How to pull codes from a 91 Explorer

[Blown&Injected]

Damn thing ran great until this winter 1991 till now

My 1991 Explorer idles like it has a BIG cam in it. On the throttle it breaks up in neutral and in gear - but not all the time. Catalytic smells like rotten eggs (hot exhaust like lean???)

If it were the ignition, I believe it would rev in neutral and not under load. Runs bad when cold on start up, seems to be a bit better when warm.

The problem started all at once. Fine for 11 years, then one day bam!

I just bought a gauge to check the fuel pressure. The fp gauge I use on my GN craped out last year anyway. Maybe just a clogged fuel filter - yeah right, I would never be so lucky.

How do I pull the codes and what do they mean, or where can I get a list of what they mean if it is just a flashing light type thing?

Any Ideas?

TIA,

 

[TurboJim]

Pull the vacuum hose off the FPR with the engine runing or system primed, and see if raw fuel comes out of the reg. If not, verify the canister purge solenoid is closed. If so, verify the EGR isnt stuck open with carbon. After that, you'll need a scan toolk to check DPFE sensor and stuff like that.

Oh yea, make sure the vac hose to the MAP sensor isnt off/broken

 

[Blown&Injected]

Always there to help a brother!

Thanks Jim,
Lots of snow on the ground but I'm gonna do some checkin' today

 

[Blown&Injected]

Just went for a ride, I burned over nine gallons of fuel in about 75 miles! -- So much for the lean idea.

Jim, or anybody, how do I verify the the canister purge solenoid is closed?

No fuel out of the fpr vacume line.

Thanks!

Damn the heater core just went in my Pontiac! when it rains it pours Ahhhhhhhhhh!!!!!!!!!!!!!

 

[TurboMike]

Go to a parts store and buy one of those 20.00 code readers. You can do it with a analog volt meter and watch the needle sweeps. My first thought was the same as Jim, how about a open EGR... those are bad to trap carbon.

 

[Peacock]

Hey there! I am a Ford dealership tech and I hope I can help you some. The only way to pull codes on the EEC4 Ford's is with a scan tool. From your deseciption, it sounds like you have a MAF problem. Try unplugging it while it is running and if it runs a little better, then that is what is wrong. DO NOT us a aftermarket MAF! I have never seen one work right. A new Motorcraft unit should run in the $150 range. Make sure you get the calibration number off the drivers door jam to give the parts guy!. HTH! Let me know what you find.

Jonathan

 

[Blown&Injected]

Hi Jonathan:

I am glad to say Welcome to the Board! Thanks for the help

Hi Mike - Glad you are still hanging in there errr here

 

[turbojimmy]

Originally posted by TurboMike
Go to a parts store and buy one of those 20.00 code readers. You can do it with a analog volt meter and watch the needle sweeps. My first thought was the same as Jim, how about a open EGR... those are bad to trap carbon.

I think you can do it by counting the flashes of the Check Engine light, too. My Mustang was that way, so was my dad's Lincoln. You have to short a couple of terminals on the EEC-IV test port. If memory serves, it's under the hood, up front, on the right side. My bro in law has a '90-something (early 90s) Explorer and I did some trouble shooting for him. He had similar symptoms. The problem was EGR related I think, but not the EGR itself. Some other valve. I'll have to ask.

Jim

 

[87GP]

It's been a while but, under the hood, you can run a jumper from one of the terminals on the link to a little pigtail. Use a test light from one of the other terminals to ground. turn on the key and watch the test light flashes. Turn on the engine and watch the other codes flash.

Shoot!!! I don't have my manuals here!!! Wish I could be of more help. I'll get my stuff. Right now I'm 90 miles away from my tool box.

We used to pull codes all the time from the big three when I was working at Tune-Up Masters. I know I know, I don't work there anymore.

 

[Blown&Injected]

Thank You All!!!!

I'm gonna do some work on it today. It is defiantly dumping fuel. Drove another 50 miles and burned another 1/2 tank.

Disconnected the MAF and it got a lot worse.

No fuel coming out of the fpr vac line.

Detailed info on flashing light/check engine light procedure would be appreciated (the next time you are near your tool box - 90 miles is a long way to travel)

 

[turbojimmy]

Originally posted by Blown&Injected
Thank You All!!!!

I'm gonna do some work on it today. It is defiantly dumping fuel. Drove another 50 miles and burned another 1/2 tank.

Disconnected the MAF and it got a lot worse.

No fuel coming out of the fpr vac line.

Detailed info on flashing light/check engine light procedure would be appreciated (the next time you are near your tool box - 90 miles is a long way to travel)

Check this out:
http://members.aol.com/traumapir8/EEC.html

Your test port is probably not where it's pictured on that site. According to my manual:

"The connectors will be located on one of six areas:
- Near the firewall (right or left side of vehicle)
- Near the wheel well (right or left side of vehicle)
- Near the front corner of the engine compartment (right or left side of the vehicle)"

So, the bottom line is they could be anywhere. I think my brother-in-laws (on his '94 Exploder) was on the RH side, up front. Just behind the headlight or thereabouts.

Jim

 

[87GP]

The above link shows how its is done, although if you've never done it before it might be confusing. Just read it carefully. I mentiond using a test light also but it's not nessessary(sp?) we were just too lazy to walk ALL the way around to get inside

The STI was the "pigtail" I was refering to.

