jchaussee

So short of the rebuild kit, what else should I get. I have the cleaner. I know I need new fuel filter. What is usually not in kit that I need to get. Also I need some jb weld to go over the plugs. Also it comes with a little plastic ruler for some adjustments, but it also shows some little compas looking thing for adjustments also in the rebuild instructions ( which really are not that helpfull. Any other tips, tricks, advice, etc would be appreciated. This is my first ever carb and carb rebuild.
Thank you

tylercamaro

iTrader: (1)

im gonna follow this thread because im goin to need to do the same thing soon, what rebuild kit did you get do you have any part numbers?

jchaussee

I just got the CarQuest brand that they had at my local parts store. It was 40 bucks. Could of got a cheaper one at Oriellys but I don't like to shop there

tylercamaro

iTrader: (1)

allright thanks, theres a few auto stores by me ill just give em a call and swing by there and as for your rebuild take plenty of pics

RocketyMan

nice nice...well first of all...what type of qjet is it? Is it a CC qjet?

Also, what are the numbers on the side of the carb. Usually they start out with like a 17020...something-something.

One thing that didn't come with my rebuild kit were those little gaskets for the airbleed valve.

But I managed to do OK without them I suppose, granted it was in alright condition.

One VERY prevalent problem is the fuel inlet nut. Those strip out VERY easily when trying to change the little fuel filter. I ended up having to JB weld mine in as well as jb welding the little primary plugs and secondary plugs.

Well that's just about everything I can think of off the top of my head. Lemme know how it goes.

jchaussee

it is non cc. It is a 17085226 carb. I am pretty ignorant when it comes to carbs , so should be interesting. Have done a lot of research about what steps to take because the instructions suck. Hoping to do this weekend. Will see how cold it is. BTW where in WA you at

oscarfromla

iTrader: (9)

I did research on Q-jet rebuild books when I was going to do mine, stumbled upon one called Rochester Carburetors, by Doug Roe. It's supposed to be a good one, I never ended up rebuilding one so I don't know first hand.

Stock Car Racer

There was two types of Quadrajets, one was electronic and the other was pure manual.

I would throw them all away and look for a used one off a 1970 or earlier Buick 455 or Oldsmobile or Pontiac.

The stupid myth about having to JB weld everything is a myth ...
Those carburetors worked just fine for about 30 years on all GM motors and the dealers never had a single problem with them.

Sometime around 1977 - they covered up the idle mixture screws with a plug that could be removed by carefully drilling a hole into the plug and pulling it out and making a tool to adjust the screw. I done dozens of them.

Since then they have came out with kits that you can use to convert them to a jet style where you can drill and tap the original jets and put in a Holley style jet and an aftermarket metering rod.

There are two styles of Rochester Spread Bore 4 BBL carbs.
A small one and a larger one.
The Big Blocks had the larger one - which was over 750 CFM

With a little bit of tweeking you can get them to perform as good as or better then a Holley.

The one big trick was to get rid of the vacuum secondaries and convert it to pure manual.. We would adjust the internal spring to the point of where it was so light that when the secondary butterflies opened up, the flaps on the top would dump open and the carb would practically make the car jump.

You had to be careful not to do it too far or else the flaps wouldn't close when you left off the throttle.

With the right metering rods you could really make the Q Jet perform.
Those carbs never needed all that back yard magic and witch craft that people are doing to them today.

You can buy a brand new Rochester Q Jet out of the Summit or Speedway Motors catalogs that is about 75 CFM larger then the largest Q Jet ever made that is already built to the hilt as cheap as or cheaper then trying to build a stock Q Jet...

RocketyMan

This is a good video which just kinda helps familiarize yourself with a qjet. Yeah..i know it's cold outside

http://www.spike.com/full-episode/qu...-rebuild/33035

As for the cold weather, I would recommend just taking your qjet and doing it in a nice cleared space inside.

Really what you're doing with the rebuild is cleaning the carb. Ensuring all the little holes are clean of debris..making sure the accel pump works...the float is to the correct level...needle and seat is resilient...idle mixture screws are clean (sometimes just taking the mixture screws out helps clean them)...

I'm in SW WA.




Throw them all away? ummm..no. Bad advice.

The leaky bottom plugs is not a myth. These carbs are made out of pot metal while the plugs were stamped steel. Pot Metal is very weak (and doesn't need to be strong because it is simply a carburetor) and has different expansion properties than steel does. With years and years of use, from heating up and cooling way down again and again, it is VERY possible for the plugs to lose their integrity and leak fuel. With just a little bit of JB weld or epoxy of some sort, that is good assurance to ensure they don't leak. How do you think qjets get all their nicknames? That's how you get the term "inherent design flaws."

They're awesome carbs. I fixed mine up a little and it runs perfect. Did the same thing to my buddies carb off his 70's K-5 and it runs perfect too.

I hate carburetors...but I love quadrajets.

