Just picked up my 79 F150, and it was a Colorado truck with emissions and it runs rough. It is now in Minnesota and I'm wondering about how the carb is set up, been from Colorado. Another thing, what size carb would I replace it with? It has a 460 in it.

 

If it has been from a high elevation it is very possible that the carb is just jetted wrong. You wouldn't necessarily need to replace it, just tune it for your location. Contrary to popular belief, the stock carbs often yield better performance and driveability on an otherwise stock motor.

If you're really gonna replace the carb then you really need to replace the intake and then you really need to upgrade the exhaust to get more air out of the engine, etc, etc. I'm not saying there aren't any power gains to be had, just where do you stop? Ask yourself what you intend to do with the truck. If you're gonna drive it, stick with the stock carb. If you're gonna race it, then look elsewhere.

 

2x with Nathan. What's the plan? There is no "magic size" for carb - it all depends how the rig is gonna be used. Will the engine live between 2000 and 4500 RPM? Or will it see more than 4500 RPM on a regular basis?

Second, there is little value to sticking a monster cfm carb on it unless the engine is set up as a system. Sure you'll be able to say, "Yeah, 800 cfm carb on it" but it'll probably run like dog poop unless the engine components are designed and selected to work together to provide the best efficiency in terms of HP and torque within an RPM range.

 

What has it got ? Is it original? My 150 with the 460 came with the holley 4/bl , I can't remember the part number , but its the one that has the idle mixture screws in the base facing the front. I heard they came out in 79 as fomoco's attempt to make it meet emission standards better before they switched over to fuel injection. I don't really know if that's true or not .I have had good luck with mine, allthough i did replace it with a new one about 15 years ago because the new ones were allmost the same cost as getting a rebuilt one.I would just rebuild it and keep it. But what do i know ? Just my $.02 worth.

 

I know a lot of people hate them, but a properly set up and tuned quadrajet is supposed to be hard to beat in terms of power AND economy.

I know a lot of people just rip them off and throw a holley on there, but these same people are usually not much for maintenance or learning how to set something up properly either. Rather than learn how to fix and maintain what they have, they would rather replace it with something simpler and just live with it's share of problems.

 

460 is stock, my plans are to convert it to overdrive, and some day go through engine. What about all the emission junk on it know, my 79 F350 4x4 is converted to a 460 and no emissions, what a night and day difference between the two

 

Early emissions equipment was not the most friendly to horsepower.

 

Should I remove the air pump and the parts that go with it? And should carb be jetted for the alt its at know?

 

Another thing with it, when I slow down it wants to die, its feels like it doesn't down shift all the way. It runs rough both in gear or not but in gear it seems worse. At driving speed its not to bad, but the carb is messed up though.

 

Well I would certainly get somebody who knows carbs to look at it for you and figure out if it is jetted and tuned properly. I knew nothing about carbs when I got my truck and neither does anybody around here so I kinda had to learn. Fortunately mine was jetted properly, it just seriously needed rebuilding. After fiddling with the choke for over a year I think I've finally got it right. You'll also want to make sure the timing is set properly and you have new plugs, wires, cap, rotor, etc. That should help it run a ton better.

As for removing any emissions equipment, for the sake of a public forum discussion, I have no opinion.

 

I know it has new wires and plugs, but every thing else I don't know. I get truck back tonight, driving it home after I bought it and wipers quit. 250 miles from home

 

You know, I have heard the same thing about the Rochester Quadrajet carburetor. The funny thing is, NOBODY I know, including the guys who drive GMs, actually runs a Quadrajet. You will almost always see the so-called famed Quadrajet (Quadrajunk) replaced by a Holley instead. But from my personal experience, GM guys aren't too bright to begin with.

However, I still see plenty of Autolite/Motorcraft carburetors still in service. The 2100/2150 2V and 4100 4V are very good, reliable carburetors that feature annular boosters for better fuel atomization. That means better power AND economy. When I converted to a 4 barrel carb, I switched from a stock Motorcraft 2150 2V to a Holley 4160, and the Holley wasn't near as smooth as the Motorcraft. So I switched to an Autolite 4100 4V and picked up better throttle response AND power! And the best part of all is, I have a FORD carburetor under my Ford!

The Motorcraft 4180 4V (made by Holley for Motorcraft) is also a good carburetor, and should be what your 460 originally came with. These are good emission carbs that also feature annular boosters in the primaries, and are also found on the 1983 - 1985 Mustangs.

 

I could have lived without wipers. I had a tire decide to come apart when I drove mine home.

 

I too have heard them referred to as the Quadrajunk. See the problem is that the carb was too complicated for it's own good. It wasn't fuel injected so none of the fuel injection guys could help and it wasn't your daddy's carb so none of the old school guys could help. Rather than learn they just throw a Holley on it and be done with it. Any of the driveability problems that come from having a (often oversized) Holley are just deemed "acceptable" in the name of performance and getting rid of that Quadrajunk.

You see this all the time with GM guys because the quadrajet came on GM vehicles. If it were a Ford part you would see it the same way. Idiotic performance upgrades, however, are common across all platforms. With fuel injection it's worse now than ever. You can't just throw a new cam and heads and such under a fuel injection system and expect it to work without tuning it. Since people don't want to learn how to tune they buy some new part that's supposed to be a miracle fix. Sure it might "fix" one problem but it creates 12 more. Before long you end up with a complete car full of aftermarket garbage, none of it works as well as stock, and it likely makes less power than stock because the computer doesn't know what the hell is going on. I've seen this on Ford, GM, and Mopar, and don't even get me started on the import crowd!

A friend of mine used to work at a local performance shop that had a dyno. He did the tuning on any of the newer stuff that had a flash PCM, I did any of the stuff that had an ECM that needed a chip. So I've seen my share of working mods, but mostly they were just bad combos that were junk. The worst though has to be this one idiot who brought in a Chevy truck..... Somehow he managed to drive it to the shop and dropped it off. We like to never got it started but we finally got it pulled inside. We looked and we could see that the injectors (throttle body injection) appeared to be locked open. We couldn't believe it was even running. We looked in the floorboard and found the original throttle body, and original injectors. I went for the ECM and found that it only had a 24pin chip instead of a 28 pin. I did a little research and figured it out. This dip**** had taken a throttle body injected v6 truck installed a 454 in it and didn't bother to change the computer at all. He just slapped an aftermarket throttle body in there with huge injectors and called it good. I can't believe it ever started!

We didn't even try. We told him to install a V8 computer with a V8 wiring harness and we'd be happy to try, otherwise get the piece of junk out of the shop. Never saw it again, it's probably rusting in somebody's barn or has had the fuel injection ripped off and had a carb installed where it will get about 2MPG and none of the instruments work.

 

It was snowing and raining with black ice warnings. Three things a 2wd truck hate in the midwest. Also I'm losing all emissions to make this thing run great. Its going to be my somewhat of a daily driver, except for winter, to much salt in MN, this truck is like new, no rust at all. Going to be my sons truck. I was 7 when my dad bought his 79 F350 that's mine know. My boy is know 7 and I got the 79 F150. Best trucks ford has ever built.