I've found that with my 94 Mustang GT nobody could read the codes either. Its a rather simple affair with the paperclip or jumper wire. Here ya go.
http://fords.kilonet.org/ken00/EECIVQT.pdf

 

You guys rock! Thank you. Here's the "progress":

I went to the library (small town library) and looked at some old Chilton's manuals but there were no pictures or descriptions of EGR valves, MAF sensors or anything related to my problem. They are very generic and not specific to the Explorer. It did tell me how to remove the engine, though.

I went to Autozone again (slow learner) and they did not have the code reader for my car. I bought a Haynes manual on Explorers from 1991 to 2001 ($ 20). Unfortunately the images suck and are not always of my engine. Still can't find the EGR valve.

Bought security torx wrenches ($ 10) to look at the MAF sensor...it is CLEAN and I did not want to try to wipe such a delicate part that looked so clean already.

I will do the paper clip thing and see if I can get any codes, I promise. But will somebody please tell me where the EGR valve is? I can't find it - I know what it must look like and what should be attached to it, but can't see a thing!!!

 

Depending on which engine you have, there are 3 parts to the EGR system. The valve itself is the thing that looks like a space ship, which holds the diaphram, and has a hose(s) usually going to a sensor, and then to the intake and exhaust. The sensor is connected to a filter on the newer cars and trucks (new as of 96) not sure about older than that - might only be one or the other....

good to pull all the hoses, and clean every connection, but I really don't think it would cause your problem. It would cause it to run really rough, but usually not die all the time... but I guess it's possible - again - the code(s) will tell the story.

On the OBDII 96+ 4.0L engines, you have a DPFE sensor, and a filter, but I don't know if those are on a pre-OBDII engine.

Forget autozone for your truck - you need to either do the paperclip thing, or go to a real mechanic that will use a real scan tool to get the OBD1 code(s) They do make OBD1 scanners, and many are good used for not too much money - If you are going to keep the Truck, I'd buy one if it was me - I like to see the code on a display, instead of having to remember how many times, and the order of pulses the CEL does with the paper clip thing... but, you can get it that way too -

RE: EGR valve, etc - if you just replaced these items without making sure that's the problem, you just spent about $200 for nothing... (or less, if it is only 2 of the 3 parts that could fail) This is why, even if it costs you $40 to have someone that uses an $8K scan tool to read the codes, it would be worth it - or jumper wire for free....

 

As I understand it, '93 Ca emissions package came with an EGR system, but '93 Federal emissions didn't have an EGR system. It's possible you don't have an EGR system to find.

 

I have been studying diligently. I don't believe I have an EGR valve/system. None is visible and I found a reference stating that it doesn't.

My engine, I believe, is a 4.0 liter pushrod V-6. This means it has the EEC IV (OBD-I) system. And again my Explorer is a 1993 model.

My problem is a bit of a catch-22, I'm afraid. I can't keep the truck running long enough to go to a real mechanic, and I am fairly sure the local mechanics, even if I could reach them, would simply replace item after item until the truck runs and charge me accordingly. I could spend more than the truck is worth, but why?

This is what I am afraid will happen with the code thing: since the truck runs crappy it will not be able to provide useful info. I am still looking for the "paperclip trick" code instructions. A very nice member sent me instructions for using a "STAR" tester which I do not have. BTW: where is the connector for the code tester? Is it the loose female connectors behind the fuse box on the passenger side of the engine compartment? It is not labeled.

In any case, does anybody know of instructions to the "paperclip" method to get the codes for the 1993 Explorer?

 

This is correct MrShorty...another reason not to listn to the auto parts guys too much.

Also, it's important to know that when you read codes off the computer, the codes will not tell you what is wrong. In other words, the computer will not say "bad fuel pressure regulator, must be replaced". Actually you won't getting anything relative to fuel pressure since it's not even monitored.

You will be able to see what the computer sees...as in "Bank 1 O2 not switching/lean". Now you need to go off and figure out why bank 1 is lean and fix theroot problem.

I can give you a link to a ton of good info on ealry Ex's if you send me your email address. The admins wont let me post web links anymore.

 

Don't keep looking for the EGR unless it's a Ca car.
Those are the connectors for the OBD1 diagnostic reader. Should be 2. A big rhombus looking one and little single lead one.
There is a Ranger web site with the paper clip instrructions on it...but again, I can't post it.

