personally, i'd rather buy the used OE one.

BTW, almost all CEL codes are emissions related.

 

[Blackout51]

the "air pump" thing is called your IAC (idle air control valve). it sounds like you might have gotten a bad one, or like rb142 said, you have an air leak). i just replaced the IAC on one of my Mountaineers because it was idling up around 1400 rpm. what are the other codes you received? P0171/P0174?

I wish I wrote down the idle code but the emissions code was p0455, and I know the iacv is newer but the guy I bought it from actually replaced it (he's a friend of mine), I was reading that after you clean the valve and the Burtterfly valve underneath of the iacv that you should disconnect the battery to reset the idle which I did and it works but only for a little bit
i have used that screw on the throttle body to slightly raise the idle on my '97 SOHC, but it is not and idle adjustment. its purpose is to keep the throttle plate from sticking closed. leave it alone.

as far as you gas leak, your filler pipe is probably rotted. i see good used OE ones for sale on ebay for around $60. or you can by new for $80-$100. personally, i'd rather buy the used OE one.

BTW, almost all CEL codes are emissions related.

 

[koda2000]

P0455 = "Evaporation System Malfunction, Gross Leak" that sounds like you did not reconnect all the vacuum hoses, particularly the one coming from your fuel tank. that would explain your fast idle. i suggest you recheck your work.

 

[Blackout51]

P0455 = "Evaporation System Malfunction, Gross Leak" that sounds like you did not reconnect all the vacuum hoses, particularly the one coming from your fuel tank. that would explain your fast idle. i suggest you recheck your work.

Which one comes from the fuel tank?

 

[koda2000]

there's a hose that goes from fuel tank to the evap canister located over the spare tire. from there a line runs to the front of the truck to the evap solenoid, which is located under the battery. then a hose runs up to the intake manifold, i believe on the driver's side of the engine. i don't know exactly where on the manifold it connects, but it requires a good vacuum source to work.