hi, i would like to get a new carb for my 85 F-250, its got a 4.9L I6 engine and its a 4x4. the old carb is a run down pos 1barrel carter with a few peices missing. ive just spent the last 3 days trying to rebuild it and i only made it worse. i just want to toss it in the trash and start fresh with an edelbrock or holley carb, ive got an edelbrock carb on my 89 T/A and am extreamly satisfied with it. the problem is i dont see any carbs listed for a 4.9L I6, anyone know what i should do? any help would be greatly appreciated

 

If they are available i would get an adapter plate to go to a 2 barrel and go to edlebrock/carter style carbs, holleys leak pretty easy and it seems like one is always adjusting them things.

 

Unless someone changed it out, your carb is a feedback carb. There should be a plug & wiring harness on the carb & a corrisponding one on the distributor. This system new worked quite well, but now that its rather old, it leaves a bit to be desired. Not only that, but if you're planning on replacing the carb, then with this system you'll need to replace the ignition system as well. This is the perfect oppertunity. There are several systems you can go to, but cheepest/easiest is the earlier duraspark II. You'll find it on just about any truck from about '75-83. Its a stand alone system & as its stock you'll find most parts (except the harness itself) right off the shelf of any parts place. By doing this, you can now use just about any carb that you want. You'd more limited by your intake now. If I may recomend anything, I'd switch to duraspark & a non-feedback carb (earlier) first. Those little carters are easy to find & rebuild, they're in wrecking yards & on e-bay all the time. This way you'd have your truck running quickly & you'll have the chance to save up for a decent offenhouser or clifford intake. You'll want a better intake than the stock for a 2-4bbl. I know there are adapters, but you're motor would still be breathing through a small hole. As for 2-4bbl carbs, I know that a popular one is the holley 390 (4bbl) or the autolite/motorcraft 2100/2150 (2bbl). Some guys do use edlebrocks as well. but I don't know what size. Hope this helps.
Edwin

 

thanks for the reply. well, from what i can see, there isnt any wires going to the carb at all. and the only wire going to the distributor is the one from the ignition coil. ive checked in my haynes manual and id deffinately have to say this is a non-feedback carb, even some of the parts on the non-feedback exploaded view arent on my carb. half of the choke is missing and my first problem was that the rebuild kit i bought for it had the wrong gaskets, so im guessing the stock carb was swapped out for this one. i had to half-*** the carb back together with RTV sealant and im sure that only made it worse. theres also some kind of plate in bettween the carb and intake manifold that has a hose going to the brake booster, there was also no gasket for that in the rebuild kit either....

 

I'd have stopped when I found the wrong gaskets. Usually there is a tag or an ID number on the carb. Your parts man should have known this, and had you supply the numbers.

I bought a 1bbl Carter for a 1975 300 six, and installed it on my 1984 F-150. I left the computer stuff disconnected, as the computer burned (literally) over 15 years ago. Since the timing is not being changed at all, (TFI ignition... no problems, EVER!,) I set it at 8 degrees and let it go. I wish I had done this years ago. The truck runs better than it has in years. No flat spots in the acceleration, and NO gas leaking anymore!!

The rebuilt carb came from O'Reilley's, and I had to go thru 2 rebuilts before I got one that seems to be right.

My tail pipes are finally getting a grey-white coating inside after being jet black for so many years.

 

whats TFI ignition? and how will i know if i have it? and what are the odds of me finding another carb like this one in the junk yards? this one is missing too many peices and id rather not mess with it anymore.

 

The rebuilt 1975 NON-feedback carb only cost about $90. Chances are good that you'd be buying a rebuild kit for the junkyard carb.

Even with the 2 replacements of the carb on my truck, it took less than 30 minutes to do the switch.

TFI? Look at your Haynes manual. The electric connector is a 4-5 wire rectangular connector. From your previous description, I think you dont have TFI.

There are times in Ford repair when it is better to not go the cheap route. Like I said, my '84 has never run better. Have not checked gas mileage, but I know it is running better.

 

one thing that is confuseing me is, was my truck suppost to have a feedback carb? is it possible it was swapped out for an older non-feedback carb? i have no idea if feedback carbs were an option on this engine or stock, and it does mention non-feedback carbs in my haynes manual wich covers 1980 -1990, so im assumeing non-feedback carbs were offered after 1975? also where does the brake booster plug into on your carb? sorry about all the questions, but i am totaly new to ford engines/carbs.

also, i checked the haynes manual for TFI, and i cant find any mention of it. the only thing it talks about is the Duraspark II and III systems. what exactly do the letters TFI mean?

