Quadrajet or ???

I have a 71 351 Cleavland with 51,000 original miles on it and I want to replace the original quadrajet. I had it rebuilt but the car won't run for more than a few minutes and then stalls. It's hard to start back up and if you try and move it that's almost impossible.

The old card did well until it sat for almost a two years and the fuel went bad. It did a number on the carb and now it isn't worth a darn. My big question is I want to replace it with a newer style carb but I'm really not sure on which one to get. I don't want to replace the intake just yet so it will have to go in place of the oem one and still allow for the other stuff to hook up to it.

I really don't know much about Ford's so any help would be great. What will I need to get it all hooked back up so it looks original again.

Thanks again.

The rebuild was done as a favor by a real mechanic but something else must be wrong with it. Maybe he didn't get it cleaned enough. I really don't know. He said that there aren't any manual adjustments that can be made to it while it's on the car. :-/

I am way more familiar with Holley's than the Q-jet. They (Q's) are supposed to be a good carb once adjusted. I don't believe that there are no external adjustments though. Idle speed, and air/fuel idle mixture should be able to be adjusted "externally". You can get a "spread bore" Holley as a replacement that will bolt on very easily...If you could post some pictures of what you are working on, we might be able to spot something obvious for you...

Quadrajunks are a picky carb , have rebuilt many over the years ,some worked great and some i have spent weeks on trying to get right ( and they never worked right )and when you run into that problem with them i found it best to chunk it in the trash and buy a Holley

Ya could be more...But i would find a carb to test her out on if you can...Does your machanic have a carb you can test on yours?...lol......Btw what cleveland is she?.And what carb? 4300? 4300d? cause if she is a spread bore you cant fit a standerd elder or holley on top...Them speadbores are just too wide on the manifold and leave big gaps...I know from having one on mine and i had to replace the manifold and carb...i put the carb in a box..matching spreadbore 4300d's bring a good chunk of change.

Btw..I like quadjets....There was nothing wrong with mine..It turned out too be something in the motor...They get good gas milage when your being easy on them...And they got huge secondaires......I just drove my cousins 74 trans am this weekend...has a 504 hp 465ci ponitac with a 850 quadjet on top...Its a beast ..He had it rebuild by one of the best quadjet guys in my area....and they went tested on dyno...They did it first with his 850 old quad...504hp and 510 tq....They pulled it off...And the shop put on a double pumper demon carb...It got 510 hp...tq dropped too 504.....The shop was very impressed with how well it did against a full race carb..They said wow..Who ever rebuild this..New what they was doing...lol

Have you flushed out the old fuel? If it's the original tank you probably have a lot of sediment and rust particles in it. You may want to temporarily put on a clear glass fuel filter and see what is being pumped to the carb. I would do this first before investing in another carb and you may still have problems. If original tank I would strongly recommend putting on a new one and flushing out the fuel lines.

I would go with a holley carb, or better yet a proform / quickfuel. I wouldn't use a quadrajet on anything. If you want to go this route without breaking the bank on a manifold I have an edelbrock performer 2v manifold available for $50 that uses a square bore carburetor.

Remove the line going to the fuel pump and then run a line from a can with fresh fuel to the pump and see if it runs then. This will eliminate the tank/lines and point you in the right direction.

Remove the line going to the fuel pump and then run a line from a can with fresh fuel to the pump and see if it runs then. This will eliminate the tank/lines and point you in the right direction.

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Second...and pretty easy to do. This way you can eliminate fuel as an issue. You can also make sure your fuel pump is putting out....nothing more irritating than a dry pump.

Wow guys thanks for the replies. I will get some numbers off the motor and carb and post those. I'll get some pics too.

I removed the tank and flushed and cleaned it really good. It did have some rust in it so that could be causing it. I will look into getting a new tank to be for sure. The one thing I didn't do was flush the line before putting it back together. I did have to replace the fuel pump because it quit all together.

I do know that the motor ran very well and super strong before the gas went bad and gunked the carb up.

Well, I will try and get these posted soon. Thanks.

Wow guys thanks for the replies. I will get some numbers off the motor and carb and post those. I'll get some pics too.

I removed the tank and flushed and cleaned it really good. It did have some rust in it so that could be causing it. I will look into getting a new tank to be for sure. The one thing I didn't do was flush the line before putting it back together. I did have to replace the fuel pump because it quit all together.

I do know that the motor ran very well and super strong before the gas went bad and gunked the carb up.

Well, I will try and get these posted soon. Thanks.

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Hopefully thats it...Check the fuel filter too...They get so plugged..Wont let enough gas threw...Sounds like bad gas and crud..lol

So if crud is causing it what about what's in the carb? Won't that cause some issues or will it work itself out?

So if crud is causing it what about what's in the carb? Won't that cause some issues or will it work itself out?

