Ugh! I finished swapping my carb tonight with my rebuilt Quadrajet and I tightened the rear passenger mounting bolt too much. I heard a little pop and immediately backed off. Looked closely and I can see a hairline crack near what I believe is the fast idle adjusting mechanism. See pictures below. Should I be concerned about this? Haven't driven around enough to know if there's an issues. My only thought is that with this slight crack the base may be bent ever so slightly. Perhaps the gasket just above is no longer seated tight tight tight, or maybe nearby vacuum airways will not be sealed properly, or heaven forbid fuel sprays out on the hot engine and am I burned alive in my car ... OK I guess I doubt that last one will happen but my mind wanders to all kinds of worst case scenarios. Your thoughts? Is this just paranoia? I am a noob at some things but I really did swap a carb once before and not torque the crap out the bolts, I don't know why I did it this time. If this IS a really really big deal then I guess I have no choice but to have my old one rebuilt. Argh. Really no interest in doing it myself. Somebody please tell me that this is not an engine block we're talking about and it can live with a hairline crack.

 

Well, I had let it sit overnight and came out today to fire it up ... the car started at first but idled like crap. A cloud of blue-like gas fumes enveloped the garage, then dissipated slowly when I shut the car off because it was running so badly. I don't think I trust this carb, the car ran OK with the old carb, the reason I'm swapping is due to strong fuel smell from the old one (probable leak from plugs in bottom of carb as other group members have told me). Plus, the stock carb was 23 years old afterall and I happened to have this rebuilt one I had done for a previous project car that I've abandoned since I found my current car. The *only* relevant change is my broken pump-to-carb fuel hard line that I've temporarily replaced with a piece of rubber fuel hose, a replacement is on order from Classic Tube. The hose is not kinked and I know I have fuel coming up to the carb since it did indeed start up and run (albeit like crap) so I'm thinking that this carb is just junk despite the rebuild, not to mention the damn crack I put in it, so I could be introducing a vacuum leak there. Nothing else has changed, all hoses emissions-wise are connected and I even replaced a few that were hard when I swapped the carb. After a few times running roughly like this I was a little unnerved by all the gas smell and cloud of crap coming out of the car and let it sit. Then I tried to start again and now it won't start at all, just keeps on cranking, though I know the battery is getting weak so that's part of the problem. I have to charge it back up. I'm thinking of just buying a new/rebuilt unit from guaranteedcarbs.com. The prices are reasonable and they seem to ship quickly. Other opinions are welcome in the meantime!

 

I guess by the lack of replies everybody realizes I am an idiot that I cracked the carb! No hard feelings ... Turns out part of the problem with my Haynes manual which said to tighten the short bolts to 130 ft lbs and the long bolts 85 ft lbs ... yikes! That seems completely wrong. I read elsewhere on the web that 15 or 20 ft lbs is all it takes. Maybe I was reading in-lbs (gasp). Crap that MUST be what I did. I misread in-lbs for ft-lbs. I guess I really did goof up! Lesson learned ... I've placed an order for another carb thru guaranteedcarbs.com ... should arrive later this week!

 

Oh, I thought you were just relating your experience. I didn't realize you wanted responses.

Oops. Only off by a factor of 12. . .

 

So did you ever find out what it was. Is it the carburetor. I get the same blue smoke but it was just a little and now it is a lot. I switched out the qjet for another qjet (the new one is used) But they still both smoke and idle like ****. Now i just get a lot of blue smoke and it doesn't want to stop.

 

WHOAH! 130ft lbs? You only torque head bolts down 75ft lbs, let alone 130ft lbs for carb studs. Sure it doesn't say inch lbs? That would make more sense to me, roughly 10ft lbs.

You wouldn't have to worry about gas spewing everywhere outside of the crack and burning you alive in your car. What you have created is a VACUUM leak, meaning it is sucking air in, not forcing air out. Most you would have to worry about is a crappy running car...oh yeah you have that =P

Get a vacuum gauge on there and see what vacuum you are pulling. Who knows, you may not have that much of a leak, it may just be the carb you put on. May have to tweak with the tuning.

If you ARE pulling a huge vacuum leak, you could JB weld the crack closed, and see how it seals and performs there after, as a last resort before buying a whole 'nother carburetor.

 

That kind of tightening of the long bolts mostly FUBAR'd the airhorn, and possibly the body. Very common among used q-jets.

