Heres the skinny. O.E.M. 1972 quadrajet 4MV 7042910 on my 72c10 with 350. I've been experiencing irregularities with my trucks performance as of late. Engine info: 350 with .040 over bore, compcams XE250H RV cam, 882 heads, roller tip rockers, double roller timing set. And about 20k miles kn the rebuild. Engine started acting funny a couple of months ago. Sounded different drove different. Almost like it was lean and had a vacuum leak with to much timing. I KNOW RIGHT!
So j finally got around to pulling the top of the carb of tonight. Other than the typical stuff u might expect from a 40 something year old carb. (Its been rebuilt 3 times, twice by the same shop, and once by me.) I was depressed to find the Venturi booster walls of the primaries with hairline cracks running vertically. Also the secondary pull over wells full of fuel and the side vacuum chambers full of fuel as well. Which by the way, might explain why one of my hei vacuum canisters was full of fuel a couple of years ago. ARRGGHHH!! It's all beginning to make sense! Dammit. Oh, sorry, you're still here? Cool. Thanks. I'm pretty sure that cracked venturi walls is not the most common issue that many Qjet owners face. But I can only imagine what kind of issues this causes. Let's try and name them off: lean mixture, loss of vacuum, flooding, idle instabilty, and weird noises. Honestly sometimes my truck sounds like a boiling kettle on the stove or like one of those bird whistles that you put water in and blew threw. Yeah, exactly like those whistles. I swear it is the weirdest sound and I was afraid to ask someone for fear of THE LOOK. The look of " Hey buddy, are you ok? You been reading on the internet to much." You know the look. Anyways. Maybe this all goes back to that one time when I first had my carb rebuilt and I dropped it upside down on the concrete? Who knows. Point is, it is what it is. And I'm not happy. But all is not lost. My really good friend had offered me his Brand New, seriously a week old, 1406 edelbrock with his brand new Performer EPS intake. Yeah, that's the type of friend he is. Well that and the fact he needs to rebuild his motor. Which we found out 2 days ago. So he gets a 383 stroker with aluminum heads and a scar rotating assembly, and hes gonna give me his 041 350HP heads, new intake and carb setup with 1" spcaer. The world works in mysterious ways. And you might ask what I have done for him? I rewired his 71 c10 swb, helped install all of his suspension and interior parts, and help him diagnose his own engine issues. All without asking for a single thing, just only to let me help him and maybe a beer or two. The reason why I did this for my friend. Because when I blew the head gasket on my truck about 4 years ago, I had NO ONE to help me. NO ONE. Sure i had a buddy with a hoist, and a buddy that could help drink my beer. But I did not have some one to show me how to reassemble my engine, how to set valve lash, how to torque engine fasteners, how to rebuild a carburetor, how to bench bleed a master cylinder, how to recurve mu distributor. I did it all myself. I loved it, but it was hard. And I wish I did have someone with some knowledge to learn from and bounce ideas off of. So, I wanted to be that guy to my friend. And I dont regret one bit. But I'm rambling now and I have to get this thing back together so I can go to work in the morning. As my friend always tells me, "Its called hotrodding, Mike."
