Having Chevelle Problems, Getting pissed off. Gear-Heads please help!

[Dwn4BassAlan]

So for the past 2 months I've had some weird issue with the motor I believe. I started it up from my friends house one night and we live on a hill so there's lots of hard braking involved. I come down the street, slow to make the turn and as I start to turn my car dies out? I'm like WTF? start it up, and keep going. As I go further down the hill I notice that every time I brake the engine almost dies out, every time, no matter what, the RPM's either drop completely before coming back, or if I brake hard enough, the car will sometimes die all the way. At first I thought a loose ground? Tried everything, all the power and grounds tightened and covered in some electrical paste, but no solution. I looked it up online and people say all the time it's the carb, that the floats need adjustment, or the power vacuum on the brakes. So I took it to my mechanic, he says he fixes it, I go get it, and as I'm braking to leave the driveway, guess what happens? It almost dies, so I back up, leave it with him again, and hope he fixes it this time. I call him and he says it's ready, "come pick it up it's purring" were his words so just picked it up YESTERDAY and he has had it for a combined 3 (all of february and march, april 20th-june10th) months out of 6 months this entire year, and I'm done. I felt bad because he got a staph infection and ended up in the hospital, so he has his one mechanic do everything for him, but I'm not down with that, nor can I wait 1 month for every damn repair. So I start driving home and IMMEDIATELY notice a few problems. The engine STILL dies/almost dies under any braking, and now whenever I'm at speed in gear, my car jerks back and forth alot? Like the ride is very rough, and it is constant as long as I'm on the gas, once I press the clutch or put it in neutral it stops? Is that a carburetor or transmission problem? It's not really lugging per say, but it's hard to describe. I thought maybe the vacuum seal between the carb and the engine is off? But I know my mechanic has never given me car to me in such noticeably bad condition, and as much as I trust him and how he has treated me and everything, I can't help but feel suspicious. So I already made an appointment with a local shop and I'm taking it in for an oil change tomorrow and I'll discuss this issue with them as well. But if anyone has any ideas, please let me know! I'm dying to get it fixed, and 3 repair visits later, I'm worse than I started.

[OrionStang]

It could somehow be vacuum related, especially the "chugging".

If you are at say 60mph and get on the brakes hard, does it almost die right away? Or not until the car is almost stopped? Or is it only at slow around town driving?

Im thinking something with the master cylinder (and the vacuum lines that go to it).

Not entirely familiar with that car, all GM really, but thats where i'd start.

[tdsa23]

do you have a carburetor or fuel injected?

[Dwn4BassAlan]

It could somehow be vacuum related, especially the "chugging".

If you are at say 60mph and get on the brakes hard, does it almost die right away? Or not until the car is almost stopped? Or is it only at slow around town driving?

Im thinking something with the master cylinder (and the vacuum lines that go to it).

Not entirely familiar with that car, all GM really, but thats where i'd start.

If I'm doing like 45+ and I come up make a turn and I slow down relatively quickly, it will die almost right away, but if I'm going around town and I come to a stop sign, it will get really slow, jugg for a second, then come back once the car has stopped moving. The moment I let go of the brake pedal, it comes back.

Almost EVERY single forum says the floats are the problem, everyone fixes it by replacing the carb, or adjusting the floats. And I just had it sent out for a carb rebuilding, then they tuned it this past weekend.....................like WTF. It's so ridiculous......... I'm not this mechanical so I can't really do this stuff myself, but I just want to better understand what it might be before I go talk to the mechanic. Because I'm not dumping money into the stupid ass carb. Which I've rebuilt twice now. And everyone says it's always Holleys, which mine is of course, and that switching to a qjet or edelbrock fixes it every time.

[Dwn4BassAlan]

do you have a carburetor or fuel injected?

It's a carb. Holley 9834 I believe.

[OrionStang]

Edlebrock>Holley LOL.

I wish you were closer so I could get hands on. If I think of anything ill post up.

[Dwn4BassAlan]

Also;

When I was at the drive-thru at InNOut, when i was just idling, it would be at a constant idle speed, I don't have an RPM meter but it was pretty high. Probably around 800-900 or so. And as I'm sitting there it would be idling, then every 20 seconds or so the engine RPM would just drop, usually for only a very short time, less than a second or so, and then come back up. It was almost like a pause. It would be like "vrm-vrm-vrm-vrm-vrm-vrm-vrm-dip-vrm-vrm-vrm-vrm-vrm" just randomly. At one point it almost didn't recover and the engine starting glugging and almost died. It was really weird. I've been through the drive thru hundreds of times and that never happened before. But I have noticed the idle dip before, it has done that a few times for a while now, but I never really noticed it because it's so short. It's almost like the timing was re-setting or something, but I just had the timing fixed, and it does not do that anymore from what I can tell. Now I just have the stalling problem.

[Dwn4BassAlan]

Edlebrock>Holley LOL.

I wish you were closer so I could get hands on. If I think of anything ill post up.

I told my mechanic I wanted to replace it too, but he was like, "you already have the manifold so lets just rebuild it" well that worked out great didn't it..........

[Airborne]

Wish you were near me man. I can fix ANYTHING Chevy but I need to be hands on.

I doubt the problem is the make of the carb. Tens of thousands of people with the same carb would be having the same issue. Have you looked at the fuel pump? How old is it? How about the gas tank?

I really think vacuum leak. There aren't too many things it could be.

Does the car have a vacuum advance?

[Dwn4BassAlan]

Wish you were near me man. I can fix ANYTHING Chevy but I need to be hands on.

I doubt the problem is the make of the carb. Tens of thousands of people with the same carb would be having the same issue. Have you looked at the fuel pump? How old is it? How about the gas tank?

I really think vacuum leak. There aren't too many things it could be.

Does the car have a vacuum advance?

The fuel pump and the gas tank are new, replaced them last year when I bought it. There's a million vacuum things I also see. People say the brake vacuum seal, seals to/from the carb, but the thing is, I don't know which is which lol. I'm not that knowledgeable when it comes to this.

But I believe the vacuum advance is the brakes right? I don't know if I have an adjustable vacuum advance though? Or how to check the vacuum signal?