 

Can't you just unbolt the cracked base of the carb and just bolt a new one on?
(I know S*** all about Q-jets so im probly wrong).

 

The long bolts go through the air horn on the top of the carb. If overtorqued, they'll do more damage than the short ones in the back on the base only.

I'm guessing the cracked base is secondary to what's really wrong.

 

Well I have a happy ending to report ... I had ordered a new QJet from Guaranteed Carbs, and was gone on vacation for a week. I just got back and swapped carbs, and CAREFULLY tightened down the new one ... Yes, the original mistake was that I was reading in-lbs for ft-lbs. I never tightened head bolts before and someone has also told me that 75 ft-lbs is what you use for head bolts so now I have some perspective and won't ever make this mistake again LOL.

The good news is that with the new carb on and the battery charged up, the car fired right up (with initial heavy cranking to get some gas to the new carb, of course) and it purrs like a kitten. I took a short test drive to test both the carb and my new brake job, and I least I did the brakes correctly as they work great (I had at least done brake work before). The only minor adjustment I can see being an issue is that the idle speed is just a touch low with the engine warm, so I need to tweak slightly.

There was only an initial few puffs of blue-gray smoke that has since gone away, and I would guess was due to the crappy old gas that was in the old carb that I cracked. That carb had sat atop my old 84 project car for a while and the gas was old and possibly varnished ... the carb might have been gunked on the inside, plus I cracked it probably causing a vacuum leak and leading to the rough running situation. Or as five7kid said, I could've also ruined the air horn when I tightened the living crap out of the long bolts in the front.

Thanks for all the replies and for bearing with me on this boneheaded mistake. Who knows, I might have had to replace the carb anyway even if I hadn't cracked it if there was bad gas in it.

 

Glad to hear the happy ending. Idle speed adjustments are practically a given when you install a carb. Did you check the MCS dwell & TPS voltage yet?

Got a pic of the new carb?

 

Um, this did not dawn on you as beeing too much for a CARB? Holy crap. I'm amazed you did not pull the threads out of the manifold first. Those bolts should be hand snug with a short little 3/8" drive wrench. If you torqued those bolts to 20-30 ft lbs you still would have rendered the carb trash because the air horn would permenantly warp and leak. Look how tiny and soft the carb body parts are!

 

Wow, that almost makes my stupidest move seem like a smart one.

But seriously though, when I put my heads on, progressively to 75ft lbs, I messed up my right shoulder pretty bad. How did you even manage to get the wrench to put down 130ft/lbs of torque? You must have had your feet against the block pulling with all your might...good thing that wrench didn't slip off, or else you might not have been with us to make this post in the first place.

 

Nope, it didn't dawn on me regarding the torque. I'm actually not a dumb guy, but this is my first stretch doing all my own work. Previously I learned some basics from friends and usually they did a lot of work and I watched and learned. This time, I learned all on my own how to put torque specs in perspective. It's too bad I ruined the carb but I'll never make this mistake again.

As for actually getting a wrench to 130 ft/lbs ... I'm sure I didn't. I didn't use a torque wrench. But I did get them bolts tight ... heh ... tight enough to crack the base.

Five7kid, I haven't done any adjustments yet with regard to idle, dwell, etc. I'm not sure what dwell even is. I have a Rochester Carb book here that I need to crack open and take a look. I'm betting there's a thread around here that can help me tune it as well, if you guys know where it is. If not I'll just search the forums.

Out of the box the carb is running "very good" with the slight need for idle adjust as I said. It idles around 700 RPMs I'd say ... kind of bounces a tiny bit, 600-700 and back, not rapidly, but slowly. Not quite enough to stall... actually nice exhaust tones at that RPM. Looking forward to learning how to tune it properly.

BTW my Goodyear fuel hose solution worked for the fuel line I previously mangled. I have some 3/8 on the carb sticking out a few inches, and another small piece at the pump, bridged with fuel hose and clamps that travels around the smog pump and up past the air diverter assembly. I found the correct replacement part at Classic Tube, part # CAC1018-OE which is actually listed for 1984 Camaro Z28, but when matched up against my old line it is indeed the same part. Will wait to replace as the water pump will have to come off to get that line back where it belongs. Now that the car is driveable I think I'll leave well enough alone for a bit!

