Considering NASCAR ran carburetors up until 2012, I don't know *what* that says about carbs.

Why don't you enlighten us?

 

It says that even antiquated dinosaurs can accept 30 year old technology!

NASCAR doesn't allow any modern upgrades (still require push-rod engines, no boost, etc) and even NASCAR uses EFI now.

Edit: Maybe what it really says is that EFI is now antiquated technology, because even NASCAR allows it.

 

Top fuel is still carbuerated!

 

... and to seriously answer the question.

I agree with everything Lariat 85 said in post #29. If you have emissions testing you don't really have a choice, you need to stick with the EFI.

If not, the BEST solution will be to fix the EFI. If that's not possible, then going to a carb isn't a terrible option. It will rarely be as good overall as a good EFI system, but it can be a lot better than a bad EFI.

If you're sticking with the EFI, make sure you have good ground connections between the battery, the engine block, the frame, the body and any part that has a sensor that's giving you fits. Keep in mind that the computer has no idea what the O2 level is (as an example). It only knows what voltage it's seeing from the O2 sensor. If that reading is out of range the assumption is that the O2 sensor is bad. It might be, or maybe there's a wiring problem that's giving a bad reading. and when there's a wiring problem on a car or truck 95% of the time it's with the ground path.

Once you have the ground taken care of, use quality sensors, and look for corrosion in the connectors. In my opinion "cheap china junk" gets a much worse rap than it should (most of the "good" stuff is made in China too). But there are some companies putting out cheap products that don't work well. And corroded connectors will be the majority of wiring problems that weren't a bad ground.

You can also look over the wiring harnesses. They tend to not cause problems, but if there is any abrasion on the outside, or evidence of overheating (which could have melted insulation), that can cause problems.

Good luck!

 

Nope. Mechanical fuel injection.

 

No emissions to worry about where I am...cats are gone and air pump is bypassed already. I feel like I'm so close but so far away from the EFI being right on this truck. The wiring harness is melted in a few spots and the vacuum lines snap when you look at them...made out of nylon? Why??? I feel like its a combo of vacuum leaks and wiring issues...and I'm not sure I can redo ALL of the wiring. I hate giving up though. Hubby says he can get an adapter plate from PriceMotorsports, already has a carb (a collection of them actually) and an electric fuel pump to lower psi and have it running. It's very tempting because its not just a fun project for me...its a truck I need to go to the feed store and pull my horse trailer. He knows carbs very well,,,nothing about EFI and I bought all the shop manuals and have joined forums and have been reading and diagnosing and learning (first vehicle I've ever worked on) so the stubborn part of me wants to keep going EFI but dang I'm losing every weekend to this truck and I'm terrified to haul my horses with it for fear of breaking down. Sigh.

 

The horses have already left the barn, but if you want a truck with a carb you should buy a truck that shipped with a carb. Trying to retro-fit something like that is just asking for unnecessary headache and expense and unless all the i's get dotted and t's get crossed it might not ever run right.

 

This is probably the most common statement you will hear from the carburetor crowd.

Reality check time. It's been 30 years since EFI showed up and almost that long since vehicles have been regularly equipped with carburetors. Not knowing about EFI is no longer an acceptable excuse.

Changing from EFI to a carburetor guarantees you will be doing your own maintenance and the parts and expertise you will need are in dwindling supply. You will kill the value of your vehicle and you will greatly increase the chances of your vehicle becoming unreliable.

 

It seems to me it would be so much simpler and probably cheaper to sale your current truck and use the money for the efi to carb swap to find you a similar truck thats carbureted. Could probably get something real reliable for under $2800.

 

sorry rubenk, lead head is right. top fuel uses mechanical fuel injection. i used to tune such systems in the late 70s when i was a crew chief. even pro stock has gone EFI these days.

 

You can make a carb intake work on an inline efi head.

That leaves the need for a carb distributor, module and coil. I've actual cobbled together a gm 4 pin module, used stock tfi coil with a duraspark distributor and the thing ran great. Get the fuel psi down and your good to go, make sure the psi is what the carb calls for, they all aren't 7 psi and it can make all the difference, not all carb designs are as forgiving.

Efi vs carb is an old boring conversation, that really boils down to the tune and properly matched components. Efi has been around forever but should you decide to modify the 4.9 to something other than stock, your options all require you spend a lhelluva lot more money than going carb. If you plan to keep it stock I don't see the point in doing the swap.

The only downside to the carb swap on the inline head, is by design, it has a notorious problem with carb icing in low temperatures. There's cheap and easy fixes, though.

If your only issue with your efi is the wiring harness. I have a 4.9 engine harness off a manual 95 truck, I snipped one pigtail off, can't recall which one but its marked and you could splice the one off yours in. The harness is otherwise fine. And for the cost of shipping you can have it. PM if interested.

 

This is a 7.5L 460 I have...1988 F350 Dually AT. Dank Hill....selling it has crossed my mind believe me! I only have 1 sensor left and then the wiring and everything under the hood is nearly new except the computer which we put new capacitors in already.

 

Don't try to de-smog an EFI vehicle. There are zero benefits to doing so and you WILL cause running problems. If vacuum lines are breaking, replace them all. If wires are melted, replace/repair them. Don't blame EFI for issues that would cause ANY engine to run poorly.

 

Not really.

http://www.tweecer.com/

Base unit costs about what a good entry level carb does, top shelf version costs less than most Holley 670s do even on discount.

 

De-smog is a complete waste of time.

But doing so will cause zero running issues.

If any negative issues are experienced, other than a CEL indicating the EVP and two solenoids are missing, then theres problems unrelated going on elsewhere.

I've either removed faulty systems or left them delete on builds and experienced no issues, for years. But I would still not recommend it be done, nothing to gain, next buyer might not be so gun-ho about it.