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Well...counts if anything got past your fuel filter..You got a fuel filter on it right?..I would check if its clogged .... I just fired up a car that has been sitting for 15 years...with bad gas in it..Unhooked the fuel and ran my own strait into it..Most carbs even when full of slag will clean up enough too run...Maybe not perfict..But run even with dirt issues....Cause usualy if the floats and stuff get stuck they shoot gas all over the place to tell you they are plugged.

Here is the little mustang 2 i hooked a burp tank too...I made it out of a used radiator fluid jug....And i sat it away from the car incase of fire on its own stand and made sure there was zero leaks..This cars carb even had leaves and dirt packed around it...Runs like a champ...lol..I didnt do anything put shoot a little starting fluid in it...and tapped around the float bowls with a rubber hammer lightly to break loose the floats...You will notice my burp tank sitting up high ...gravity force feeding the carb.

If you need to replace the carb, go with a Holley.

My '71 M-code runs a Holley (80670).

Soon to run a Holley 86770.

mike

The funny thing is before I got the car it sat for 10 years before and I primed it and got the thing to run like a tiger. Then after 1 1/2years the fuel goes bad and craps everything out. I bet the fuel tank is causing the issues.

So I was looking on Ebay for a tank and came across the spectra brand tanks and then the other makers. Which one should I go with? what's so special about the Spectra tank? Has anyone used the other brands?

Here is the infor from the door on the car.

Warranty Number: 1F05M18094

Year: 1 1971

Plant: F Dearborn, MI

Body Series: 05 SportsRoof, Mach 1

Engine: M 351 4v V8

Unit: 18094 18094

Miscellaneous Vehicle Data

Body: 63R SportsRoof, Mach 1

Color: A Black

Trim: 5A Black All Vinyl, Mach 1 Luxury

Date: 19/71 code not found

D.S.O: 53 Kansas City

Axle: 6 3.00:1, Conventional

Trans: U C6 Automatic

When you do get it running,check for vacuum leaks around the manifold. I assume you cleaned those plugs up well and checked to see if they are wet or dry after turning it over a few times.Also this crap gas they sell these days is hard on rubber and plastic,the ethanol dries things up over time. the guy at the speed shop told me that when fuel went to 10% ethanol a few years back he started to recieve a rash of calls from people with higher compression motors,they all started burning VP in their fuel.my car will burn the 93 but starts hard, when i add the vp it fires right up. it's a long haul to get the vp for me,and i am going thru the same thing you are, I've re-jetted and up springed my edelbrock. new pump, hotter and colder plugs, different dizzy' cam advance,etc. its a jeckyl and hyde motor.one day it turns right over, the next hard starting. I'm leaning toward a muti-spark CD ignition system next, if no dice with that i'm going to look at my cam and check for drift,maybe even throw in a stock cam to ease my mind.

All it takes is one little tiny piece of build up or sludge to dislodge somewhere and clog up a venturi in the carb. Especially, with a Quadrajet(junk). Plus there a 150 different little parts inside those carbs and they are very difficult to rebuild right. Not that it can't be done, but it's not for the novice.

I'd toss that thing in the garbage can(where those Rochesters feel most comfortable)and go pick up a nice Holley 650cfm for that thing. Vacuum secondary of you are more concerned with just cruising, but still want better performance, or mechanical secondary if you like to romp on it.

May take some jetting to get it dialed, but once it's tuned, you will be stoked! If you do go for the Holley, which I highly recommend, I'd be happy to give you some Holley set up's, jet's nozzles, etc, that will get you real close to being dialed.

I will keep that in mind. Im going to replace the tank and see what that does. If I replace the carb Id like to keep the factory breather, plus Im going to get ram air for it and want to keep it stock.

All it takes is one little tiny piece of build up or sludge to dislodge somewhere and clog up a venturi in the carb. Especially, with a Quadrajet(junk). Plus there a 150 different little parts inside those carbs and they are very difficult to rebuild right. Not that it can't be done, but it's not for the novice.

I'd toss that thing in the garbage can(where those Rochesters feel most comfortable)and go pick up a nice Holley 650cfm for that thing.

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My word.. Dont toss it in the gargbage!! hehe..Those carbs "specialy matching year" Cant be worth a mint..All the high preformance quad jets are big bank hank now...Cause everyone did throw them away....Atleast put it up for sale if you do that...lol...Or put it in a box and send it too me please...lol..ill pay for the shipping even..lol...Ill stand up for quad jets....they kick arse........Send them all too me..Ill take everyone anyone sends me...But ill tell you right away...You shouldnt....Cause they are worth more than your whole motor in value sometimes...lol...Autolite 4300D series which has a spreadbore design, small primaries and oversized secondaries fetches upwards to $2500-$4000.00