I have experience rebuilding Q-jets going back to the late 80s(Was scared to death of them til I finally tackled one using Doug Roe's excellent book that literally shows every single step necessary so anyone can do it, magazine articles will only cause someone fail first time out) anyway, I'd say I have rebuilt Q-Jets on 6-7 cars, and about 20 different times on said cars...never, ever, ever had an issue getting the pin out. Think once it was hard to push one back in (Had a nail file behind it, just stiff going back in) but this time...can't get it out! Tried the usual, not perfect tool, lightly tapping with an awl , nothing. Didn't even begin to work, nothing popping out towards the center of the carb. I think I used a punch once, many years ago, but couldn't find one in my tools. Again the pin would always easily slide out with 3-4 gentle taps. Anyway, I was just guessing that somehow it was wedged in there by the awl....so, I was going to ask here if there was a better option than drilling, but the board as everyone knows, was down for awhile... so, I got the smallest drill bit I could find (1 16th of an inch) and tried to drill it out...and...wore the bit out...couldn't go to the next size up, so a few days later, I got a "titanium" Nitride (yeah, right China, tell me all about it) bits....and wore out or broke off several. One just about flush with the hole! good grief...finally , warily went up a size with the bit (I am beginning to think Carb will be junk, but felt out of options) Used the bigger bit, and finally got thru the other side! Yay! but...the arm was still in place. Looked like the edge of the pin was still on the inner side...so, kept drilling backwards/forwards...lots of metal shavings....still...no dice....did not want to go up to the 3/32 size bit...took awhile to even get it started. Finally got it in and made the hole bigger, and yet, that arm will not pop up! I tried tapping it lightly, pried with a screwdriver...won't budge. Arm still moves freely, which is a good sign, I guess....I just can't imagine why it can easily move up and down, I can see through a now much bigger hole, but that arm won't come out... Any thoughts? Anyone have this issue before????
That's interesting. I have done a thousand or so and not had one that wouldn't push through. May have corroded or somebody put something in that didn't belong there. Is that a 76 Quadrajet? We use a good quality roll pin punch and sometimes does take a good hit to get it moving.
Yes! very good eye, it's a 1976. I am putting it on a 1977 350 2 barrel Regal (well, in theory I'll put it on my car) I was fortunate enough to get it and the Intake from a member here at a reasonable price (money is a bit tight what with other issues that needed to be taken care of) I wonder if you are right, some odd corrosion, or a non standard pin..nothing looks like it was messed with, it still moves as is should as I mentioned above. Really annoys me, as the friend that's going to help with the swap can't for the life of him understand why I would want to put a used Quadra-insert-the-insulting-name instead of a brand new shiny Carter AF, err Edelbrock. So I just can't wait to show him what a Q-Jet can do (I've had Lincoln's the last 10 years, til I got this Buick, even thought of trying to put a Q-Jet on one of them) and I can't even get the airhorn off of this carb Oh, if I can ask, the semi-Triangle looking think, above the accelerator Pump rod...looks like a cover of some sort is missing (I recall rectangular metal covers, or a cork like thing on a piece of shiny metal on my 60s Buicks) I see part of I can see down, like a vent tube, or something might be missing?
That triangle metal cover thingy isn't on the 76 so you aren't missing anything. That is a great Quadrajet to build. Has 800+ cfm ability, internal APT, and other nice features. If you need any parts or kits, check out our store. Glad to help any way we can. I have seen many different objects used in place of the roll pin, like nails, wire and other stuff.
Stop trying... it is not required to remove the accelerator pump arm to remove the top.. simply rotate the top once it comes up, and disengage the linkage. I only remove that roll pin when I am restoring a carb, on the dyno, we take them apart without fussing with that all the time.
NEVER use an awl to remove a roll pin it will expand the pin and lodge it in place. I've driven out tens of thousands of them w/o any issues, but we do have a roll pin punch machined to the perfect size for the job and we "spot face" the punch every 6-8 months or so to make sure it drives the pin out evenly. For those reading this IF you were to run into a situation where the pin woln't come out, just cut the link down to the baseplate and replace it with the older style that uses a clip on the end. That is a quick and simple fix for an issue like this.....Cliff
X2 The older style (clip on) pump rod allows you to remove rod easily and allowing for easier air horn removal or changing of the accelerator pump arm hole location
Now I know, that make sense, thx ....it just never was an issue before doing it this way, don't know why I was lucky for decades, clearly...my luck ran out. Finally got it out.... then waited a bit to tackle taking it completely apart.... I have 2 q-jet books, Doug Roe's and someone named Cliff Ruggles that I got about a year ago...seems to have good suggestions in it too! anyway, the Doug Roe book my Dad bought in the early 70s it looks like, ($4.95!!!) it's the book I am most used to.... but , I don't have his updated book...anyway, was quite shocked to see the Power piston look the way it does, and...I thought I had somehow broken it...still a bit confused by it...looked at pics in Cliff's book. But, before that, I took all these pics, cuz I wasn't sure what was going on...why did they go to a threaded part on it? Why did they change it so completely? Sure confused me... So, a few questions if I may... 1)that pin, is it supposed to be like that? stick out like that? Is this the way it should have come "apart"? I looked at Cliff's book after I took my gloves off, and saw it was threaded at the base of it. I just used WD-40 thinking it was stuck in there, but ended up turning it out with needle nose. 2)How will I put it back in? Seems it should have a slot on top to screw it back in. Just use Needle nose again? 3) should the top half of the PP come out with the gasket, or did they have the flap the wrong way? I always remember to get that flap underneath, at least with the older styled ones. I guess 10 years since I have touched a q-jet (and this one is by far the "newest" one) has turned me back into a newbie with these... Thx...