 

That was my point, I didn't mean that the computer is going to tell you the exact problem - but at least you can pinpoint the problem area, so that if you have it repaired, you know that they are being honest with you, or if you do it yourself, we can all help you much better.

Also, I disagree - A GOOD mechanic will not just expect you to keep repairing it until it runs - if you tell them you want codes read, and that is it, you can start there - yeah, they might charge you, etc, but it's important info. Any mechanic that will not just read codes, and then force you into guessing at the problem... is not a the kind of person you want to deal with, but I know it can be tough to find an honest mechanic... (sort of an oxy moron)

I know it's a pain, cause you can't even get it to run, to take it to anyone, but it's a BIG piece of info that you really should have before just guessing... Right now, you can even tell if it's fuel or spark related... so, you can guess at fuel, and replace 10 different things, and still be wrong... or vice versa...

You're just trying to make an educated guess at least - and without pulling the code(s) it's not all that simple :-)

 

OK, I have researched and found instructions for the paperclip method as far as connections go. I have tried to run the part of the check with the engine off, since the engine runs extremely rough and then dies.

The engine check light flashes a million times at different intervals. Seems to be doing what it's supposed to. Now I have to master the reading of them. It seems that between long intervals there are many code numbers...just as I feared...is this normal?

 

OK I THINK I HAVE CODES!!!!

I just spent a lot of time with my face glued to the Check Engine light...how about these?

117;122;112;513;565;556;629;566

Any suggestions? I hope this helps. Thank you for "pushing me" to get the codes. Please remember these are with engine off.

my email is trobbiag@yahoo.com

 

Hope this helps,

I would be looking for a crushed, burned or severed cable/harness.

112; air charge temperature sensor below min Voltage
117; Engine coolant temp sensor below min voltage /254 indicated
122; Throttle position sensor below voltage
513; PCM internal voltage failure
556; fuel pump relay primary circuit fault
565; canister purge valve solonoid circuit failure
566; 3-4 shift solonoid circuit failure
629; Converter clutch, or lock-up solonoid circuit failure

 

It could be a PCM that is toast as well. That would explain why all the codes went at once. However, check all of your harnesses first before looking into buying a used pcm as they are a little spendy.

 

What about this: "A common problem on this vehicle is failure of the Positive Battery Cable. This failure may prevent the vehicle from starting." From a reliability rating website?

 

The KOEO test yields two sets of codes Key On Engine Off (KOEO) codes then a single separator pulse, and then Continuous Memory (CM) codes. The next thing would be to identify which kind each code is. I wish FTE would allow links to competing web sites, I've got a nice post on another site that I think would help explain. Some thoughts:

KOEO 513 should be fairly easy to diagnose. From Mitchell The manual doesn't mention checking the power supply wiring to the computer, I would add that in there, but this looks like a good candidate for a starting place. Also double cdheck and make sure you're counting the flashes correctly. Satisfy yourself that you've correctly counted the flashes, then satisfy yourself that battery voltage is correct and the computer is getting that voltage. At that poinht, you're probably looking at replacing the computer.

In some ways it's good that you finally got the codes read. PCM's don't fail very often, so that would have been one of the last "guess and check" things that might have been suggested.

 

Ouch that's harsh! Glad you got the codes and so now you know the engine doesn't have to run to get stored codes. As soon as you disconnect the battery, the codes will get wiped out.

So its obvious the KAM - keep alive memory - is working. There is a seperate power feed from the power dist box to #1 pin on the PCM cable that gives 12 v to KAM at all times...untill you disconnect the battery of course.

I mention this seperate power feed as a clarification point...I don't have time now to scour over the schematic...but I think the car will start and run without the PCM actually having power. Furel pump relay is power off the ignition switch and so is the ignition control module...that's about all you need to start the engine.

So...I would first look at the PCM power relay. I would not think it is the fuse upstream of this relay since the fuel pump is powered off the same fuse and it obviously works if it starts at all.

All those systems below expected voltage sounds like the PCM just has no power. I've never seen such a myriad of codes before...pretty cool. If the relay is OK, I would start thinking about a new PCM. There is no way the PCM connector came loose...not the way it's bolted into place and up out of the way behind the front passenger kick panel.

Oh and I think juat as the "what ever it was" failed, the PCM triggered all those faults and that's how they got into KAM. It would be interesting now to disconnect the battery, reconnect and fire it off to see if those codes cam back.

Sorry I gotta get the kids to bed but post what you find.