White'89

iTrader: (8)

^^its funny how often I hear that phrase uttered.


The only thing I don't see here is that you should usually buy a new float as most of the time they are sold separately from the kit.

jchaussee

Well I got everything clean. Need to put it all back together. I think I should be all right exceot that I don't know how to adjust my idle mix screws, or my accelerator pump. I also have a bunch of rods for choke and pump and such that fell out that I need to puzzle back together. So any help on that or any other adjustments I need to make would be appreciated.

DoubleV

What kind of back yard magic are you refering to? I'm confused because it seemed you yourself described some back yard magic of your own.

DoubleV

Easiest thing to do is look at an exploded diagram of a carb. A picture is worth a 1000 words.

jchaussee

We'll as I am getting ready to put it back together I notice I am missing one vacume break. Is that normal. The diagrem shows two. I have one.

jchaussee

Also. What is the vacume breaks purpose. I noticed that the one I do have is probaly no good. Its plunger is really loose and does not stay in if I put my finger on the holes.

jchaussee

Ok. I got it back on car, but can't get it to start. Does it need primed or something? Is there a trick to getting it started the first time

Apeiron

Many applications only have one vacuum break. It limits the opening rate of the secondary air valve.

Have you got all the adjustments in the same positions they were in before you did the rebuild?

jchaussee

As far as I. Know. What all would need to be adjusted? I don't think I changed anything. There were these two screw type things in the front that a site siad to seat and then let back 1 and a half turns. But I think that is all I adjusted.

Apeiron

What site was it, and are you positive they were talking about quadrajets? 1 1/2 turns on the idle mixture screws isn't nearly enough on the long-tapered screws on an emissions-era Qjet. Try 4 or 5 turns to get it started, and then set the idle mixture from there.

RocketyMan

When I go junk yard hopping for qjet parts, I usually notice how the pontiac qjets have two of the vacuum breaks. And basically all the vacuum breaks do is hold the secondary throttle blades when your vacuum is high (i.e. when the engine isn't WOT or under any particular load).

But yeah..those little diaphragms usually break and get worn out. I would suggest just finding a good one you know that doesn't leak at the junk yard. I got mine for like $5 bucks if I can remember.


On all of mine, I had very good luck doing 3 and 1/2 turns out from lightly seated. 3 and 1/2 turns or 7pi revolutions or 1260 degrees.

jchaussee

It was a 4x4 web site I read. I will try to adjust again tommorow. Would that stop it from starting? I also adjusted the float to the specs that were in the instructions. But those were the two only things a adjusted. Was there other adjustments I should have made. I poured so fuel down carb. Would shoot out a small ball of flame , but would not start

jchaussee

And they were rebuilding an older carb on the site. But it was a qudrajet

naf

iTrader: (7)

Did you do anything else to this motor besides remove the carb and re-install it?

jchaussee

No. But perhaps I screwed something up in rebuild. I have never done one before.

naf

iTrader: (7)

It should at least try to run with some fuel poured in. ***** of flame are usually the result of a timing issue.

DoubleV

You need to adjust the carb to the proper specs of that particular carb for your particular application. If you talk to 10 different carb guys, they're all going to tell you something different. You need the actual settings/tuning info for YOUR carb. To adjust everything correctly, you need special tools ( or homemade ones ).

Are you certain you got every bit of crud out of your carb? This is the most common reason for failed carb rebuilds. Gotta clean out all those little passages real good.

As for the vacuum breaks; it may be different on your carb, but on an Olds CCC carb, the front vacuum break is for the choke AND to slow down the secondary air valve. The rear vacuum break is to open the choke up a little further about a minute after a cold start so it's not running so rich for too long ( emissins crap ). The rear vacuum break is contolled by timed vacuum controlled by the ECM and on older non computer cars, I don't recall ( adjustable vacuum break or thermal vacuum switch I suppose ). So if yours works like this, you don't need a RVB.

jchaussee

i am almost certain I cleaned it well. I would think that even if my adjustments were off, it would still starr, just run crappy. I am lost. Next step. Kerosene and a match

jchaussee

Also when it says lightly seated for the mixture screws, does that mean screwed all the way in. They are really long.

jchaussee

Also when it says lightly seated for the mixture screws, does that mean screwed all the way in. They are really long.

naf

iTrader: (7)

YES

RocketyMan

So turn them all the way in until they stop. But don't force anything!

Then turn them out a FULL 360 degrees 3 and 1/2 times.

Your float should be like 11/32 from the top if I remember correctly.

