Need help! Not sure what this does!

[gschwitz6]

So the past few days I noticed that my 84 ranger 2.8 4x4 has been running a little rough... The acceleration isn't too bad but it's idling really high... I fixed the timing last week so I could go take emissions and it seemed to be idling high... I kinda tried messing with the carb, but not very much. (yes i realize i shouldn't have been adjusting screws if I don't know what it is) So I got home today and looked under the hood and this screw (see picture) had fallen out of the hole it was in... from what i could find online it's the fast idle screw? I just need to know what it is and how to adjust it before I start driving around again... any help would be much appreciated!

 

[Ruffinit]

Do you have a Chiltons or Haynes manual?
Both of those manuals walk you through the step by step in adjusting your carburetor correctly. I can't tell you what the screw is possitively without referencing the manual and that's at home. You really need to pick one up if you don't already have one.

When you DO pick one up; go through the alignment (doesn't take too long), then go in the house and have a cup of coffee. Now go back out and do it again. Trust me on this. Once you get it set up properly, you'll have very little problem with it.

 

[Mark_88]

Could be or could not be a problem...I have several screws sticking out of my carb that do absolutely nothing other than plug the hole they are in...

The rough idle could be plugged jets...could be water in the gas...could be that something has shaken loose...could be a vac line has come off (high idle and rough)...could also be your choke is sticking...

To check the jets you actually have to remove the top of the carb...not as hard as it sounds...but it is a rather delicate job on some carbs since the float and needle usually come out with the top of the carb...and that is where it gets a bit tricky...removing them is easy...getting them back in side takes a bit of patience...

I would suggest to first check for vac lines that may have popped off or leaking slightly...

Remove the breather and check what position the butterfly is in when it is off and after it has ran for a few minutes...the butterfly should be closed when off and wide open after warm-up...if not...you have a choke problem...if so...move on...

I have a Haynes manual and the information on carbs leaves a lot to be desired...they don't cover all carbs...just major points and troubleshooting...the AARC had complete diagrams with parts listed in an exploded view so you could see what part you needed or what may be a problem...unfortunately, that site has been shut down or severely limited...

A Chilton manual may have more to offer...but you're vehicle actually precedes mine so the earlier version of Haynes may actually cover your carb...not sure and you can't tell till you buy them because they are sealed...check to see if one is open in the store and look for the information you need...if it has it...bingo!

Did you happen to buy gas at a place you don't usually buy from? You could try dumping some of gas line anti-freeze or similar product if you have not been doing so...moisture is your enemy when it comes to gas and carbs...

 

[gschwitz6]

I don't have a haynes or chilton manual... I need to go pick one up but i'm really broke right now and spending 25-30 dollars on a manual isn't an option for me right now... I was just hoping that it was a problem with the way it was adjusted and i could do it quickly... I'll definitely pick one up when i get paid! I really just want to know since this is my daily driver that it won't do any serious engine damage by driving it for a little while like this... I'll check my vacuum lines and make sure they are all ok... the rough idle started a few days after I got gas last so i don't think it's that and I run seafoam on almost every tank... I'll take apart the carb if I've ruled everything else out but I would like that to be my last resort... Thank you guys for your suggestions though!

 

[Mark_88]

OK, I just checked and the on-line repair manual is functioning...whacky...

Fig. 5: Exploded view of a typical Motorcraft 2150 carburetor




This is the Motorcraft 2150 carb that seems to be one of the options on your truck...not sure if it blows up well, but it is in the repair manual...if you go to the link you can follow the steps to log in and get more information...

http://www.therangerstation.com/forums/showthread.php?t=319

 

[gschwitz6]

thank you for finding that! that looks like my carb and from the exploded picture it seems like that just might be a screw for a heat shield that is no longer in there... I'll double check but that would be kinda funny...

 

[straycat]

I don't have a haynes or chilton manual... I need to go pick one up but i'm really broke right now and spending 25-30 dollars on a manual isn't an option for me right now... I was just hoping that it was a problem with the way it was adjusted and i could do it quickly... I'll definitely pick one up when i get paid! I really just want to know since this is my daily driver that it won't do any serious engine damage by driving it for a little while like this... I'll check my vacuum lines and make sure they are all ok... the rough idle started a few days after I got gas last so i don't think it's that and I run seafoam on almost every tank... I'll take apart the carb if I've ruled everything else out but I would like that to be my last resort... Thank you guys for your suggestions though!

Check Ebay out. I see them all the time for many different years. Maybe you can find yours there. I bought a few on Ebay and got great deals on them.