 

AFAIK, your truck came with a feedback carb. Mine came with one, also an air pump, and some hardware on the intake manifold that hooked it to the EGR valve.

Do you have several wire bundles near the carb that hook up to nothing?

My '84 ran for 19 years with the Carter YFA feedback carb in place. The computer died in 1988.

TFI: Thick Film (integrated or ignition--cant remember) In my Ford shop manual, it is referred to as TFI-IV.

Its easy to switch out the distributor from TFI to a regular coil/distributor/points. Ford has not radically changed these blocks in many years. I got an engine recently that is a 1983 300 six that someone changed over to an old distributor w/ points. It was running just fine. A friend put it in his truck, and went crazy with revving and threw a rod, and it continued to run enough to get him back home. Then, the rod came through the block.

People have had alot of problems with the TFI system. Sudden failure with no warning. I believe there is still a lawsuit going. I got a letter trying to get me to join the suit several years ago, but since my truck has over 300,000 miles on the original TFI module (the little box sticking out of the distributor) and have had zero problems with it, I declined.

I've had more problems with DuraSpark II, and III than I ever have had with the TFI.

 

If you adjust them right the first time you shouldn't have to mess with them. I have owned and ran Holleys clear back to the old haystack Holley used on the 55-56 T-Birds. I read about all this trouble with Holley yet I never seem to have any of these troubles.

 

i dont see any bundle of wires "near" the carb, but there is a small power drain somewhere in the electrical system that kills the battery overnight, could that be related to an ignition swap? it could be possible that a relay somewhere from the old system is constantly reciveing power right? i did notice a fairly new bunch of wires comeing out of the firewall that obviously werent stock though. do you happen to know wich trucks/years the non-feedback carb was offered with? and aproximately how much these carbs would cost used? i need to get this truck going this weekend even if it kills me.

 

Go ahead, bite the bullet. Go to the parts store and buy a 1bbl. carter for a 1975 Ford F-150 with a 300 six. Get the one with the electric choke. It will cost you less than $100 TOTAL and will not be the headache that rebuilding a used (and unknown) carb will cause. The electric choke hooks up to switched battery voltage, or the brown wire coming off the alternator. This carb that I suggest will do a good job. Like I said, its the first time that I've seen anything besides BLACK tailpipe soot coming from my truck.

There are many ways to look for a battery drain. Mine was a wire that went to the computer from the solenoid terminal. Figured it out, and have had no problems since... 10 years ago...

Oh yeah, dont ever use RTV sealant on carb gaskets. EVER!

The feedback version of the Carter 1bbl will cost you around $300. I wouldn't.

 

alright, i caved and bought a new carb from my local auto parts store. lucky for me the guy gave me a discount (came to $146 canadian, would have been over 200). much to my surprise NONE of the 5 local junk yards had this carb, or any vehicals under 1990. i installed a see through fuel filter and replaced various other parts. it fired up right away as soon as i saw the gas reach the filter. now, it seems to run great, but theres a sort of ticking sound comeing from somewhere, its not that loud and i cant tell if its comeing from the exhaust/intake manifold or the valve cover. i checked out all the push rods and they all appear to be straight and tight. when im driveing the truck i dont even hear it. could this be just the way the engine sounds? ive noticed if i listen very carefully to the carb on my T/A i can hear a faint ticking sound that sort of sounds simliar.

 

What year carb did you get? Did you get one with or without feedback?

If you got one with feedback, and the computer is dead, you are wasting money.

I drove my non-feedback carb on my '84 back and forth to work yesterday. It needed a good driving.

The non-feedback can be tweeked to give you a good overall performance curve.

You will be glad that you replaced the thing. An old carb can be a real pain.

 

I had a friend who converted to an Offy 4bbl intake and slaped a 2-4 adaptor on his 300, the thing ran awsome.

You should never mix CC systems and NON CC systems. By leaving the feedback distributor on the thing is getting no advance except the initial advance "base timing". This wastes gas and cuts power way down and all that 115HP is needed to move a truck.

I'd suggest you pick up a boneyard carb that fits the system you currently have. Dont bother with the parts store junk carbs they are trash out of the box.