I can't remember if your Z/28 is a 305 or a 350?

tylercamaro

iTrader: (1)

it says by his name that its a 327. im pretty sure that may beimplied for his car but its just an assumpyion

jchaussee

Yeah it is a 327

RocketyMan

I'm pretty sure only 305s or 350s were put into our cars. So I wasn't exactly sure if that was right.

jchaussee

It was originaly a 305 tpi.PO put in the 327. I don't know what I did but I can't get it start now. I put gas down carb. Got it to make a small ball of flame but not start. Then I tried starting fluid and nothing at all. Not even a ball of flame. Frustrations are running high. Just want to get damn thing running so I can continue work on it. I am not mechanically inclined to diagnose problems. I can only fix if I know what they are. It worked before, then carb would flood out. Figuered I had a stuck float, hence the rebuild. But whatever I did, now nothing.

RocketyMan

Yes, it can be very frustrating not knowing the full situation at hand.

I would then tackle the ignition to make sure you get spark. If you're not getting that ball of flame anymore (which sounds pretty dangerous lol), I wonder if you are then getting spark.

In this situation, I would disconnect the fuel lines being pumped to your carb so that you can turn the engine over without having to worry about flooding the engine for that matter. Next I would take out one spark plug and try to position it so you can see it spark through your front window as your trying to start it (or have someone turn the key for you I guess, whichever case make sure you have a good grounding spot to see the spark).

Make sure you get spark and a very GOOD looking arc along with it. I.E. it would be most ideal to get a purple-ish spark as it's pretty much the hottest. Yellow spark would obviously be pretty weak. [Inherently the gap on your plugs should be correct. Something like .045" ???]

Then once you get spark, check your firing order. Everyone who owns a SBC should know this by heart!... 1,8,4,3,6,5,7,2 ( I struggle sometimes remember this too. ...first start with the FIRST piston #1 and then 8. Then half of 8 is 4...and subtract one is 3...times two is 6...subtract one is 5...then add two is 7...and then 2...something like that.)

Then once you know your firing order is correct. Make sure when the rotar is firing piston #1 that piston 1 is TDC. Easiest way to tell is look at the crank pulley (where you would see when to use a timing light). This could have happened if you took out your distributor and accidentally didn't put the gear in the right place.

I would start somewhere from there. That's just what I would do. I remember on my buddies k-5 I had to wiggle the coil to get spark for some reason.

naf

iTrader: (7)

Try getting it to start with the throttle held all the way down and without adding any fuel. See what it does.

How old are all of your ignition components? Test a plug like above. A spark tester can usually be 'borrowed' from one of the parts store chains.

jchaussee

Stupid question, but with only having fuel injected carbs, my coil wire went from distributor to intake area. Now it doesn't , so where is it.

naf

iTrader: (7)

'85 would have the large cap HEI distributor with the coil in the top of the cap. Later, small-cap, HEI distributors had a divorced coil mounted on the intake.

jchaussee

Ok. So with looking through books and stuff, I see my carb has a mixture control soliniod plug. Do I need that. I am trying to figre out if my carb is completely wrong for my application

jchaussee

Nevermind. Mine is grey. What is a grey one for??

naf

iTrader: (7)

Yours should look just like the one here if it's the original ccc-qjet:

https://www.thirdgen.org/forums/carb...-ccc-qjet.html

Don't know what gray is?

Some mechanical models had a plug where the MCS is for a cold enrichment solenoid but were not ccc-qjets. They can be distinguished from the computer controlled ones by the lack of the TPS.

jchaussee

Mine is not original. I must have the cold enrichment solenoid. Does that need to be hooked up??

jchaussee

I have now determined I am prob not getting fuel. I disconnected feul line. No gas coming out, though my filter gets wet, so I guess I am getting a tiny bit. I thought maybe the pump may have had to prime or something to get pumping, but guess not. I heard there is a rod that I should block before I remove my pump or something. Its mechanical . Is there a good thread on this. I also backed out my screws 4 times. No start. Got it to fire for half a second with starting fluid. I am just curious if I did not set float right, would that keep it from starting. Also when I crank it over without the throttle down, I hear a hissing type sound. Is that normal. Does not make it when I have pedel down

naf

iTrader: (7)

Is gas coming out of the fuel line when the engine is cranked? You can test it by hooking up a hose to the metal fuel line and dropping it into a bucket or other container. Then crank for a bit.

jchaussee

Ii took off line where it enters the filter housing. Nothing draining out. I may be low on fuel, my gauge really doenst work well. I will try that first. At least pumps for a 327 are cheap

naf

iTrader: (7)

Nothing will drain out unless the motor is cranking.

Pumps for a 327 are as cheap as pumps for a 305 or 350. Be sure to get the stock style WITH return. The return is important to prevent vapor lock.

jchaussee

Motor was cranking. Now as far as this return line goes, where does it go. The PO who did engine swap hacked it. I have chunks of hard line, mixed with rubber lines and on fuel pump I have one line from tank in and one line to carb. Another line on pump is capped off. I am assuming this is return line. Where does this line go. And what is vapor lock .

jchaussee

Its alive!!!!!! Never guess the problem.

tylercamaro

iTrader: (1)

so what did you do to get it back and running