'83 Caprice Carb

just a quick question...

i have an '83 caprice with a 305. its time to replace the carb and i noticed on summitracing.com they have two choices. they appear to be the same rebuilt rochester 4 barrel quadrajet style. only difference i can find is the price. one is $300 and one is $386. whats the difference and which one should i get.


here is a link: http://store.summitracing.com/egnsearch.asp?SearchType=Make&N=700+4294908216+4294908194+4294925044+4294925239+ 4294839063+115+4294840138

thanks

just a quick question...

i have an '83 caprice with a 305 and im replacing the carb. on summitracing.com they have two options one is $386 and one is $299. both appear to be the same rebuilt rochester four barrel. can anyone tell me what the difference is? are they the same thing?

thanks:screwy:

Good question. Need more info. Links?

You want a model E4ME carb, not M4ME/M4MC/4MC/4MV. It has to have the "E" on the front, denoting electronic feedback.

i have an '83 caprice with a 305. its time to replace the carb and i noticed on summitracing.com they have two choices. they appear to be the same rebuilt rochester 4 barrel quadrajet style. only difference i can find is the price. one is $300 and one is $386. whats the difference and which one should i get.


here is a link: http://store.summitracing.com/egnsearch.asp?SearchType=Make&N=700+4294908216+4294908194+4294925044+4294925239+ 4294839063+115+4294840138

thanks

Why two threads on the same subject? To answer your question, the more expensive one is the feedback unit that you NEED for that car.

Check your vacuum diagram to make sure you get the right carb. There are a few options. The difference might be between a California car and a 49 state car.

Some of the options area:


California 305 V8
US Federal 305 V8
Canadian 305 V8
Police 350 V8

Good luck.

Correct. With the other, less expensive one, you'd have no place to plug in the the Throttle Positioning Sensor, or the Mixture Contol Solenoid. It you did this, the engine may not run, and if it did run, it wouldnt be good because the computer will then have no way of knowing where your throttle is, and cannot adjust the ignition timing accordingly. You need to get the more expensive one if getting a whole new one unless you convert your engine to being a non CC engine like I did. I personally don't recommend it to others to rid the car of its computer, I just did it because I no longer need the emissions, and the partial hydrogen fuel didn't seem to work well with the computer.

But why spend hundreds of dollars on a new carb if you can simply get a $15 rebuild kit that will bring your old one back to new?

Furthermore, bolting on a "new" or remanufactured carburetor is not likely to solve any problems completely. Any carburetor, especially a new or reman, MUST be adjusted when it is installed. Since you have to adjust the replacement, you might as well save yourself the $300-400 and diagnose/adjust the one you have. Unless you have hit it with a splitting maul or jackhammer, the aluminum really doesn't wear out.

sorry about the double post, i didnt know the first one went through. as far as rebuilding myself vs. buying a rebuilt, i just moved 1000 miles away from home without my dads handy garage outside my backdoor to an apartment in the city where i have no tools and no room to work on my car. so, as crappy as it is im kinda stuck with buying a rebuilt one or going to a mechanic i dont really know and trusting him to rebuild it for me.

thanks for all the help though guys. this forum is awesome!

First of all, THANK YOU for posting ! I had no idea there was a quality name-brand, factory-backed replacement carb for the 80s SBC w/C3 electronic feedback !

I had been looking for one for years, and even personally spoke with an Edelbrock rep about availability of such a unit ("no market" was their reply).

Ok, I'm calm now. You need to make sure all your other (and easy to solve) problems are taken care of before spending all that money on a carb you may not (yet) need.

Check/replace every vacuum hose. If in doubt, go ahead and replace it. They should be flexible and have tight connections.

Next, "try" to re-torque the carb mounting bolts. All those years and all those heat cycles will loosen them up. They don't take much torque (inch-pounds, not foot-pounds), and if they are real loose, you're leaking a lot of vacuum.

Change all your filters (air, PCV, evap canister, fuel). Make sure your air cleaner pre-heat tube is intact.

Now, on the off chance none of that works, and before you actually replace the carb, change the carb-to-intake gasket. Remember to torque and then after a few heat/cool cycles, re-torque until it finally "sets". If the problem still isn't solved, THEN try the new carb.

They are actually adjusted fairly well at the factory, but be sure you can undo any of "your" adjustments. The only ones you need to concentrate on are the idle, and even then you shouldn't require much different from how it comes. You will already have practice in removing the carb to replace the car-to-intake gasket, so the job will definitely go faster the second time around. I've been this route, I know.