One quick note, when you jump the pigatil to the link DO NOT let the jumper touch any positve/12v source!!!! If you do the smoke in the computer will be released

 

[Blown&Injected]

Jim Testa:
Thanks, I got your e-mail. That is what I was lookin' for.

AND

Thanks to you all!!! Your help is so very much appreciated!!!

I got a Haynes Manual. I was surprised to see the jumper/meter/check engine flashing light procedure in that manual. It also has the definitions for the codes.

Did an initial code check an a ton of codes came out.
I then cleared the codes and went for a ride. Same trouble, check engine light came on, I went home and did the check codes procedure again - However:

I noticed that the tests should be done in order of a code might be missed. Since I did not do this, I am gonna start over in the morning. I also was not careful to notice when the codes went from Hard Codes to Continuous Memory Codes.

 

[NJTurbo]

If you still have a problem. E-mail me Ford Service Director Here.

 

[Blown&Injected]

Thanks again for the help and ideas with the problem with my 91 Explorer.

I cleared the codes by disconnecting the jumper while the codes were being displayed. I then went for a ride to warm-up the truck - seemed to run fine while cold, but the next day it ran bad when cold, it has run OK when warm too. It will occasionally run OK at random times, but only for about three minutes - then back to the stumbling.

After warm-up I again checked the codes:
KOEO
11
11
pause
1
pause
45
45
EO
3
turn wheel and press brake
long pause
1
stab gas pedal
42
42

Went for another ride and drove until the CHECK ENGINE light came on:
KOEO
11
11
pause
1
pause
41
45
41
45
Same results from EO test.

This is curious to me based on what my Ford Explorer 1991 thru 1999 Haynes Repair Manual (1999) says. Since the manual covers many years, perhaps it is not entirely accurate???

Why would it say 41 - continuos memory - no heated oxygen sensor switch detected, right side; and then say 42 - engine running - O2 indicates system rich, right side.

Also, 45 - continuos memory - DIS coil pack circuit failure. Would the coil pack cause the fuel to go berserk? - 85 miles to a tank? I believe a bad coil pack would cause the engine to perform as bad as it does, even to cause the fuel economy to go down, but 6 MPG's??? - from about 300+ miles to the tank to 85 miles per tank. I would think that the system rich condition that the O2 shows would cut and correct the fuel. But then why would it know it is rich and not correct???

Sorry for the length, trying to provide all the details.

Thanks,
Steve

 

[turbojimmy]

A bad coil pack can cause the symptoms you're describing. It's almost exactly what happened when my ignition module went bad in my GN. The center coil pack was firing weakly/intermittently. Unburned fuel was causing a *very* rich condition. Idle was really rough and I had a hesitation off idle. It wasn't too bad off idle, though. Gas mileage was real bad, too (relatively speaking).

I'd see if you can find a coil pack to swap out before you buy one.

Jim

 

[TurboJim]

Originally posted by Blown&Injected

Why would it say 41 - continuos memory - no heated oxygen sensor switch detected, right side; and then say 42 - engine running - O2 indicates system rich, right side.

Also, 45 - continuos memory - DIS coil pack circuit failure. Would the coil pack cause the fuel to go berserk? - 85 miles to a tank? I believe a bad coil pack would cause the engine to perform as bad as it does, even to cause the fuel economy to go down, but 6 MPG's??? - from about 300+ miles to the tank to 85 miles per tank. I would think that the system rich condition that the O2 shows would cut and correct the fuel. But then why would it know it is rich and not correct???

Sorry for the length, trying to provide all the details.

Thanks,
Steve

Its giving you a memory code because the O2 isnt reading anything KOEO, so it cant fail it. If you got that code KOER then it would be "current"

Also, in case the manual didnt say, Fords self tests need to be done engine warmed up as they will fail coolant temp and air temp sensors if they read cold (Will give you like CTS out of range) and you can change them till yer blue in the face if you dont know the engine must be warm, and the code will never go away

I would start by doing the code 45 pinpoint test. You do know Fords stire the codes in order of importance right? in other words, the 45 is more important than the 41. ANd the 45 could be CAUSING the 41

If you need the pinpoint test, let me know. I'll print it and fax it to you. I dont know how deep the Haynes manual goes.

 

[SinistrV6]

just FYI

I won't use AutoZone for anything else, but they will pull your codes for you for free and tell you what they are. Did it on my '99 Suburban recently. Gotta have a scan tool for newer stuff and why buy it if they'll do it for free.

 

[NJTurbo]

What is your fuel pressure

You need to perform key on engine off fuel pressure, key on engine running fuel pressure test and also Fuel pressure leak down. That is it for now let me know what it is and i am looking up these codes will get back to you. Is this a manual or Auto

 

[Blown&Injected]

The test was done with a warm (at normal operating temp) engine. I have no idea what the pinpoint test is and could not find anything about it in the Haynes Manual.

My Fax number is the same as my voice line (301) 890-3614. just treat it like a regular fax even if you hear a voice - THANKS!!!

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It is a manual transmission, I'll check the fuel pressure and get back to you later - THANKS for checking.

-----

Got a spark plug tester that goes in between the plug and plug wire - maybe that will reveal a bad coil - the plugs are only a couple of months old - wires are about 5 years old but could they go that bad all-of-a-sudden?

Thanks All,