creepingdeath

So today (shitty day) i swapped carbs becuase im sick of trying to play around with my current one. I have an 84 q-jet and a 74 q-jet. When i put the 74 on and tried to start my car it ran for about 5 seconds and sounded really weird (like a honda or something) so i tried again and gas started bubbling out of the top and going everywhere so i played around with it for a bit and treid again same thing. So i siad screw it and put my 84 back on after tearing it apart and cleaning it. I put it on the car and the car ran good but the idle was a little high so i went under the hood and tuned it until the idle was good. The all of a sudden i start hearing this weird splashing noise and my arm slipped off something, my dam radiator hose fell off from leaning on it and i got completley covered in coolant fluid. so now my car is parked for awhile haha. Does anyone know why my 74 would be bubbling/spraying out fuel from the top? is something broken?

InfernalVortex

iTrader: (4)

Is yours a Computer Controled QJet? If so then that's the reason teh 74 Q-jet aint workin.

creepingdeath

Ya it is cc but i was told if you just unplug it it will work fine? what do i need to do to get my 74 to work?

327_TPI_77_Maro

iTrader: (8)

A lot of things won't work fine on a CCC car, without the CCC working. Like engine timing, TC lockup, important things. You need a CCC carb.

afida15

why dont you just go get you a junk yard HEI distributor or get a summit one there pretty cheap and wire up your tourque converter lock up switch, i think ive read theres a way to do it, just do a search.

creepingdeath

Well whats the benifit of having a CCC?? Better fuel mileage?

afida15

i really dont know the advantages of CC carb but if it was my car i would just go with the non cc one to make things a whole lot simpiliar

327_TPI_77_Maro

iTrader: (8)

CCC carb allows much tighter control over emissions on the primary circuit. This also should translate into better fuel economy at part throttle cruise

naf

iTrader: (7)

Yes the ccc-system will generally provide better fuel economy with no loss of power compared to a mechanical q-jet. Your '74 carb probably had a stuck open needle/seat, bad float, whatever. Had it been sitting around for a while before you tried it?

The CCC-Qjet, when working properly, is also self-adjusting to a point and will be easier to tune for most engine/power modifications, within reasonable limits of course. In this respect I consider it simpler than the mechanical version which may require jet and/or rod changes to tune.

creepingdeath

ya the non-cc q-jet has been sitting for about 2 years but it was on my last camaro and it ran very very good. I could start the car in -30 weather without plugging it in and it ran beautifully. Im going to be tearing the car apart this spring for and overhaul so i think im going to switch to non HEI holley 670 SA

Sonix

iTrader: (1)

Don't bother with the cc-qjet in my opinion. My car had one, but a few of the soft parts were broken. These are unheard of in salvage yards and napa doesn't carry parts for it. They told me I was lying when I said I had a "computer controlled carburetor" ----
Napa: "Yea, it's called throttle-body injection buddy" ----
Ne: "no, no it's not...sigh...."

Many parts don't exist in the aftermarket as well. eg. I dropped and lost a primary rod, the goofy one with a spring on it? I couldn't get a new one so I went non-cc and haven't looked back. You have a stick shift so there isn't a lot stopping you. You'd just need to get a JY distributor to go along with it.

Don't bother with a smaller holley vacuum secondary carb, that's a downgrade. Plus you'd need to get a square bore intake manifold to match it (IIRC).

z282slo

I'm going to sound like a jerk .....but here goes, DON'T EVER CALL A Q'JET SHI**Y AGAIN!!! But really get cliff ruggles book on Q-jets, spend a saturday morning collecting parts at the j-yard, find un carblike economy, great power and the envy of your friends. Good luck!

creepingdeath

They are good carbs, but holleys or demons are way nicer, perform better and simpler to use..

