Vette(s): 1979 Black, Oyster interior purchased in March 1980
I 'm having trouble understanding your question. I have a 79 with a quadrajet and I'm guessing that is what you are talking about. The secondaries are controlled by vacuum. At idle and then raising rpm's to check if secondaries are opening may not be an accurate way to tell if secondaries are opening. I have a q-jet that was built by Sean Murphy, and when you are driving and give it full throttle, when the big secondaries open up you know it. You can feel and hear it. Even on a stock L-48 like I had, you know. If your secondaries aren't opening up, I suggest a carb rebuild and make sure you have no vacuum leaks. I've rebuilt stock q-jets and they are easy to rebuild. I wanted a tricked out q-jet so that is why I bought a SMI q-jet. Once again, check vacuum as there can be plenty of places for a leak on a corvette and then rebuild carb if needed.
Sorry if I led you to believe there is a vacuum secondary linkage like holley carbs. The quadrajet vacuum for the secondaries comes from the venturies on the primaries. The choke does have to be wide open and the engine will have to be at higher rpm for the secondaries. The quadrajet is a bit more technical than a holley , but on a street engine, a good quadrajet is great. It takes a bit more time and effort to adjust, but when you have it adjusted properly, it flat out works. The small primaries give it super throttle response and like I said earlier, when the secondaries open up when your engine is at the higher rpm range, it almost feels like you gave it a shot of nitrous. I've been playing with caes since the mid 70's street racing and drag racing at the local strips and the first thing I would always do was ditch the quadrajunk and get a holley. I even did that when I bought my Corvette in 1980. Afew years later I decided to go back to the quadrajet because I wanted the original back on. Once you learn about how they operate and fix the few things that were problems[fuel drippage from the plugs on the bottom], you will find out they are a good carb
yes 1979 cor 350 ci yes quad they do not open,idle is perfit,starts and runs normal,pulled off vaccum hose,it very I did not have vaccum test at this time,i think what I am asking is there something wrong with quad car runs pefect with only 2-barrel
I did not pull off hole air cleaner off just top of air cleaner,seems that they stuck,but no they are,i just needed
I what I sould be looking,vaccum leak? or something that's goes bad with quad 4,s thanks for your reply.dwa
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Quadrajets use a mechanical secondary. They will NOT open if the choke is closed, even a little. There is a small lock-out tab that will keep the secondary shaft from twisting the blades open if the choke is on. Once the choke is fully open, the tab drops, and then the secondary linkage will open the plates. Check your choke first. Then maybe spray a little WD40(or similar lubricant) onto the choke linkage/lock-out on the passenger side of the carb....the tab may just be stuck. Make sure the vacuum pull-off valve is pulling the linkage when the car starts, too.
|UPDATED|7/8/2016 7:39:57 PM (AZT)|/UPDATED|
____________________________________ Joel Adams C3VR Lifetime Member #56 My Link
thanks for your input that's want I been looking for,if I was still turning wrechs it would no problem getting problems just old age. I will say
there seems do no vaccum leaks car runs fine with a 2 barrel carb,next step is remove hole air cleaner and check carb, I thought the rear plates were stuck wd- 49 .will do, I well tell problem can be fixed by cleaning.good luck you say.dwa
yes found sec lever would not open lock out on carb holding it closed,all works fine,i pushed lever fro choke open all works fine,dont now what adjustment there is or maybe just stuck,it works fine now let it cool down and try again . there must be something that holds back seems everything is to loose but your pic pointed right to it good job thanks dwa
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