Congrats, your M4M carb has the adjustable part throttle feature (APT) covered in Cliff Ruggles book. It all looks fine, the pin is supposed to stick out like that. Yes, you should slot the top of the piston stop, I use a thin cutting disc on a dremel tool. you then can use a flat bladed screw driver to set the piston stop to the height that gives you optimal fuel at off idle RPMs (again, covered in Cliff's book). Knock the aluminum plug out of the airhorn, and tap 1/2 way through the casting to fit a 1/8" ? pipe plug. Sounds more complicated than it is, and works terrific for dialing in the carb.
The Power Piston does not come out with the gasket if the plastic retainer is doing it's job. Our kits come with a new one, as 9 times out of 10 the old ones are cracked, broken, or don't hold the PP down as they should.....
what, that moron still doesn't have that q-jet back together? no. Friend that will help with intake installation has been very busy with his future wife getting ready for their wedding, so I knew nothing was going to happen til the middle of June...anyways...gave me time to study Cliff Ruggles book, as this carb is much newer than any I had ever dealt with before(and I mentioned above, the Doug Roe book is old I have, only up to '74) so, a few questions if I may, cuz I am confused about a few things. 1) the gasket fit, this is supposed to be the correct one for this carb, does it look "ok"? Perhaps semi-universal with that screw/bolt hole in upper right hand corner? (Of course original was in many pieces) 2) From Cliff Ruggles book (hope its ok to take a pic here from it, just easier to explain with pic) I have a 76 carb with APT, and it has that weird looking "nipple" whatever you want to call it pencil is pointing to. I also have a black plastic container that I don't see in the book. looks like an old 24-36 picture film roll container(It isn't, just took a pic with it back in the carb, hard to see) here is pic without it in place. is this just a reservoir? Nothing? Had it already been "fixed" by this point in 76? Very confused here here it is in place
I know I had other questions that I should have written down...oh yeah, the APT screw that I didn't know about when I took it out...I of course didn't count turns while taking it out. Is there a base adjustment? Something akin to idle mixture screws turned in all the way then backed out 2 1/2, 3 turns? Obviously, more of an issue with this... thanks!
The gasket is semi universal. There are newer carbs that have that extra baseplate screw. I typically trim that extra piece off when not needed, but it doesn't hurt anything leaving it there. The plastic cup just fills the void left by the 1975 design anaeroid device that was discontinued. I suppose it acts as a baffle, so fuel has less of a chance to splash around in that well and potentially escape at the air horn. For the apt setting, I usually go 3 or 3.5 turns from bottom and tune from there.
Some folks leave out the plastic filler cup to increase bowl volume. Others will tell you that the engine will stall during hard braking if this is done. I haven't had on in my 1977 carb for 30 years and never had an issue, and I've hit the brakes pretty hard at the track running over 120mph to keep from breaking out! Those black gaskets completely SUCK. Fine if you don't plan on taking it back apart, which shouldn't happen as any tuning usually requires removing the airhorn, not the baseplate. They are supposed to be a "non-stick" variety but they are do just the opposite. The APT screws were pre-set by the factory as each one of those units was precisely calibrated exactly for the application. Unless you are using on the original engine with all of the emission devices in place and operational, no real reason to worry about it much. I would set it about middle of its travel and custom tune once the carb is in place. Depending on what you are using it on and what jets and metering rods are in it, you may or may not have enough "range" with the APT screw to dial it in. The factory used a lot of "K" metering rods in those units, so they only have a .005" taper on the entire upper section, so very limited adjustment with the APT screw right to start with.......Cliff
thanks guys! Every q-jet I have rebuilt was one I took off my car, so I knew it ran (perhaps not well, but ran!) so swapping intakes and carbs, with oh, I don't know...everyone I know thinking it either won't make any difference performance or mileage wise or what if it runs worse than it did with the 2 barrel??? I have total confidence in the carb (if it's a solid one) , less in me since so much had changed with this model . So trying to make sure everything is right... Ok, a few more questions if I may.. the choke flap/primary air valve, that choke rod , do you see all the "slop" the gap there? Is there I clip? seems like it wouldn't need one of course, but it sure moves around a lot. and the screw there. How tight should I make it? it feels like its binding a bit now, but if I make it looser, it seems like the screw might work it's way loose. Previous q-jets I had did not have a screw on those earlier q-jets... Oh, the accelerator pump rod, inner or outer hole? This is a bone stock 77 350(well better exhaust, thats it so far) Another question, secondary metering rods are CZ, LL (extra long power tips) Never seen any this thick before, will they be fine for this application? thx
You have the flat piece on backwards. The odd shaped hole is supposed ti fit into the shaft where the screw goes in. I will try to get a photo of what I am talking about...
Ah, you were right, thanks! Not many pics I could find , one was too small to tell which was was which. I thought the side withe part number would be the part facing out...now it doesn't bind!
when your putin together your puzzle look for circular screw or lockwasher marks. That helps all over the place on your carb. The float clip The part you put your finger on when checking the float, spread it out a little so the air horn puts slight pressure on it when you set it on. Loose float no good. As far as your accelerator pin, I have used anything and everything from a skinny nail, the tip of a fat nail, a pic, an awl, a drywal screw, a secondary needle I didnt care about, even the correct roll pin punch, or pin punch, never a problem. You must have that special ability to not listen to that voice in your head tellin you stop before you bastardize somthing. Thats ok, fearles is good. Just remember . IF ITS HARD, YOUR DOING IT WRONG.
