My carb is crap. Theres a bunch of vaccum lines broken off and just doesnt run right. I've tried to fix it and rebuild it but i would just rather replace it. I have a 305 LG4 completely stock. What carb would be a good replacement for the Qjet?? I'm looking for something with a little more airflow because i would like to put an intake and cam in when i junk the Qjet. Any suggestions on packages or brands?? Any help would be great.

Everybody has a different preference for carbs. Any 600 CFM carb will run fine on a 305, set up properly.

A double pump holley will be fine since you have a stick. I would not put a DP holley on a small CI automatic, since it will bog out the low end really bad. On your car it will be fine. A VS would also be okay but the DP on a stick is going to be more responsive.

A Holley will probably get 50-75% of the gas mileage of your Qjet. They are intentionally jetted and air-bleed-ed really fat out of the box.

You don't have an airflow issue. Q-jets flow a lot more than your 305 will need in streetable form.

I see you have a T5, but that doesn't automatically disqualify the q-jet. If you go aftermarket, stay far, far away from Performer and vacuum secondary carbs - you might as well stick with the q-jet rather than putting one of those on.

Putting a double pumper on a small displacement engine is all about sizing the carb according to displacement and minimum RPMs when going to WOT - which are combo choice things, that's all. There is nothing fundamentally wrong with a DP on a small displacement engine.

Putting on an aftermarket carb requires replacing the distributor as well.

i know i dont have an airflow issue. why does it require replacing the distributor?? Any brands of carbs that you guys think are the best?? I was planning on getting a dp just because i plan i doing motor work in the future but i wasnt going to go to big on the carb.. just around 600cfm-650cfm.

Becasue your Q-jet is computer controlled (hence the TPS and Mixture Solenoid). Your dist. is computer controlled as well. When you disconnect the CC carb the ECM is going to be put into limp mode which isnt going to adjust timing and advance accordingly. You will need at least a vaccum advance dist. Back when my '86 had the LG4 305, I pulled all the emissions, put a Performer intake, Headers, an older non-CC Q-jet and a Vaccum-advance dist. I bought from Summit. It worked out well. The dist was only $150ish at that time. But that was also 1998ish. You could do a full MSD setup, but that will cost quite a bit more. BTW, the Q-Jets arent junk. They are actually a well made carb. Rebuilding them isnt for the novice, but isnt hard either. I read a few books, rebuilt a donor...it worked great, then rebuilt my stock one...it worked great and then rebuilt the non-CC one I got...it worked great. Futermore, I dont think that complaining about broken vaccum lines on a car that is 21 years old and a carb thats probably the same age is grounds for calling them junk. A 21 year old car is going to need more care than a 5 year old one. Rubber and gaskets dont last 4-ever

The stock distributor does not control timing. The ECM does that, and it needs the throttle position data from the carb. Now, you can get around that (see my thread about doing what can't be done), but you can't just take the stock carb off and put on a Holley, Demon, or Edelbrock. You either need to do what I documented in that thread, or get a vacuum/mechanical advance distributor.

A 650 Holley DP would support a 350 in the future without killing you on the 305. But, it is bigger than the 305 needs. A 600 would be too small on anything but a very mild 350.

I run Q-jet on a 350 with a blower pumping out 8-10 lbs of boost, and yes it is a CC Q-jet. I have to say, the Q-jet gives 20-21 MPG highway and does so while making near 500 Hp...

If you move away from the Q you will ahve to essentially remove your computer, change the Distributer, at the least. I have done this chore on a 307 Olds engine with a large cam and head work. To be honest it is not worth the effort. Find a good carb shop and pay them to build you a Q-jet. you will be happier.

If you plan a 350 in the future it's as easy as putting it in, re-tuning the carb and changing the Prom in the Computer.

My car came as a rolling chassis to me and was setup for an edlebrock. First thing im doing is buying a new wiring harness and putting the cc-q-jet back ON! I love the fuel mileage that my 83 firebird got. Mod the exhaust and they will move great.

I don't know about a 140 horsepower LG4 with just an exhaust "moving great" (16 second 1/4 mile LOL) but it will be something...

heck I pulled my cc-qjet off and went to mechanical qjet, and adjustable vacuum advance dizzy and on a recent 600 mile round trip I still got 22, almost 23 mpg, so had the cc-qjet been on it and properly operating I could have easily gotten 25mpg, and all this is with T5 and 3.73 gears.