I don't have a pict handy but I will snap one soon and post it here. I do highly recommend Guaranteed Carbs based on my experience with them so far.

 

Hey man, it's a live and learn process. Like you said, you will never make that mistake of over torquing again. I'll never make the mistake of not taping my distributor hole shut when the distributor is out, and a buddy of mine will never again make the mistake of putting his throwout bearing in backwards.

 

As promised, here's a picture of the new carb. Nice and clean and shiny. I got an analog Sears dwell meter on eBay since I last wrote. I cannot figure out where the magical green lead is that I'm looking to connect to for the positive terminal. I'll look around some more in the threads for tips/picts.

 

very interesting thread- thats all all say heheee

i only tighten them down just enough to be just snug real good i cant believe the bolts didnt break or pull right out of the manifold, wow..

thats a freaking sharp early bird! :O

wheres more pics and info at ?

wow drool....!

how did you manage to come across such a nice car ?


keeping it all stock and original even wow that is rare to see and i am super glad

ive probably never seen a nicer cleaner more original early bird


and will never in person i know, hell i have the only early bird left around here, havent seen another in probably two years, maybe longer now





kudos

 

Look around the AC housing. It comes out of the bundle that goes into the fender liner area.

 

Hi Randy, thanks for the compliments. The origins of my 'bird are an interesting tale ... Back in May 2004, I had purchased a beat up '84 in Vermont for $750 as my first big automotive adventure. Some time passed and I did a little work with some friends here or there ... but then I saw my current car online for sale at a private dealer in Rehoboth, MA in spring 2005. I stopped and looked at it on the way back from a visit to Cape Cod that Memorial Day Weekend. It just happened to be the same color and very similar car to my beat up project car, which is what had grabbed my attention in the first place. I took some photos, including the VIN number ... but the price was almost $11,000 and I didn't have the money or the means ... I went home and figured that was the end of it. Fast forward just over a year later, in late July 2006 I looked on eBay randomly and I saw the very same car for sale by a private owner! I knew it because I had that picture of the VIN ... Long story short, I got together with the seller; he had bought it as an impulse purchase and had no time to enjoy it ... he had done nothing but add a CD-changer to the cargo area, replaced the speakers, and got an oil change (CD changer tactfully done, it still has the original cassette deck, but the oil change was done at Jiffy Lube .. yuck ... I found the receipt in one of the door pockets) Anyway I snapped it up for about $3600 less than the dealer price I had seen just a year earlier ... I guess that paid off!

I really enjoy the 82-84 birds for their unique character ... the wheel styles, the tail lights, dash styling, the functional power bulge. Those are my favorite years. How can I get involved in the Early Bird Club?

You can see a few more picts off my website at www.madavlen.net/photos, click the Trans Am link and enjoy. I am an amateur photographer and take a lot of nice picts with my Canon EOS-30D, I have to get a nice album up on the web at some point with some higher resolution shots. The interior of the car is nearly mint, the exterior is very, very good with some slight paint fade noticeable close up on the rear sail panels in particular ... all in all not bad for 23 years old!

Also, for the observant you will see I have "5.0 Liter H.O." stickers on the power bulge. It seems someone affixed these stickers out of a decal kit, but according to the VIN I indeed have an LG4 and not an L69. I also believe that is why there is both a small bird on the tip of the hood (not very noticeable in picts) and the decal on the bulge - I don't think it was normal to have BOTH these decals, I think it is supposed to have only one or the other. Again, somebody added the bulge decals before I purchased the car. There's actually a little more history I can share, as I actually spoke with the first owner a while back ... but I'll save that for another day. Need sleep!

Five7kid ... I think I found the magic wire bundle for my meter, yet I don't know how to tap into it. I thought there was some kind of free, non-connected spade terminal for the dwell meter. I'll submit a pict and show you what I mean.

 

Very nice car indeed, I have to agree is is probably one of the cleanest thirdgens I've ever seen. By the way, I like your license plate. I just noticed it. Congratulations on your learning processes. Too many people aren't willing to just go outside and at least try to work on their car themselves. You have a great attitude, even when you damaged your carb you were just like "oh well, I know not to do that again." Keep up the good work, and good luck with your future projects.

 

You should have a green plastic connector with a spade-like terminal inside it down between the blower motor and the fender. Sometimes it gets kind of buried down there. If you can't find it you can always tap into the lead going directly to the MCS.