RUNNING RICH.....AGAIN

[redthunder]

just a little background info-
94 Limited-running rich a couple months ago and replaced:
FPR
MAF
O2 Sensors
tightened intake bolts, tryed to replace fuel filter (couldn't get front side apart). Checked fuel pressure, it was ok, with no leakdown. Put a new computer in, ran perfect till now.

Now- running real rich and the thing doesn't shift into OD, no matter how fast I go. Decided to buy the code scanner from Autozone because I am realizing Explorer's are POS. Came up with codes of 57 & 58. Little book that came w/ the scanner says that code 57 is Neutral Pressure Switch or Circuit failed in Nuetral Position or Octane adjust service pin installed. Code 58 is Vane Air Temp sensor - volt too high or Crank fuel delay service pin in use or Idle tracking Switch circuit failure.
AGAIN!!!
Anybody's help is greatly appreciated

 

[asp84]

Hmm, I read your previous posts. With a new FPR, MAF, 02 and computer, it seems wierd that your having these problems.
Have you had your Throttle Position sensor VOLTAGE checked? Has anybody tampered with your wiring?

Concerning the Overdrive: The overdrive band is not controlled by the transmission. (controlled by Vaccumm) I think what you are referring to is the Torque Converter "Lockup clutch" function which is controlled by the EEC-IV computer system. Hopefully the transmission is related to an electric problem and not something mechanical.

You might want to try and find a shop that knows there Fords.

Good Luck,
Al

 

[Howard]

As its a 94 just a thought but are you loosing ATF by any chance? Or have you got a vacuum leak some where? Just my 2p worth.

 

[redthunder]

asp84 - I haven't checked the TPS voltage yet. The X always gets garaged @ night.
howard - I have checked the fluid level and it is OVER full. I have never put any additional fluid in. I guess I'll be checking some vac lines this weekend
Thanks for the sugs so far

 

[ammo troop]

try replacing you t-stat, I went through the same problem w/ my 93'. After putting in a new computer and a few other sensors with no luck, a $5 t-stat fixed the problem.

 

[AlaskanJack]

Excuse my ignorance but what is a "T-Stat"?

 

[Jason_25]

Originally posted by AlaskanJack
Excuse my ignorance but what is a "T-Stat"?

Short for thermostat.

 

[fordkrazy]

lesson one in solving richness problems....run code scan with engine running....step two...dont fix the codes you get...just look at the areas its pointing you to...the first codes should be looked at first as they may be causeing the latter codes.....if there is nothing but a sensor related to the code then check the voltage of that sensor to see if its really bad....there might be something mechanical or dirty "upstream" from the sensor that is causeing it to give a bad value.

in my oppinion...listing what you replaced...i would look at the egr valve as its a remote feed back system rather than a pressure feed back system...its located on the drivers side above the exhaust header....if the egr checks out ok then look at its sensor.

also are you sure you have the right computer installed? i dont know how it would run if you didnt but those codes dont sound right...the neutral sensing switch wouldnt make it run rich( it would keep it from starting) and there isnt a octane adjust service pin on the X's to my knowledge...thats an old TFT distributer system thing

 

[Jag]

Check the air charge and water temperature sensors.

 

[410Fortune]

I wouldnt put it pas the new 02 sensors to have failed either, especially if they are Bosch brand.

OHM them out.

Running rich = it will kill your cat and 02's in a hurry

 

[redthunder]

fordkrazy - I can't be positive if it is the correct computer, but, she ran excellent (after the computer was changed) till 1 1/2 wks ago. It is doing the exact same thing it did last time. So, what I'm thinking is, something is killing the computer. I heard there was a check where you remove the computer, hook a tester of some kind to the harness, and it checks the wiring. Anybody heard?

jag - how do I check that?

410 - I thought the Bosch O2's were good? What should they OHM at?


THanks again guys.....

 

[410Fortune]

the Bosch 02's dont seem to work well with the 4.0L.
Stick with OEM, Napa sells them, I cant think of the brandname but it starts with an N.

You will need the service manual or CD for the 02 test proceedures, I dont have it memorized but it can save you $$$$. I put 3 sets of 02's in my truck in the last year.....yikes!! I had EEC computer problems. They do go bad, I had a remand unit from Ford last 30 days exactly, $350, they would not warranty since it;s a 4.0L in a 88 BII, went to the junk yard, got a EEC for $45, works perfect.

 

[Jag]

Check you temp. sensors, cold and hot with an ohmeter. There should be at least a 200 ohm diff. They give feedback info. to the computer regarding air and water temp. If one of them is bad, it can trick your computer into thinking the engine is cold, and forcing it to run in a cold/rich mode. These are just thermal resistors and they do go bad. The air charge sensor is located on the intake manifold downstream from the throttle body and is easy to get at. The temp. sensor is next to the thermostat, so unless you want to drain some antifreeze to take it off to check it, get a ohm reading cold, then recheck it when the engine has warmed up.

How do you know it's running rich? Smoke out the tailpipe?

If your trans is acting funny, another thing to consider is the vacuum diaphram on the auto. trans. Check the hoses on the vacuum tee on the left side of the engine. If they are full of ATF, then the diaphram is bad, causing the engine to suck ATF, and will cause your car to smoke.

 

[redthunder]

the Intake Air Temp sensor is towards the back of the intake right? I think I'm checking the right one and I'm getting 0 on the sensor AND on the wire side....hmmm.
thing that worries me is the 0 on the wire side. shouldn't there be something there.
I know it's running rich cause I'm getting black sooty smoke, black plugs, and 110 miles to the last tank of (premium...ouch) gas. Oh yea..when I pulled the upper plenum, the inside was VERY wet with fuel.
The vacuum lines all look good. No ATF in them.

Thanks again guys

 

[Tiger]

Most likely IAT )intake air temp) sensor. If not, try pulling apart the IAC (idle air control), make sure theres no crap in it and put it back together end try that. Also, leaking injestors will cause it to overfuel. Check fuel pressure.