Info on a bad carb.....

1986 Cutty Supreme Brougham, 2D, 307Y, car has 110K actual miles.

I bought the car from basically at an auction, so I don't know the original owner. Carfax.com verified the mileage, as NC emission tests from 1986-2001 verified that this vehicles miles slowly went up. This car has a basically new engine. I don't know how many miles, but am assuming about 50K or less. Engine ran very, very smooth until a few months ago.

After having a local, reputable shop check it out, they've discovered that the carbeurator must be the original and is in bad shape. Since it's the factory Q-jet, it's not a good prognosis. He's looking for a good rebuilt carb but can't find one he'd trust or one that is under $500.

We're considering adding a non-Qjet and using a new ignition system (like MSD). He seems to say that the car's computer will cause problems when a non-Qjet is added, and some new ignition components will be needed to replace the factory ones. I'm not a mechanic, so, a few questions......

1) Holley makes a replacement for the Qjet for my year car. Does this replacement work with the car's computer system like it should? He claims that they are junk and never had success with them.

2) If I decided to go with a non-Qjet (like an Edelbrock universal 550ish or 650ish CFM), would I have to replace some of the computerized ignition components?

Since I am the one driving this thing daily, I'm concerned with gas mileage- I don't want it to get any worse than it is.

If you HAD to replace this carb, what would you do? I would like to give a tweek in the performance dept but I am NOT going to try to run this engine against any Mustang 5.0's, lol.

Thanks!!!

No one can rebuild it?

Did any of the mechanics say exactly what was wrong with the carb.

The one thing that comes to my mind when you say 307 carb'ed is the mixture control solenoid used to always go bad, and the idle load compensator used to go bad.

The mixture control solenoid is the sensor on top of the carb usually with a blue top and two wires it controls the amount of fuel, to keep the engine from loading up.

Usually Quadrajet's did not give problems that could not be repaired unless somebody who did'nt know what they were doing messed with them. About the only time you have to scrap one is when somebody tightens the two front top holddown bolts to tight and warps the top creating a hugh vacume leak, or when the butterfly plate rods wear the body out.

Your mechanic is right they are expensive and holley did take over the reman scene on them which, personally I have never had any problems with the holleys.

Ask your mechanic about the mixture control solenoid. Ask them if they tested it.

hope this helps.

BTW you will want to stay with what the car came on it from factory because of the emission control system, the carbs have jets in them that control the flow of fuel and changing that flow will play hell with the ecm.

Good luck to you. Feel free to PM me with any questions. I typed this out in a hurry so may have missed a detail here and there.

or when the butterfly plate rods wear the body out.

This sounds kinda like what he said. Best I can remember is that he said the plates were not responding as they should. The car won't go into passing gear, normally, unless you hammer the accel pedal twice to the floor. And then, the car ROARS like a pissed off tyrannosauraus (I have a fairly new exhaust system so it's not that!).

This guy is a very reputable mechanic that several people have recommended to me, and he really has done a great job on many other services on my car. He knows J-cars very well. I trust what he's saying for the most part.

I will ask him about the mix-control solenoid.

BTW do the Holley Q-jet replacements function just as the Rochesters? Meaning computer hook-ups and all?

Originally posted by 86Cutty
And then, the car ROARS like a pissed off tyrannosauraus

LOL :D

BTW do the Holley Q-jet replacements function just as the Rochesters? Meaning computer hook-ups and all?

Yes they are remanned and sold by application. Though you still need to eyeball it and make sure it has the same vac ports in the same location and ect.ect.

Thanks- I'll let the mechanic know about the Holley stuff. I think he's wary of Holley b/c he actually owns a Napa-certified autorepair place. Napa apparently doesn't make/reman anything to fit my carb.


Your help is much appreciated!