Over the last ten days my check engine light has came on several times. If I stop the engine and restart it the light does not re-appear. At any rate, it tells me that my truck is trying to tell me something. If I went into a big explanation you guys would probably tell me to pull codes and report back. This leads me to my questions. I've been trying to find instructions on the I-net and am becoming confused.


Q #1: Do I have an OBD1 or OBD2?


Q#2: Does the light need to be on to get the codes?


Q #3: Is a scanner recommended?


Thanks in advance guys.

 

'92 trucks are OBD1
No, the CEL light need not be on to get codes
No you don't need a scanner, it's easier to read codes with one but, the codes can be extracted with a jumper wire, see the how to sticky for the procedure
Whoops, that's tech info not how to

 

Here is the information wag53 was looking for:
Fuel Injection Technical Library » How To Run a Self-Test

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By the way, I don't think any Ford's at least were called OBD1 until after there was an OBDII. EEC-IV (EEC-4) was what they were called at the time. If you're searching you might find additional info if you look for EEC-IV as well (although they seem to be called OBD-1 more often on here anyway).

 

Thank you very much. I'll get with codes in the next couple days. I appreciate your responses.

 

It was just OBD before OBDII.
This was not just Ford but mandated to all auto makers. But before OBDII they all had different plugs and ways of implementing the OBD.

 

My (admittedly imperfect) understanding is that OBDII was the first federally mandated system. From that point on the feds made it simpler for the aftermarket (as well as government inspection facilities) to hook up to a vehicles computer because they were all the same after that.

Prior to OBDII my understanding is that all the manufacturers had their own systems. I don't know if any company officially called theirs "OBD" or "OBD1", but I'm pretty sure that Ford called their last non-OBDII system "EEC-IV".

"OBD", or "OBD1" may or may not be technically correct for another make, but I'm pretty sure that it's not technically correct for Fords. Although it's so commonly used (at least on this board) that perobably more people know what you're talking about than if you call it the technically correct name.

My point to the OP though was that if he's looking for info from Ford, or looking up any particular scanner he might have better luck calling it by it's correct name. Particularly the scanner, because if you get an "OBD1" scanner for a make other than Ford it probably won't hook up to (let along read) a Ford EEC-IV.


edit: according to Wikipedia (so it MUST be right!), "OBD" (for On Board Diagnostics) was a generic term not specifying anything in particular, but referring to any diagnostic system that was included in a vehicle. Then in '91 California required all vehicles sold there to meet some minimum "OBD" requirements, but there was no specified standard way that they needed to meet it. "OBDII" was the first mandated standard, and the California '91 requirements started being called "OBD1" after that. For what that's worth...

 

By the way Ford's first one was EEC-1 and now it is up to EEC-7. There were no skips in the EEC numbers, 1-7.
EEC-IV is the most talked about on this forum and we get some one asking about EEC-III sometimes but EEC-1 & EEC-2 were for older Fords.
By the way OBD-II was the start of EEC-V.
My scanner read them all, all makes with OBD-1 & OBD-II.

 

I am off on Wednesday and I'm going to check codes at that time and will report back. Thank you for all the replies.

 

Good luck! I checked codes without a code reader for months but finally decided to spend the $25 on one. Here is what most of us use:

It's very helpful to buy the extension cord, this allows you to hold the code reader inside the cab of the truck. I know, it's MORE expensive than the code reader!

You don't have to get the extension cord but it is nice to be able to hold the reader while you work the keyswitch for some tests. But not required for just checking codes. So by all means skip the extension cord if money is an issue. You can always use a helper if you get that far.

 

87-XL-Squared: Thank for the links. It's appreciated (& ordered).

 

Actually, the extension cable can save you money. If you need to run a bunch of tests, and the buddy you enlist to help you out drinks a lot of beer, not having the cable can run into some serious coin.

 

Codes pulled.

The presenting problem: Since it has turned cold my truck has problems after it starts. It will hold an idle at ~650, but once you push on the accelerator it will lope and surges at idle and dies. It will start right back up. If I hold the RPM's at 1100 or so for about 60 seconds it will then idle nicely at 6-700 RPM.

In the last two weeks the CEL has come on 4 times right when the engine gets warm. If I shut it down and restart the engine the CEL does not re-appear.

I have also noticed that my gas mileage has went into the toilet in the last month.

Codes:
KOEO: 111
CM: 122, 173, 181, 334
KOER: 312

Any help would be very much appreciated. Thank you.

 

Codes 173 and 181 both are telling you its running rich, you need to test the fuel system do a static pressure test make sure its not sucking fuel via the FPR vac line.

Goes with your stating "I have also noticed that my gas mileage has went into the toilet in the last month".

If the age of the O2 sensor is unknown it wouldn't be a bad idea to replace it, need to check out the fuel system regardless though, make sure there isn't an underlying issue causing it to run rich first/same time. IME sensors tend to fail "lean" and not rich but same time doesn't mean it doesn't occur can't or won't happen.

334 suggests your EGR valve isn't fully closed or problem in the circuit, make sure the valve is closed and might be easier for ya if for the time being while you're troubleshooting make sure it stays closed.

Then 312 secondary air misdirected upstream during test. Might be you have a vac line connected wrong or not connected whichever the case may be.

Diverter valve dumps the secondary air flow directly to atmosphere no vacuum is supplied to it (in otherwords its bypassed), the diverter valve sends the secondary air flow to the cat when vacuum is applied to it.

You don't want engine vac supplied to it all the time, if so that is a problem and reason TAB can't stop it. Don't want it pumping secondary air to the system all the time, especially up stream of the O2 sensor.

 

Thank you for your reply. How does one do a "static pressure test"? Can you tell me where to find the FPR (Fuel Pressure Regulater) Vac line?



Sounds like sage advice. I've owned the truck for a little over a year and have never looked at the O2 sensor.

What is an IME sensor?

I am going to thoroughly check all vaccuum lines tomorrow. Jeez, there seems to be a jillion of them. Being the old fart that I am I sure miss the old days and older engines.

Thank you for your help. Now at least I have a direction to to go. All of this is new to me. You're never too old for a new adventure I guess.