OK I'm going to say it (sorry :nonod: lars) Quadra bog, junk I've rebuilt my engine I've rebuilt my distributor and threw away 400 bucks on a new (i cant believe i did it ) edelbrock 1901 carb. The car runs like a 69 pick up truck (maybe worse) . Its running extremely lean I cup my hand over the carb and it sounds and runs great take it off and its putt putts along. Those adjustment screws are useless. I've read all lars papers etc... timing is advanced correctly. I am totaly lost why in the world should it be this difficult to adjust a freeken carb?? This should not be an art form!!! I'm past being sad it doesnt work I'm P.SSED OFF. Its either going to work today or I will personally get my $400 worth of pleasure smashing it into oblivion. :mad :mad :mad

Thanks for letting me vent I feel better already! :smash: :smash:

 

Ouch..I wish I could offer assistance.....Don't smash it though..i am sure someone will buy it from you!! Lars seems to also like the Demon Carbs...Maybe check out one of those :eek:

 

Have you tried sending it to Lars for set up? I know when Rhys had his Quadrabog problem, he eventually sent it to Lars and he's pretty happy with it now. For a couple of bucks and a little pride, you can save yourself from smashing $400. :smash:

 

Mick -
The stock Q-Jet replacement you bought will be jetted for a near-stock engine. If you have a good exhaust system and an efficient engine, the carb can easily run lean on you. Also, if you have the exhaust crossover groove just forward of your primary holes in your intake manifold you must use a special "pack" of carb base gaskets, or the carb mixtures/setup will be all screwed up. So check out the carb base gasket to assure nothing funny going on there. If all this ckecks out, you can raise the float level to 3/8" and bump your main jet size up 2 sizes. This will have quite an effect on how rich the carb will run even at idle.

 

Ouch... well, if it make you feel any better, which I'm sure it won't, :sad:, you just saved me 400 bucks, cuz it now looks like I won't be buying that new Edelbrock q-jet anytime soon. I was literally just now browsing their web-site and trying to find other info on them. I best have a go at rebuilding my original q-junk first, for the second time this year.

 

Mick -
Here - take a look at this thread and the photo I posted of the intake manifold. Does your intake look like this with the crossover channel in it? If it does, you need to use the special set of gaskets to prevent exhaust from dumping into the intake - some '69s use this setup:
http://forums.corvetteforum.com/zerothread?id=170938

Reading my old thread it's as if you did cut-and-paste on the words...! How funny :lol:


[Modified by lars, 1:29 PM 11/16/2001]

 

My 1901 ran fine right out of the box. Didnt up the power of the car, but ran smooth, and car started better. (now I discover it runs out of fuel in 2nd gear at WOT, which is a different but maybe related story) Of course the old Qjet I took off had no choke and probably was leaking down thru those infamous nonplugged holes, which made starting the car after sitting for a few days a 3-try effort.

In addition to checking the gasket covering the groove on your intake manifold, it sounds like you might have a leak around the base of the carb. This would let air in and make it run like crap. The first time I started my car with the new carb I had not yet plugged the power brake port on the back of the carb. Talk about runniing rough!! However, I could here the screaming sucking sound above the sound of the engine.

Lars, I found your instructions for adjusting the float level. Dumb question: can I do this with the carb on the car, or should I take it off? Thanks, MJ

 

well heres the other side of the fence........


i bought a remanufactured 1903 (9973) edelbrock qjet becuase i didnt want to wait on the turnaround time from lars (~4 days.....im impatient!!!)

the car started up the 1st time after playing with timing and ran soooooooooooooooo great!!!

i had to buy a special carb adjusting tool for those stupid caps they put on the front with the little sticks sticking out.....to adjust the mixture....

i installed an electric choke kit on the carb...

i adjusted the choke, the fast idle, and the mixture, and idle speed.


THE CAR NOW RUNS ABSOLUTELY PERFECT!!!

i spent like ~330 on the carb + a choke kit from jegs.

man i am so happy with the edelbrock qjet....

i hope you get yours straightened out!!


btw: i have 2101 intake and dynomax headers goin into true duals 2.5 inch.....

:cheers:

 

OK heres the results.

I do have the type of intake lars pictured in the refrenced thread. I do have 2/3 of the gasket pack installed. I'm missing the base gasket w/ the cutout but do have the metal plate installed and the above gasket. I had to take the car to shop down the street to have it set up because if I would have done it i would have got mad and just thrown it out.

Dwell was at 17 degrees I set the dwell just 2 days ago w/ an anolog dwell meter he set w/digital to 30 degrees hmmm???

Reset timing to 8 degrees BTDC.

Set adjustment screws.

Wow what a difference! The car has twice the power!! Still not perfect but a 100% improvemnt :) I have a feeling I'm still pulling air under the base gasket and when i install that it will improve it the last 10% :)

The main problem was the DWELL w/ the analog dwell meter if your having problems you may want to recheck w/a digital meter.

I'm sure the other part of the problem is I dont have the proper base gasket on.

Thanks for the replies I'm much happpier!!!