I love qjet, actually got rid of my 600 edelbrock after I got my mechanical qjet.

Seeing as i dont have a lot of cash....horsepower is on back burner for now.
http://www.thirdgen.org/1985-pontiac-firebird
read that again please!
155@4200 hp
245@2000 tq

and thats BEFORE MODS!
yah shes no road monster but at least i drive a trans am and not a civic LOL! 25 mpg and its american made....im HAPPY as hell with my car. to gm.

Who was it that just had an article on tuning the Qjet?

I think it was CHP with their "****** Mobile" or whatever it is they call their project '83. I'll try to find it.

Edit: Why in the name of the Camaro is mu||et censored? It's part of the culture of these cars!

wait....wtf????? im lost in what your talking about.......

Ahh, the name of Chevy High Performance's Thirdgen is Mul|etov Cocktail. And instead of putting on a new carb they just had the Qjet on it tuned. Four page article on it in this month's issue.

And this website censors the word Mu||et. For a reason I am lost on.

X2!!!


My 87 Olds 442 (olds 307) had this done to it by a previous owner... He put the original "Quadra Junk" in the trunk and never got around to throwing it out... Lucky for me he never got the e'brock carb to work worth a damn... It was impossible to start, impossible to drive and seemed to have more bog then a peat farm...

As a result he sold the car to me for a song... Also lucky for me he did not cut the harness, he just tucked it out of the way...

$5 worth of Vac hose
$25 rebuild kit
$35 TPS senor and a
$20 vac pull off

So about $85 worth of parts and I had restored the Q-junk and the car ran like new, no bog, starts great, idles great and hauls a$$...

I gave the e'broken to a neighbor of mine who thought I was nuts... Guess what. He couldn't get the e'broken to work either... I think he sold it for $50 on the 'bay.

I recently had to get a new carb to to the fuel filter inlet stripping really bad, I stuck with the q-jet, but I got the one remanufactured by holley, I love it and my car has better acceleration from it. I would def. stick with the stocker.

I'm just going to find another Q-jet after all.. Thanks for the help.

Q-Jets are wonderful if they're in good working order. 20+ years of heat/ cold cycles will damage anything and vacuum lines are cheap.

Look for an electronic Q-Jet off a low mileage Chevy 305ci Camaro, Monte Carlo, El Camino, Caprice, or Pontiac Firebird, Grand Prix 305ci. Try to get one off a Monte Carlo SS if you can. They're pretty common and have slightly richer metering rods. Make sure that it hasn't been rained on or had people bang it up. This'll work until you learn more about tuning your Q-jet. While your at it, If you find a Monte SS, grab its air-cleaner assembly, it'll give you some more airflow to your carb. Keep your eyes open for a dual snorkel system off a Camaro Z-28 HO 5.0 liter aka L69 305ci. They're getting rare and pricey, but you might get lucky. I did!

Try to find an '86, '87, or '88 if you can. If I remember right, the early versions of it don't have all of the vacuum ports you need. I'm not sure of the exact year of the change in design, I think it was '84 but it could've been '85. Look in the Chilton or Hayes Manuals for the vacuum line diagrams and count the ports connected to the carb itself, that will give you the answer.

Make sure its off of a Chevy 305 and not an Olds 307 or you'll have some problems. Buy yourself some carb cleaner, spray the livin crap out of it until all the gunk is off of it and be careful not to spray any into the electrical connetions. Good Luck!

I know of a complete CC q-jet system that will be available soon. . .

This guys got a CC-Qjet going in the mail today. ;-)

I am also looking for an unmolested CCC Qjet that has not had any of the tamper proof parts removed

See my post above: There's still quite a few around, but now that scrap metal is at an all time high....EVERY boneyard around here is crushing cars as fast as they come in. I've thought about hoarding some E-Q-Jets, ECMs and PROMS for the future. They're gonna be hard to find in a few more years. A/C delco is dead 'cuz GM sold off the division. It's now Delphi and they dumped lots of parts @ auction during bankruptcy. Good luck finding LG4/ L69 sensors. The costs have soared and most are not in stock. I had to wait for almost a month for a new thermostat sensor. That was last summer tho.

