Ugh... 92 Explorer Hell..

[MistahYebba]

And that leads to 5v you say? Do you reckon the codes that follow the 998 code are hints to the 998?

 

[MistahYebba]

Here's why I say this..

Check out this post.. http://www.fordf150.net/forums/viewtopic.php?t=38534

That guy was getting codes 998 and 122..

As we know, 998 means: hard fault.

122, using the link you gave me, means: Throttle Position Sensor Circuit Below Minimum Voltage

And it turns out the solution to this guys problem was replacing his TPS.

**huge edit**

I rescanned many many times to make sure I'm getting the right codes..

Turns out it's 998 and "57"... not 579!.. the 9 was from confusing it when it restarts again. 9985799857

57 is Intermittent in Park/Neutral/ Switch or Neutral Pressure switch circuit

So what's with that?

I also recorded a video of my KOEO codes.. if someone would help me read those that would be great! Or at least verify my reading.



I got :

37: System Indicates Rich At Idle

58: Idle Tracking Switch (ITS) signal problem ISC

Vane Air Temperature (VAT) sensor out of range or open - VAT

212: Ignition TACH signal was erratic (module/wiring) or SPOUT circuit fault - Ignition Systems

543: Fuel Pump Circuit Open–Battery To Powertrain Control Module (PCM)
C/O

157: Mass Air Flows Sensor Circuit Below Minimum Voltage

 

[natenkiki2004]

You have some real electrical gremlins to chase down. There's 2 things you can do; find a competent mechanic that knows electrical systems or get a multimeter and start digging.

I can't remember now but look up and see if you can perform a wiggle test on your year. If you can, that might narrow the problems down immensely. If not, you're going to want to get a wiring diagram and find something in common with a couple of those codes.

Quick & easy place to start is the battery cables.


*EDIT*
I guess you COULD unplug sensors one at a time and re-run the test. I think you're facing a short or bad wiring somewhere though, not a super faulty sensor.

 

[MistahYebba]

What are the sensors available to unplug?

Off the top of my head... IAC, MAF, TPS.. what else? I'll look into the wiggle test.

Where's the VAT sensor to unplug?

 

[murkinstock]

I think, either you have major wiring issues, or the computer is bad.

 

[MistahYebba]

But just major wiring issues out of the blue? and we can't all forget I got this sucker working by accident the other day and I was turning on and off the AC and bla bla bla nothing badwas happening.. No stalling.. Smooth idle.. IAC was plugged in..Everything was good until I walked away and took a nap...

Major wiring issues I feel aren't so off and on like that, right?

And how could the computer go bad over night? :/

 

[murkinstock]

I heard when computers go bad in these it's generally the capacitors on the PCB. Which can slowly get worse until finally they just can't give the computer the voltage that it needs. Causing it to do all sorts of weird stuff. (that's how I understand it anyways) happened to an old desktop I own, I replaced the caps on the motherboard, and it's good as new.

I know the EEC-IV isn't very powerful at all, but I imagine it's similar in more ways than not.

I'm leaning towards it being the computer. You're right, a lot of wiring doesn't just instantly go wack, otherwise it would probably be quite obvious.
Maybe where the main harness connects at the firewall?

 

[MistahYebba]

I heard when computers go bad in these it's generally the capacitors on the PCB. Which can slowly get worse until finally they just can't give the computer the voltage that it needs. Causing it to do all sorts of weird stuff. (that's how I understand it anyways) happened to an old desktop I own, I replaced the caps on the motherboard, and it's good as new.

I know the EEC-IV isn't very powerful at all, but I imagine it's similar in more ways than not.

I'm leaning towards it being the computer. You're right, a lot of wiring doesn't just instantly go wack, otherwise it would probably be quite obvious.
Maybe where the main harness connects at the firewall?

As a quick re-cap, if the IAC is plugged in, it will stall right away after starting up.

Whatever I did the other day... just plugging/replugging in sensors and vacuum lines and moving stuff and wiggling stuff... I was able to plug in the IAC once again and run the car. It was running how it should be in my opinion.

I thought I had solved the problem by accident, so I wrapped everything up and posted on here in rejoice.

When I went back later to use the truck again, the problem was back.. it stalled instantly because the IAC was plugged in.

The fact that I got it working by fiddling with stuff, I feel, rules out so many possibilities. Can't be anything "broken", because if it was broken it wouldn't have started working again. Can't be anything electrical being faulty, because if it was faulty it wouldn't have started working again?

That leaves us with things like... kinda like having a phone charger where the wire has to be bent a certain way in order to charge your phone.. I never knew why phone chargers did that.. Do you know Murkin?

Because if we knew that, that's more than likely my problem.. considering it worked one day, didn't work the next, then worked for like 15 minutes until I left it alone.