 

MNJack -
Yes, you can do the float with the carb on the car, but you have to lean over the side of the front fender the whole time. If this does not bother you, and you're good at getting the choke intermediate rod re-engaged, leave it on the car. Otherwise, you can just yank it off and do the whole operation on the workbench for a little more ease and comfort (my back can't take leaning over a Vette fender for very long anymore, so I tend to just yank the carbs off).

Mick -
Glad to see you're getting it sorted out. Make sure you eventually get that hi-temp lower gasket with the groove in it installed under the metal shield: the metal shield by itself will allow some exhaust gas to pass into the primary throttle bores. The gasket will eliminate this tendancy. I think I posted the part number for the gasket in the thread..... if I didn't, let me know and I'll get you the part number.
Good job!
By the way - don't feel bad: I bought a brand new multi-meter/dwell meter from Sears for my son for his birthday. He set up his dwell with it, and the car ran like garbage. I even checked his settings, because the car was running so horrible after he finished "tuning" it. I then hooked his car up to my big calibrated Sun engine analyzer and found that the dwell was set at about 17 degrees - the stinkin' analog Sears Craftsman dwell meter was defective! I flipped it upside down, and the @#$! thing was made in China. I took it back, got a refund, and bought a good American-designed (although not assembled in the US) digital meter for twice the price. But it works. Likewise, I have bought inexpensive (about $60) digital multimeters at Checkers, and these have also been grossly defective in their volt readings and dwell readings (off by more than 10%).

 

Also, just to play devil's advocate - I got a new 1901 carb, put in on my (mostly) stock 73, and right out of the box the car ran PERFECT. Some minor adjustments and the car now runs more relaible than ever before. No more hard morning stars, no more bogging, no more hiccups. It was absolutely perfect.

One thing -- the 1st one I got was a return and was missing some parts. I had to go back to the store to get a BRAND new one, but when I got a new one, it worked great.

 

I love Quadrajets. They are the best mass manufactured carb ever. Whenever someone says quadrabog or quadrajunk I instantly know they know little or nothing about them.

 

Cam Potter

I sense a little dig there. If I knew everything about carbs then I don't think I would feel the overwhelming need to post a help wanted message. Love em Hate em matter of taste I guess. But I don't feel the need to know how something is designed and built to be able to use it. i.e. microwave oven Don't exactly know what makes it tick but sure know how to use it. Same for carbs I at least know its a metered vaccuum leak and shouldnt be so difficult to calibrate that I need an advanced degree in carbotronics! Fortunately for all forum members we have the most knowledgeable person, carb and other mechanical matters relating to classic muscle cars, in my known universe on this forum the fabulous lars :yesnod: :yesnod: :cheers: thanks for all who gave input even you cam (by the way I'm sure of 1209 posts none where questions all where answers right?)

 

I am replacing my original Q-Jet with a Speed Demon 650 this weekend.

I will let you know how it goes and thedifferences.

 

Mick -
You're much too kind! I'm just glad you found the problem and got the thing up and running before they had you committed with a straight jacket...!

Your problems with the carb and the rest of the car are not uncommon - I see this pretty regularly. It doesn't take much of a subtle issue to create some big frustrations, and if you don't work on the Q-Jets all the time, a lot of the problems can be difficult, if not impossible, to spot. Right now, I have 4 Forum member Q-Jets ready for shipment out in the garage. Each one of them was causing some sort of problem, and most of them had been "professionally" worked on before coming out to me. Each one just needed some minor TLC, and a couple of them were problems related to installation issues or timing/ignition issues - not carb issues. So don't feel alone with your tuning problems: it's all part of the game and the hobby - you sort it all out one thing at a time.

Do I really have that many posts....? Gawd - I need to spend more time down in the garage with beers and carbs and less time up here on the computer...! :cheers:

 

Oh..... you were referring to Cam's 1200+ posts..... I just noticed I have almost 2,000.... I have no life! That's it! I'm off the Forum tonight. I'm gonna' go have a Cuban cigar, a Martini, and sit in the hot tub. Maybe the smell of gasoline and carb cleaner will wash out with the chlorine....

 

Lars,
right now my problem is solved but please e-mail me shipping instructions for my original 207 and how to pay you and i will ship it next week for your golden touch. Dont wanna go through this again so if i have a spare (the edelbrock when I get my original back) i wont have to rant and rave on the internet i can just bug my wife about the dishes instead! :jester

 

Hey, LARS.

I want one a dem quadra or holley thingies you gots hangin' round in your garage for my ole 66 junker. Whacha tink???

I gots dis berry grants demon thang on it now, n it don't run worph squat. :nonod: Mayhaps you B tradin' me, huh?? Da fuel line seems tiwaneese.

An whats dis cuban martini things you gots goin'?? What kinda timin' curves dat?
********************

********************
Jeff

 

Mick,

If you want to become a Quadra-geek, go to http://www.corvettefaq.com and get Lars' technical paper on tuning Q-jets. There is so much good info in there it is scary. :cheers:

 

Hey blkblt -
Is that there one of them Taiwanese Korvettes you got? Not only ya' got a Taiwanese gas line, but yor hood opens backards!

Mick -
I'll e-mail you some info on the Q-Jet rebuilds tomorrow. I'm still workin' on this cigar and the martini....


[Modified by lars, 12:36 AM 11/17/2001]