I had to buy all new sensors and had no problem at NAPA and Advance. $10-15 each

what sensors are you guys talking about

I gotta dig up the list I made, I'll post it as soon as I can find it.

rofl....sensors? Q-jet? what next? stock manifolds?

i think he was talking about the engine sensors, not that the q jet had some, lol

I hope anyone would realize he was talking about the intake manifold temp sensors and such, but apparently some people are in outer space.

I just purchased a boat with a non cc Q jet. After a good rebuild and attaching the choke rod which was MIA she runs awesome. I at first had a harder time starting when hot and cold with 4 turns out on the screws but since taking them back in 1.5 to 2.5 out it starts up alot faster and no more gassy smell.

327_TPI_77_Maro: Thanks for the back up on that one.
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I'm still hunting down my list, sorry. All of my belongings are stacked in piles right now. My landlord had to do some renovations & everythings kinda helter skelter. I should have that parts list early next week. There's a few sensors that are used on stock LG4's.
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If you don't use CCC Q-Jets or care about them, you had better not use the stock distributor or need to pass a smog test. Besides, I knock down pretty good gas mileage with the stock system in place. Ripping it off will only give you marginal horsepower increases, if any, unless you upgrade your heads, etc. One huge benefit to the CCC Q-Jet is that it tries to maintain the magical 14:7:1 air/fuel ratio and keeps the engine outta detonation. Countless carb tuners have tried to achieve that perfect ratio for as long as there's been carbs. This often mis-understood system does that all day long. It's a lack of upkeep, proper service and age/ mileage that causes these Q-Jet's bad reputation. Most are pretty tired if they havn't been rebuilt. Many were screwed with by the local shadetree mechanics or teenage newBs. When I was in high school, these cars were all over the used car lots. I laughed at the kids who had 80's Monte/Grand Prix 305's, Olds & Regal 307's, carb'd F-body's,' cause few of them seemed to run right. "Common Knowledge" was to cut & plug off the vacuum lines, disconnect the electronic junk, pull the smog pump & AC, and run it! God, I remember seeing these cars going for dirt cheap due to "Carb problems". Wish I had some more insight then.

327_TPI_77_Maro: Thanks for the back up on that one.
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I'm still hunting down my list, sorry. All of my belongings are stacked in piles right now. My landlord had to do some renovations & everythings kinda helter skelter. I should have that parts list early next week. There's a few sensors that are used on stock LG4's.
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If you don't use CCC Q-Jets or care about them, you had better not use the stock distributor or need to pass a smog test. Besides, I knock down pretty good gas mileage with the stock system in place. Ripping it off will only give you marginal horsepower increases, if any, unless you upgrade your heads, etc. One huge benefit to the CCC Q-Jet is that it tries to maintain the magical 14:7:1 air/fuel ratio. Countless carb tuners have tried to achieve that perfect ratio for as long as there's been carbs. This often mis-understood system does that all day long. It's a lack of upkeep, proper service and age/ mileage that causes these Q-Jet's bad reputation. Most are pretty tired if they havn't been rebuilt. Many were screwed with by the local shadetree mechanics or teenage newBs. When I was in high school, these cars were all over the used car lots. I laughed at the kids who had 80's Monte/Grand Prix 305's, Olds & Regal 307's, carb'd F-body's,' cause few of them seemed to run right. "Common Knowledge" was to cut & plug off the vacuum lines, pull the smog pump & AC, and run it! God, I remember seeing these cars going for dirt cheap due to "Carb problems". Wish I had some more insight then.

what kind of gas mileage are you getting?

She's been gettin about 19-22 mpg on the highway if: I leave the windows up, stay off the secondaries, and don't use the A/C. Thank God its getting cooler up here! Thats on Mobile 93 octane, 2:73 gears, sweetened Q-Jet rods (slightly richer), Edelbrock intake 3701, stock exhaust, Edelbrock water pump w/ Stant HD 180* thermostat which keeps her temp below 175 on the highway. My 2003 S10 Blazer 4x4 4dr has a fuel injected 4.3 (262ci) & I only manage to get about 15-17 on the highway...LOL!!! I bet that when I get a bigger exhaust and some L69/ ZZ4 conv. exhaust manifolds, I'll improve that number a bit. I haven't seen headers that impress me for these cars. I don't like to cook my brake fluid or kill my arms/shoulders doing a spark plug change. The stock set-up is hard enough to work around!