327_TPI_77_Maro

iTrader: (8)

When Qjets don't work right, they deserve their reputation. A malfunctioning Qjet will nearly get you killed trying to cross traffic. It's not always as easy as just rebuilding. I have spent years working on the non CC carbs and a few on the CC stuff, and have tons of parts carbs, the Doug roe book, etc. They are not easy to work on. My CCC setup calibrates as spot on per the computer dwell readings but still runs junky. It's almost like you have to buy a CCC car that already runs right, or avoid them like the plague. They are hit or miss from what I have seen

clm2112

iTrader: (1)

Welp...I gave my last Q-Jet away a few weeks ago...to the same fellow who is getting my old 350 for use in his boat...he needed some choke parts, so he just got the entire carb to play with. I doubt that I will ever have another pass through my hands.

I have only one real issue with the Q-Jet...availablility. The support for it just isn't there, whereas everybody makes Holley-Clones and you can get darn near any part you want/need (Except that elusive "Quarter-Mile Dial" kit...not that I really need it, but I would like one just to play with )

But when it comes to a Q-Jet, you can get a remanufactured one (and it's probably screwed up too) or search the U-Pull-It yards for suitable rebuild canidates, track down rebuild parts, and spend a heck of a lot of time on it. There was a time when the Q-Jet was the best bang-for-the-buck carb, but that time has passed.

Sonix

iTrader: (1)

That's different from a malfunctioning holley/edelbrock/other how?

Q-jet parts are in every scrapyard for free, and Edelbrock makes a bunch of the parts as well. Also, every parts store in north america carries a rebuild kit over the counter, whereas Holley parts you need to hit up a speed shop. My local Canadian tire/Parts source/Napa has a q-jet rebuild kit (like autozone and pep boys I'd guess).

I will agree that they are kinda annoying to rebuild. Take the whole air horn off to do anything? And fitting the power piston later? argh! I'd guess a holley is easier somehow, but i've never tinkered with one so...

327_TPI_77_Maro

iTrader: (8)

It's different because it's nearly impossible to make a Holley too lean to run right. The air bleeds are set up super fat on purpose, so people who don't know what they are doing can not possibly burn up their engines by accidentally making the mixture too lean. Holleys are huge fuel wasters, but being too rich all the time does ensure they usually are good enough to drive on without major malfunctions.

Big difference from the Qjet, which is very easy to be super lean and not run right, because they were designed to try to target very narrow stoich AFRs

scooter500

iTrader: (1)

for a too lean condition on ccc carb... is that being caused by the o2 sensor? the computers getting signal from the o2 but maybe it's the o2 sensor itself?

creepingdeath

My car doesnt have a 02 sensor.. but there is one small wire that goes to the fire wall from the carb and i couldnt trace it any further. Im going to get a holley
I'm a reletive novice and everyone uses them even the edelbrock family I want a street avenger but I've heard the Dp's are better.

naf

iTrader: (7)

Creeping: Your one small wire is likely the choke heater wire. You may want to verify this as you can use this same wire for an electric choke on another carb you may swap over.

Scooter: 327's issues, while they may not be universally unique, are definitely not normal. He has some valid points and I agree that the ccc-qjet system is set up with emissions AND mileage as primary goals. The ecm commands a stoich mixture and there's no way to tune around this. As such the idle is maintained just a hair on the good side of lean and this can cause a bit of a hunt at idle that would normally be 'tuned' out in a mechanical carb-any mechanical carb. The system IS designed however to fail rich. Most normal failures, vacuum leak, sensor bad, etc. will cause a rich condition which is 'engine safe'.

As for the mechanical q-jet, I agree with Sonix, 'course I rebuilt my first one in 1981 on a '76 camaro. Didn't have the $ for anything else then and have gotten pretty used to them since.

creepingdeath

[QUOTE=naf;3600705]Creeping: Your one small wire is likely the choke heater wire. You may want to verify this as you can use this same wire for an electric choke on another carb you may swap over.

Is that the only diffrence cc carbs have is electric choke heater?? Thats the only wire coming out of my carb. I thought cc carbs were linked to the distributor or part of your ignition.