Carbs do wear out and get dirty/gummed up with trash over the years. Throttle plate bushings are notorius for wear and cause problems people try to compensate for by "adjusting". It just gets worse and the real problem is never solved. On the plus side is that even if you have to buy the carb, you will already have taken care of all the other stuff while getting ready for he new one.

Again, MANY THANKS for posting the Holley replacement availability ! I gotta get me one.

First of all, THANK YOU for posting ! I had no idea there was a quality name-brand, factory-backed replacement carb for the 80s SBC w/C3 electronic feedback !

I had been looking for one for years, and even personally spoke with an Edelbrock rep about availability of such a unit ("no market" was their reply).

Ok, I'm calm now. You need to make sure all your other (and easy to solve) problems are taken care of before spending all that money on a carb you may not (yet) need.

Check/replace every vacuum hose. If in doubt, go ahead and replace it. They should be flexible and have tight connections.

Next, "try" to re-torque the carb mounting bolts. All those years and all those heat cycles will loosen them up. They don't take much torque (inch-pounds, not foot-pounds), and if they are real loose, you're leaking a lot of vacuum.

Change all your filters (air, PCV, evap canister, fuel). Make sure your air cleaner pre-heat tube is intact.

Now, on the off chance none of that works, and before you actually replace the carb, change the carb-to-intake gasket. Remember to torque and then after a few heat/cool cycles, re-torque until it finally "sets". If the problem still isn't solved, THEN try the new carb.

They are actually adjusted fairly well at the factory, but be sure you can undo any of "your" adjustments. The only ones you need to concentrate on are the idle, and even then you shouldn't require much different from how it comes. You will already have practice in removing the carb to replace the car-to-intake gasket, so the job will definitely go faster the second time around. I've been this route, I know.

Carbs do wear out and get dirty/gummed up with trash over the years. Throttle plate bushings are notorius for wear and cause problems people try to compensate for by "adjusting". It just gets worse and the real problem is never solved. On the plus side is that even if you have to buy the carb, you will already have taken care of all the other stuff while getting ready for he new one.

Again, MANY THANKS for posting the Holley replacement availability ! I gotta get me one.


im taking your advice this weekend. this is my carbs last chance haha

You will need a dwell meter to adjust the M/C solenoid/idle air bleed circuit.

These are pretty cheap, only about $20 or so in most places, even less in some places, and if you have a friend with one you can use it free of charge.

Discarding an otherwise serviceable carburetor because of a worn throttle shaft seems silly when it's so easy to repair the problem:

Remove the throttle plates and shaft, mount the throttle body in a vise, and ream the worn guides straight for a bronze bushing:

http://www.wwdsltd.com/files/4MVThrottleGuideReam.jpg

You only need to bush the two outers, since any leakage at the center is not a problem. Make sure you've reamed deeply enough to accomodate the full bushing length:

http://www.wwdsltd.com/files/4MVThrottleReamDepthCheck.jpg

Clean up your chips and oil the throttle body and bushing. Mount the bushing on the installation driver and drive it flush:

http://www.wwdsltd.com/files/4MVThrottleBushingDriver.jpg

If the bushing is not fully flush, file the end so it is not beyond the throttle body casting. Ream it to the final finish size and to achieve proper shaft alignment:

http://www.wwdsltd.com/files/4MVThrottleBushingFinishReam.jpg

Clean up the chips and assemble the throttle shaft and plates, makign sure the plates are centered in the bores as you tighten their screws.

Easy enough?

thanks blue bowtie. i understand your trying to help me out here. but you obviously didnt read all my posts in here. like i mentioned above, i live in florida now. all of my tools are in indiana. i live in an apartment complex where im not supposed to work on the car in the parking area, and last but not least, im not that experienced with the carbs. in the past ive had all fuel injected cars. sooooooo i appreciate it but it didnt help me at all. however if you know anyone in the orlando area that is a good mechenic i would love to know who they are.

Understood. I read your posts. Since you will need SOME tools to exchange and adjust the replacement carburetor, I presumed you had access to something.

I fully understand the apartment rules thing. I've been there, about a lifetime ago. I was "given the eye" for even installing and charging a new battery in -20ºF weather - until the next morning when about one-fourth of the residents' cars (including the apartment supervisor's) wouldn't start, and they realized I had a booster/charger on rollers. Not likely to happen in Orlando, though.

Good luck with the swap. The remans usually come with the float set fairly close, and the idle air bleed set close enough to get you running. You WILL eventually have to adjust at least the lean stop, idle and TPS, or you will have some problems.

Sorry, I have no clue about shops in centra Florida. I do know a couple guys near the panhandle/Pensacola area, but that's probably not going to help you much. Just to be safe, try to find a shop with ASE certified techs. They'll at least have a better chance of getting it right on the first try, and with the least hassle.