Does anyone have any experience with converting an old AMC 304 to fuel injection? Have the 304 in my Jeep, and have been thinking about getting a Sniper EFI by Holley or a Howell fuel injection conversion kit. I currently have a 2 barrel carb on it (not sure which one) and it doesn't run the best. It seems real rich at times, hard to get it to idle good, and sometimes hard starting... not to mention the dismal fuel economy. Wondering if one of the fuel injection kits would be solve these problems and be worth doing.
Fuel injection for AMC 304
- Thread starter Oscar11
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My take is that anytime you add a computerized module to a car, you add complexity. A carburetor should run fine if set up properly. Has it ever been rebuilt?
FI requires numerous changes, starting with fuel supply. Are you ready for that? And the total cost?
You might try adjusting the idle mixture screws. Or another carb. A small spreadbore 4 bbl carb and manifold is an easy install and works with what you have.
Or perhaps a quality rebuild of your carb?
You might try adjusting the idle mixture screws. Or another carb. A small spreadbore 4 bbl carb and manifold is an easy install and works with what you have.
Or perhaps a quality rebuild of your carb?
Lotta money to switch, with a bit of work to do it. Swapping a good carb on is likely less work. What is the budget, and what’s your mechanical ability?
Might start with adding an O2 sensor, not saying it is required for tuning a carb but it wouldn’t hurt, and is needed for EFI.
Might start with adding an O2 sensor, not saying it is required for tuning a carb but it wouldn’t hurt, and is needed for EFI.
Assuming you can get a 4 bbl manifold or a sniper that fits the existing manifold and an open spacer the fact it is an AMC doesn't matter. (Quick Google says they had a Motorcraft 2150, so Holley Makes a sniper)
If you can follow instructions you should be able to do a sniper master kit in a day.
If you can follow instructions you should be able to do a sniper master kit in a day.
The carb has not been rebuilt to my knowledge, I might look into doing that.
Both kits mentioned come with everything needed including a high pressure fuel pump, not cheap though. Would probably be $1500 or so depending on which one I went with. Previous owner who built the Jeep said he had tried a 4bbl carb and thought it ran better with the 2 bbl, I might look into rebuilding it.
I'm not a mechanic, but I believe this is within my ability to do. I'm a fairly decent shade tree do-it-yourselfer. Is there a scanner or something that I would be able to hook up to an O2 sensor to read current AFR's?
Yep that's what I'm looking at. It currently has an Edelbrock Performer intake on it, the Sniper should bolt right up
I don't know what carburetor is on that engine or how good it is or it's just smog orientated design but I do know from experience that a properly rebuilt and adjusted factory carburetor can be made to run VERY WELL. IMO you should rebuild the original carb and be very careful about getting all of the adjustments and setting set correctly.
I've done the Howell kit, mind you probably 10 years ago, to a 304, and it was stupid easy, ran well right out of the box, and is still running today. Don't count on the fuel economy being much better though.
OVERKILL
$100 Site Donor 2021
I've used the Holley kit, works great. Easy to install.
I’m not sure, but I do think you can buy an O2 sensor and a gauge… somewhere, never went looking.
Was watching a video the other day, someone zipped a hole into the exhaust pipe and was able to clamp down a bracket that had the required O2 mount. Then use clamps for a no weld instal—usually one has to weld in a bung for the sensor to go into.
You claim you don't know if the carb has been rebuilt. As someone who has rebuilt literally hundreds of carburetors in my lifetime, I would recommend you have the carburetor rebuilt and have it running properly before you decide on any fuel injection kit. A properly tuned carb can run good, start in cold weather with just a single pump of the accelerator pedal (well, maybe two pumps if it's really cold) and have good drivability.
If you still don't think your Jeep is running good on a carb, and after giving it a proper tune up, check into the prices of fuel injection and then decide.
If you still don't think your Jeep is running good on a carb, and after giving it a proper tune up, check into the prices of fuel injection and then decide.
I've done EARLY Holley Pro Jection, Howell, FAST and Holley Sniper. If you're serious about going FI, the Sniper is hard to beat.
First. Set points (if not electronic ignition) then timing to spec. Always set timing with vacuum advance hose disconnected and plugged. Then set idle mixture with vacuum gauge attached achieving highest vacuum possible. See how it runs then. Float in carb may be heavy and/or power valve shot. Before spending big money for fuel injection get the engine running at its best with current configuration. If there’s burnt valves, worn cam, and/or low compression fuel injection won’t help.
gearheadefi.com
I have a friend with a '73 Ford F100. He bought the truck and it ran, but barely. The carb was "rebuilt" by the previous owner and it still ran badly. He tried a cheap rebuild kit, but since someone had been in there before it was hard to see what was worn and what was just incorrectly installed. He ended up buying a brand new carburetor from RockAuto. It was a bolt-on and go solution. Needed a bit of tweaking to get the idle right, but besides that it was way easier than trying to put a fuel injection setup on it.
Fuel injection itself can be very reliable when it comes factory, but those aftermarket kits can be a bit finicky.
Fuel injection itself can be very reliable when it comes factory, but those aftermarket kits can be a bit finicky.
2x on a new carb. Throttle shaft bushings are probably worn and leaking vacuum so erratic idle issues. Many a reman carb come through with leaky throttle shaft bushings. Been there in the past.
Properly adjusted choke and choke pull off it should start fine. Stock carb tuning is a lost art today.
An old 304 is not an economy motor, it was born in the days of 50 cent gas.
Properly adjusted choke and choke pull off it should start fine. Stock carb tuning is a lost art today.
An old 304 is not an economy motor, it was born in the days of 50 cent gas.
LS swap!
390 swap, it's a bolt in. Buddy had a Jeep with a 390 in it. It could pull the fronts off the ground on asphalt.