 

[murkinstock]

Contacts break, and get out of place in the charger. Or the most common case in 20+ year old trucks, corrode. That's why I thought possibly a bad connection at the firewall, which could cause tons of problems. However, it's possible it was just one wire you touched and gave it a good connection for a minute, but then it lost it again. If that makes sense? Lol I word things weird. You can try carefully checking connections and looking for corrosion... Everywhere. I don't know.

 

[MistahYebba]

Would you recommend me clearing my continuous memory codes since those could be old? And old working with the codes that are present NOW?

 

[murkinstock]

Yes! I would definitely do that! Clear them and run it again, let it warm up etc. If it will let you anyways.

 

[MistahYebba]

Unfortunately I have to disconnect my battery every time I run the test once. Me and Natenkiki were talking about this earlier in the thread.

I can disconnect my battery, and right away hook it back up again. Once the test runs through once, it won't go through again til I disconnect my battery and hook it back up again.

Weird, huh? I think it has something to do with being in the 998 hard fault mode though.

 

[murkinstock]

Whoa, that is weird. That definitely makes me think it's the computer.

 

[MistahYebba]

Another way I also noticed that I only get "one chance" to test.. if I put in the paperclip you can hear the test mode "click on" or something. If I pull it out, you can hear it "click off".. and it won't "click on" again until, once again, I disconnect the battery.

I found that out cause I accidentally knocked it out once before I even got a chance to get to the seat and turn the key lol..

Do you have ANY idea why I would get a code 37 for KOEO? Natenkiki pointed out that it's obviously not a code you should get for KOEO... at least not the "rich at idle" portion of it.

If you haven't watched the video yet, do you think I read the first code correctly as 37? It's most definitely KOEO.

 

[natenkiki2004]

Here's the thing... it may not be the computer. It could be a short and the computer is protecting itself by disabling features in the short circuit. When you reconnect the battery, it wipes memory and starts fresh. When you run the test, it realizes something is broken and shuts down into limp mode. The last thing you want to do is get a new computer and risk frying it. You need to start doing wire tests. Since it ran better with the IAC unplugged, maybe the short is in that area of the harness.

 

[MistahYebba]

Does the TPS harness count as in the area?

Once I get out of work I'm really going to just reset the codes in the CEL memory.. and then disconnect every sensor I can find to disconnect.. then run the tests again.

But can you tell me.. if the MAF sensor is unplugged, would I be getting codes such as "MAF sensor broken" if ya know what I mean?

Does it think it's broken cause it's unplugged?

A better example, does it think my IAC is broken because it's unplugged? Or does it disregard it knowing that it's unplugged?

Furthermore, what even makes a short Natenkiki...?

Hypothetically, imagine you have a harness with a male connector and a harness with a female connector.. when you put em together, what would have to be wrong with one or the other for it to ... so called, "short"?

I know nothing about electronics lol. And I know that video you sent me was full of information from ScannerDanner.. but man I just don't even understand how a car battery circuit works. I'm scared if I touch any of the metal on a battery with my hand I will explode lol.. but that's cause I dont' know how it freakin' works!

 

[murkinstock]

Here's the thing... it may not be the computer. It could be a short and the computer is protecting itself by disabling features in the short circuit. When you reconnect the battery, it wipes memory and starts fresh. When you run the test, it realizes something is broken and shuts down into limp mode. The last thing you want to do is get a new computer and risk frying it. You need to start doing wire tests. Since it ran better with the IAC unplugged, maybe the short is in that area of the harness.

That does make a lot of sense. However, what about it spitting out all the other codes? Wouldn't it just spit out one 998 or whatever? I'm going to do some research!

 

[MistahYebba]

That does make a lot of sense. However, what about it spitting out all the other codes? Wouldn't it just spit out one 998 or whatever? I'm going to do some research!

Who knows how old those codes are is all I can say. :/

Plus it does only spit out one 998! Remember that the big bundle of codes I have is from KOEO.

The 998 is KOER, and it comes along with only one partner code.. 57.

So Naten could be right, but finding a short that all the sudden developed overnight is going to be a pita bread with hummus.

 

[murkinstock]

Who knows how old those codes are is all I can say. :/

Plus it does only spit out one 998! Remember that the big bundle of codes I have is from KOEO.

The 998 is KOER, and it comes along with only one partner code.. 57.

So Naten could be right, but finding a short that all the sudden developed overnight is going to be a pita bread with hummus.

Oh, so you already cleared the codes you got from several posts back? And they didn't come back? So yeah, I would definitely start inspecting all the wires and connections you can.

 

[MistahYebba]

Oh, so you already cleared the codes you got from several posts back? And they didn't come back? So yeah, I would definitely start inspecting all the wires and connections you can.

No no, I've never cleared my codes.

The codes I got from several posts back at still there--those are my KOEO.

Then I have different codes for KOER--still there as well.

They're all still there, I was just saying; 998 is a KOER code.

All those other crazy codes are KOEO.

I have 2 codes for KOER and like 5 codes for KOEO.

**edit** but when I get out of work I will clear my codes and see what I'm left with.