I have a 1992 F250 with the 5.8L engine and it normally idles around 600-750rpm, recently the check engine light comes on and then it idles at 1000 then if you allow it to idle a while or drive in a low gear (its a 5 speed) it almost always goes out and fixes its self. Its been a plow truck all of its life and i use it to go to school and for my buisness. Its engine compartment is a dirty plenty of black dust could this have anything to do with it?

 

The first thing is to pull the codes. That will tell you a heck of a lot and point you in the direction to go.

 

would it be worth buying my own code reader or just go with a trusted auto place?

also tonight i drove the truck and had no issues, but this morning it did the glitch then corrected when i shifted to first again

 

That's an individual decision based upon whether or not you plan to do most of the work on truck and if you plan to keep it. I bought this one based upon recommendations on this forum and have been pleased with it. For $25 it's hardly a major expense and may well pay for itself many times over if it saves you from buying parts that you don't need.

 

Alright ill look into that code reader for sure, Thanks!

Also how difficult is it to pull the codes? Theres an auto shop 3 min up the road so if its a real time consuming thing i could just take it to them, im 17 this is my first car so most of these things will be my first time with this stuff, but the majority of the work will be me and a mechanic friend of mine.

 

Pulling codes is easy. You just plug the code reader in and follow the directions. If you don't order the extension kit it really needs two people, one in the cab and one reading the reader.

Going from memory it's something like this:

1) set up and plug in code reader.
2) turn on ignition but don't start engine.
3) Press the test button on the reader.
4) Wait for codes to be retrieved until the blinking black square hasn't blinked for 30 seconds.
5) Turn off code reader, turn off ignition.
6) Resolve any KOEO issues. Previous codes can be retrieved even with the reader disconnected from the truck.
7) Once KOEO issues have been resolved, start engine and warm it up.
8) Press test button on reader.
9) Immediately after the number of cylinders have been reported, turn the steering wheel half a turn and hold for 3-5 seconds, then press and release the brake, then turn on then off the OD lockout if present.
10) After something is displayed on the tester, don't remember what offhand, rapidly depressed the gas pedal to the floor and immediately let off.
11) Wait for the blinking black square to stop for 30 seconds, turn off and your're done.

It takes less than 5 minutes total. The instruction manual does a very good job of stepping through it. A local shop that's friendly might be happy to do it for you, but if you'll be doing the work yourself then you'll want to be retesting as you fix things. Depending on the shop, after a few tests they might get tired of doing it for free while you fix your own truck.

 

autozone told me that due to the trucks age it cant even run codes, however they used their software and diagnosed that my Throttle position sensor was the problem. i pushed the cable ends together into the engine and have only had the issue a few times after.

 

It's not surprising that Autozone couldn't read the codes since the truck is a pre OBD-II. I doubt any of various auto parts stores will be able to read the codes. It's going to take doing it yourself by counting the flashes of the CEL light, buying your own code reader, or paying a repair shop/dealer to do it for you.

I don't know what "software" they used other than some kind of troubleshooting step-by-step type thing, but without determining the actual codes being given by the EEC, it's just shooting in the dark while blindfolded.

So maybe fiddling with the connection helped, maybe it didn't. In any case you are still having a problem as indicated by the CEL light continuing to flash. If you want a reliable vehicle, which I presume you do since you say you rely upon it for your business, you really should figure out what is going on.

 

Lol... it "can't even run codes" huh?

Most AutoGroan employees are clueless unless they can plug the OBDII scanner in. Which, in most cases, they will then try to sell you a part you may or may not need based on what the fault code is/was. Definitely not the right way to do it... the fault code only tells you what the computer sees as a problem, not necessarily what the problem actually is.

 

Exactly what Dixie460 said. This used to drive my father nuts being an old school trained mechanic, old cars didn't have eec so there were no codes. New guys came into the shop and didn't know what to do if the code didn't tell them what to do.. Codes point you to the correct system, sometimes they give you more, but be a critical "listener".

Just so you're aware, there is a way to read the codes from your OBD-I equipped truck with a paper clip. The how-to is in a "sticky" thread at the top of our forum.

The dirty engine bay usually wouldn't be an issue, but I would clean up the outside of the cap on the distributor and take a moment to look at the contacts inside. Greasy grime can attract enough crap to cause miss firing or cross firing if the spark plug boots aren't in great shape.

 

Use a jumper on your obdII Google how to get codes on you tube for your year truck and boom done but pay attention to the dash light. The obd is on drivers side fender when you lift the hood

 

[QUOTE=dixie460;14709880]Lol... it "can't even run codes" huh?

good point i should watch my grammar ... what can I say.. public schools...

Yeah the guy who helped me was asking for the Ford guy...since i was knew more on the car than he did. Anyway, so what i need is the Inova 3145? since thats what ive been recommended and that will work on my truck?

 

I think dixie460 was poking fun at the Autozone employee's lack of knowledge, not your grammar.

Becoming self sufficient can not only save you money, but be its own reward. Review the specs for the Inova code reader and determine if it is compatible with your vehicle. Quite frankly, if you are unwilling or unable to take that step it's highly unlikely that the code reader will do you much good. Hint, look for the document titled "vehicle compatibility" on the Amazon.com page linked to above.

 

In the future you dont need a code reader. you can check the codes anyplace as long as you have a piece of wire. count how many times the check engine light blinks. Print off the code cheat sheet and throw it in your glove box.

 

Oh I'll be the last person to correct someone's grammar, I don't use the right grammar either!

As for the Innova vs. reading codes with a jumper, all the code reader does is save you the frustration of miscounting a code and having to start all over again. I'll know I'll be buying one next time I own something with an OBD1 computer system, because without fail someone or something will interrupt me while I'm counting. Lol.