I just finished rebuilding a 77 302 for my 84 F150 (which originally had a 300) and it ran fine for about 50 miles then the idle went to heck. Idled rough and didn't change if you removed the number 7 plug wire. I have a Holley 4412 and I went nuts adjusting it to try and solve the rough idle. after 2 days of adjusting i jumped on the internet and bang the answer to my problems. EGR!!
I check and sure enough it was stuck open. Turns out I had the vacuum lines hooked up wrong. You great people here save me pulling out all my hair and pounding lumps onto my forehead!!

 

Glad that we could help!

Welcome to FTE, there are a lot of great folks here with absolutely incredible amounts of knowledge...

 

And???

 

I have a 1979 F-250 that is hard to start in the morning and stalls intermittently while I drive it. When it gets warm (most of the time) it runs well. Some backfiring and rough idle still happens. We tested it with and without a full gas tank. It seemed to run better with a full tank. Are there carburetors available for this trucK?

 

Welcome to FTE! If you scan through the pages of this thread, you should find the information you're looking for as we have documented the necessary procedures for setting up a stock 2 barrel. Is this the carburetor you have? If not, what do you have?

 

It is a two barrel. It was just "rebuilt" by my brother. Also paid for replacement of Power steering pump. It ran better before that.
I was told that a rebuild will not help Where are the other details you mention?
ctechfiles@yahoo.com you may send me any ideas and help you may have

 

See this post on page 3 for a step-by-step procedure for setting up the carburetor's choke, etc. Ignore the first couple paragraphs about the float because that was for something else:

https://www.ford-trucks.com/forums/7...ml#post6422219

Unless a carburetor's casting is broken or there is significant throttle shaft play (which actually can be fixed anyway), there is virtually nothing that a carburetor rebuild can't fix, if the problem is really with the carburetor. I'm not saying you need a carb rebuild; I'm just saying that whoever told you a rebuild can't solve the problems you mentioned was incorrect, assuming the problems are related to the carburetor to begin with.

As for the rough idle\backfiring - could be a vacuum leak or lean condition, both which can be carburetor-related. Backfiring can also be timing related. How'd it run before your brother rebuilt it?

 

ok im going throw my 2 cents in here i had a truck do something simaler what happend is the po put a carb from a auto on my 4 speed he had the vac line in the back of the carb going to the vac modultor on tranny pluged but one day the bolt he had in it came loose i spent a week chasing down problems so check this first save some time lol

 

Once had a similar problem and it was water in btm of carb. Had to pull jets and air bleed screws and your small holes near venturi's. Blow out with a can of compressed air. I didn't see what blew out but it worked. I did see some water in btm of fuel bowl and new it was a problem. Later reassemble and WA LA she ran good. Hate it when you fix something and not really sure what you fixed. But definetly blow out your air bleeds for sure with some kind of carb clean at least when you pull them out. Probably some kind of gremilin in their.

 

Well... Michael, all the information a guy needs to fix his idle has been posted.
It's time for you to do your homework. ;)

If you want/need more details, you'll have to get under the hood and then get
back on here and answer all the questions you've been asked.

"FTEers help those best that help themselves ;)" -just made that up LOL :)

Alvin in AZ
ps- check out Half-Fast Racer's post, it's cool as anything! :)

 

Ok, I know it's been a while but I've been distracted from my project and then I got distracted some more. We just had our second son and he is now 3 weeks old! Back to my project -- last week I found a guy who just happened to have a 2100 carb that he was for sure that worked well. He let me borrow it for a test run. I bolted it on and my problem was fixed. So, now I know for sure it is the carb. During this process I've rebuilt the carb but as I stated previously, but I didn't soak it in grunge eater or anything. Is it worth continuing to try and get the old carb back to spec or will I continually have pesky problems with it? If I eventually decide to replace it with a new one, does anyone have a suggestion? I'm not looking to hot-rod it, I just want it to be a good dependable replacement.

Just in case I haven't said it, you guys are awesome!! Thanks for all the help. All of the advice has been helpful and accurate.

 

Congrats on the latest addition to the family. As far as the carb rebuild goes - to rebuild a carburetor properly, you should soak it in the gallon can of carb cleaner for an hour in three sets - first the throttle body, then the air horn, then the basket full of small metal parts. After soaking a piece for an hour, spray it clean with carb cleaner spray, then use compressed air to blow out internal passages (while wearing goggles of course). This is how a carburetor should be rebuilt - it gaurantees that everything gets completely clean. A lot of people have a tendency to just pop the top off, spray it down with a can of carb cleaner spray, and seal it back up with a rebuild kit - that almost always leads to problems. It's up to you if you want to mess with it or not, but a proper rebuild usually works wonders. About the only permanent damage the old 2 barrel carbs suffer is a mounting ear being broken off the carburetor base, or the throttle shaft wearing out because there are no bushings. A good carburetor rebuild usually costs $50 - figure $20 for a can of carb cleaner, $20 for a good rebuild kit (not the "one size fits all" from discount stores), and $10 for carb spray, a fuel filter, and base gaskets. I don't recommend remanufactured carburetors from the parts store - to this day I have yet to meet someone where that didn't put them on a wild goose chase. It's simpler to rebuild yours yourself, so you know it's done right.

 

Thanks! We've had our hands full lately. I've decided to try and rebuild the carb since I already have everything except for the chem dip. I bought chem dip this evening and will dip it tomorrow. Is there anything critical I should know before I dip it? Are there any hidden rubber parts that can't be replaced?

I noticed two green colored things in the bottom of the bowl that were slotted. They look like screw heads but they look like they are plastic. Do they have to be removed? Can they be removed? Any tips would be greatly appreciated. Maybe I won't melt something vital!

 

Remove all rubber, neoprene, or plastic parts as Chem Dip will eat them up. It'll even eat the gloves off your hand. It's nasty stuff, try not to touch it or get a wiff. I've never been able to get the throttle body or air horn in the gallon can, so I've always had to dump the stuff into a bigger bucket, and work from there.

The slotted items at the bottom of the fuel bowl are jets. They need to be removed so that you can get cleaner down in the main fuel circuit. The jets should be clean too so that there is no varnish in the jet opening. All the jets I have seen have been metal; I've never seen plastic ones but if yours are, you definitely don't want them to touch the chemical. It takes a pretty big flathead screw driver to get them out.

 

LOL! :)
Well... sounds like FMC's "chem dip" suggestion was an extra good one! :)

Those are the main jets and are (were;) brass.
If they are that messed up, that carburetor's had water sitting in it?

I use a screwdriver I specially ground for Ford's large main jets.
Sometimes they are really stuck and need to be hammered down on to
break them loose from their crust. The chem-dip might save you that?

Under that large hollow screw (in the middle) there is a rod and a ball bearing.
The ball bearing is a valve and part of the acceleration pump system.

Look it over read some carburetor theory and understand how it works.
It's not a whole lot more complicated than a toilet. ;)

After cleaning it up and getting it back together you are fixin' to be amazed. ;)

Alvin in AZ