Help quick!! Will start...won't Idle!

[Jaytee]

I was doing simple maintaince on my 92 4.0. I was recharging my K&N filter and when I put it all back together, it wouldn't run. It will start and jump to about 3000 RPM but then dies. I took it back apart..check all my connections including my sensors and tried again. Samething happened again. I opened up the throdle body and white smoke came out. Anybody have any idea whats wrong???

Thanks in advance,
JT

 

[Ru Dawg]

I've yet to use K&N yet, but maybe you used to much oil recharging the filter? Did ya clean the filter first...maybe the filter isn't dry enough???? I really don't know..just brainstorming!!! It definetly sounds like you are not getting enough air and something like oil or h2o is getting in the intake.

 

[Jaytee]

Well I tried w/ and w/o the filter in place and samething happens. I can keep it running but I have to keep my foot on the gas and RPM's at 1500.

 

[SteveVB]

Check and make sure you didnt crack a vac. hose while you were R&R them. Check the connections to TB vac, the Vac hoses to the filter box, and the electrical connectors at the MAF, and the TB basically anything that you touched, or moved while you were doing the filter replacement. It sounds like a vacuum problem.

Very very slight chance its something other than what you worked on, but triple check what you worked on most recent.

 

[Jaytee]

Well I got some codes for someone to interprete!

72 - "Insufficient Mass Air Flow change during Dynamic Response Test"
29 - "No Input from Vehicle Speed Sensor"
67 - "Neutral Drive Switch circuit open"
53 - "Throttle Position Sensor out of Range"

I got it running now but it Idles Higher than normal (1500)
I'm gonna disconnect the TPS to try maybe to reset it??
ANy Suggerstions?

 

[Perry]

I am not sure this will help, but you can try disconnecting the battery and let the computer reset itself. When I installed the KKM filter they said to disconnect the battery so it could reset itself.
Just an idea.

 

[Jaytee]

I disconnected the battery for 15 sec letting the computer reset but samething happened again. I checked and rechecked my connections but all seemed to be fine. I'm leaning toward the throttle body sensor as the problem. Does anyone have any Ideas how to fix it or do I just need to replace it? how much??
Thanks
JT

 

[Perry]

throttle body

I took mine in to a shop and it cost me $70.00 to have them take it apart and clean it. They said there is a little wire like a fishing line that they clean. I don't think I would take it apart, but if it doesn't run you aren't out anything. I guess that wire tells how much air is going in, then the gas is mixed to the air amount.
Good luck.

 

[Jaytee]

Where can I take it to get it clean?
Dealership??

 

[mike91]

It sounds like a vacuum line b/c I had a broken line several months ago and once the truck was started up, it would die quickly unless you kept your foot on the gas. You can also check your air (something or other) sensor located next to the throttle body. If the gasket isn't mating properly, the truck will act up.

 

[PhxExplorer]

Just a thought, but could you have possibly fouled the MAS with oil from the K&N filter? You could just take it out and spray it with carb cleaner and see if it helps any. Good luck and let us know what you figure out.

 

[Jaytee]

So far no luck! I've checked all my hoses for leaks or loose connections but all seem fine. I sprayed the MAS w/ throttle body cleaner but still did not help. I have it running ok but...when I start it up, RPM's jump up to about 2500 and then drop back down to 1000. It will then slowly (after 30sec) rise up to 1500 RPM's for about 15sec, then will choke down and die.! Seems like a sensor problem but I don't wanna go out and buy sensors I don't need. I made an appointment w/ the Dealership and they can fit me in on Wed. If I don't get it fixed before then I'll just have to pay them $64.00 for them to hook up a computer!! Keep the ideas comming....I'll keep trying 'em.

Thanks
JT

 

[Jaytee]

I believe it may be the MAS b/c I got 2 new codes::

157 - "MAS below minimum voltage"
158 - "MAS above maximium voltage"

I see that there are two screw's that hold it down but they are kind of weird. Like a star almost with the center raised so I can't stick a screw driver in to unscrew.
Am I screwed?
How much does a new MAS cost?
Remember I already sprayed it w/ cleaner so its not dirty!
JT

 

[Triton46]

Its not possible to clean the MAF without removing it. Get a star security screw driver from Ford or NAPA if they have it (mine had plain screws). Take the MAF off and you will see two wires (like light bulb filaments). Spray those with carb cleaner and dab the 'filament' part with a q-tip to get all the oil and dirt off. Allow it to dry at least 30 min then reinstall.

 

[Jaytee]

I finally got the MAS off w/ some needle-nose and a small flat head. I cleaned the filaments and put it back together. Still was having the same problem....Then it dawned on me what happened. There is a hose in the back (near the fire wall) on the manifold. I keeps the vacuum in the manifold. Some how it came off. No clue how it came off but it did. I stuck my finger over the hole and presto!! The engine ran perfect. I'm now in the process of finding some plastic tie-downs so this doesn't happen again. I'm just glad I found it before taking it over to the Ford Dealership where they would of charged me $64.00 for nothing!!

JT

 

[Triton46]

Bravo! Been there, done that. And you can bet you won't ever do that again either. I've learned quite a bit from working on mine and from this board.

 

[Perry]

Congrats!!!
At least you might have learned about some new parts on your Explorer. With the new engines it is hard sometimes to tell what makes things act like they do.
Just glad you got it working.