327_TPI_77_Maro

iTrader: (8)

Nooooooooooooooooo... the CCC has nothing to do with the choke heater. The mixture control solenoid gets a 2 pin plug on the top of the carb.

naf

iTrader: (7)

Many Canadian models did not come with the CCC-Qjet and instead got a mechanical qjet. The only wire connection to most mechanicals would be the choke heater wire. I say 'most' because some mechanical carbs will come with a cold enrichment solenoid that has a connection that looks similar to the ccc-qjet mixture solenoid connector (MCS). It provides additional booster shot during cold warm-ups.

You can identify a ccc-qjet by the two-wire connector for the MCS on top AND the three-wire connector for the Throttle Position Sensor, front left.

creepingdeath

Then i dont have a cc carb!! why doesnt my mechanical carb work!!?? it was working beautifully in my 82 and now fuel bubbles out of the top... I read how to tune them and tried everything i could with no luck, and once i put the newer q-jet on it worked fine... could something be broken?

Sonix

iTrader: (1)

Rebuild it and find out!!!!

creepingdeath

Is a rebuild worth it? also i know barely anything about carbs...

five7kid

iTrader: (14)

Fuel bubbling out of the top 99% of the time is crud in the float needle/seat.

Rebuilding is a great way to learn about the carb. The carb kit will have instructions that take you through the process step-by-step. You'll see what the pieces are, and with a little research (based on what the stuff is called), learn what they do.

There are two things that make a q-jet not worth rebuilding: 1) Warped/cracked airhorn from some ham-fist that tried to take it apart before and didn't see those two screws under the choke butterfly and tried to pry the airhorn off anyway, or said h-f tightened the airhorn screws as hard as they could when they put it back together; or 2) a carb that has sat with water in it and the internal passages are corroded to the point of being FUBAR.

Worn throttle shafts could be added to that list, but that is repairable.

creepingdeath

Thanks five7kid, maybe i will rebuild it. Ive taken the carb completley apart once and i didnt find it difficult but, im thinking of sending it to the "Carb shop" www.customcarbs.com They have a form you can fill out online and they can custom tailor your carb exactly to your car without even seeing it. and they specialize in rochesters. Not sure how much it would cost but it sounds like it would be worth it, plus it would only take a couple of days.

Street Lethal

iTrader: (16)

^ There are plenty of people out there who have taken their CC quadrajet's to the very next level. Fuel rails, weld in some bungs for some injectors, and, well....

Sonix

iTrader: (1)

What on earth IS THAT street lethal??? A carb sans fuel?? So.... it's just like a butterfly, like a throttle body? Not sure why anyone would do that...

creeping, apparently there's a q-jet shop in Stony Plain. I can't remember the web site now, but it was something like Carb shop, or something similar to that. Not sure if they still exist.

A $40 rebuild kit will get it done. If you've ever built a little model car as a kid, this is the same deal. A bunch of small parts, remember where they go, plus you've got instructions to follow, etc.... No big deal.

Street Lethal

iTrader: (16)

^ I was actually going to purchase that car at one point in time, it's an 80's Buick Regal with a bored out 70's 455 Buford engine. The stock '86 CC-Quadrajet was heavily modified; completely gutted, primary venturies removed, Idle Air Valve removed, all unnecessary openings filled, removed secondary valve, metering rods, smoothed the bores. Primary/secondary throttle linkage normal, retained TPS, retained throttle kicker solenoid to kick up the RPM when the A/C is on, all controlled by a MegaSquirt ECU.

robertg

iTrader: (2)

any idea how the mods were done? i'd like to know more about this setup.

thanks!

creepingdeath

That looks kinda queer, is it functional?

Silver87

Sweet

creepingdeath

haha sorry i quickly looked at it not realizing what it was... I see what it is now but why would you want to make a carb run like mpfi? haha i can't even begin to understand how that works...

Sonix

iTrader: (1)

I thought that distributor in the front looked funny, Buick engine I was thinking.
What an oddball setup, I can't understand the reasoning behind why you'd do that, but hey, that's probably why it's the first one of... "those" that i've ever seen.

Creeping - how's the car running right now, or is it parked? Any luck on rebuilding it? It's really not that hard, once you've done it once, it sure seems easier after.