BBR's 83GT - 552 BBF version 3.0 (at least)

[DanStokes]

Just a thought on the bowl vent tubes: Those things CAN come loose and find their way thru the engine - just ask David Freiburger (that's how they killed the Bonneville big block in the Camaro). Anyhow, there is an off-road vent tube that's single loop between the 2 vents with vents in the loop - had one on my 6 cylinder Camaro LSR effort. They seem to work fine and there;s no way it'll go thru the intake.

Dan

[BBR]

I thought it was the module making the noise. Now I'm not so sure. It stops when I pull the cap off and the tip of the rotor is warm. I suppose it could be noise generated by the fuel pump. I will disconnect the fuel pump later and see if that has an effect.

EDIT: I pulled the fuel pump fuse and it still makes the noise.

[BBR]

Ok this thing is possessed. Key on, MS on, coil & coil igniter have power.
1. Fuel pump fuse out - still has the noise
2. Unplugged TFI - still has the noise.
3. Pulled coil wire off coil - still has the noise.

[Russell]

Unplug the Alternator? Can't remember does it have an electric water pump (or was the BBF)? Electric fan? Just grabbing at straws

[BBR]

It's really weird. There is an electric fan, but it was not on. Water pump is mechanical.

I got to thinking about misfires and remembered that the wrong dwell setting in Megasquirt can cause them. I looked at our tune and it was 5.5ms, which is really high. I went back and checked a tune from Raceweek last year. It was set at 3.5 and it worked perfect then. So maybe that is the cause of my pop/misfire.

[Beagle]

sounds like a crystal singing... is everything still plugged in tight?

[Captain]

My 2bits.......
Free Electrons ALWAYS take ANY Route to Ground.......
Make sure Everything is Grounded, and/or "Bonded" to the BATTERY GROUND.
Your Ghostly Noise could be "Freed Electrons" screaming "Oh Yeah, Home Free" thru another circuit, i.e. Ignition pickups, crank position sensor, etc.
I found out that a Judson Brothers Electronic Mag/Coil Stores so much voltage, with the ignition off, master switch off, it Back Fed into the Starter Solenoid, and Ghostly would Crank the Car Over.
I had to put a Relay in to STOP it !!
Just a thought.

[BBR]

Just got the EVER LOVIN' CRAP shocked out of me. Went out and turned the ignition and MS on and it was making the noise, grabbed the coil wire and pulled it off the coil... KAPOW! Sucker zapped me big time.

After I recovered, I realized the buzz is coming from the COIL. It is only amplified by the distributor when connected. So weird. I had read about TFI coils making noise but I was sure it was coming from the distributor.

Ok mystery solved. Haha.

[Beagle]

Ouch!! I once bought a Bronco that PO thought had a flat cam lobe. It was a break in the coil casing, tick tick tick while it's zapping to ground... saw it at night with the hood open, so glad I wasn't digging around when it was running. I've had an HEI grab me from a tiny uninsulated area of the pliers (scratch in the coating) and 35 years later, I can relate still. POW POW POW POW POW POW, threw those pliers straight in the trash. These days I'd probably re-coat them, but I was, uh, upset. Glad it didn't send you into afib. :|

[BBR]

I monkeyed with it some more yesterday. I took the MSD coil off and installed the brand new Mallory TFI coil I got with all the EFi stuff for Greenbean. Heck if it didn't buzz louder than the MSD! Haha, so I just put the MSD back in. It only buzzes when the engine is not running. When it is running, it makes no noise at all.

The distributor cap is something I changed sometime after Raceweek. It was the cap that came on the Duraspark distributor we used for a while. It is black and has brass terminals so I though it would be better. Jonathan had a stock gray Motorcraft cap so I compared the two. I don't know if it makes a difference, rotor phasing maybe, but the towers on the black one are shifted about 1/8" counter clockwise on the distributor when compared to the Motorcraft one. I can't imagine that the difference is helping matters any, so I popped the Motorcraft one on for now.

If we get a break in the rain today, I will try to test drive it and see if we have made any improvement.

[DanStokes]

(fingers crossed for you)

Dan

[Beagle]

current draw?

[BBR]

Ok, switched to a different channel on the coil igniter and it only buzzes if the MS and coil are on but the igniter is not. Once I turn the key, the igniter gets power and the buzzing stops. If the igniter and the coil were on the same circuit, it would never buzz.

I managed to make a vid of the stutter I am chasing. It starts at about 1-3 psi. After I made this, I moved the coil wire so that it is now well away from the TFI and wiring. I have not driven it since because I had to leave.

I started thinking of it as a stutter and that opened up a whole new set of google results. Some caused by too much fuel and some caused by electrical noise, like a coil wire being too close to sensitive wiring.

[BBR]

And another one just for fun.

[BBR]

One thing I never did when changing the main body of this carburetor is to set the air bleeds back to match the original 650 main body. Literally I just used whatever air bleeds I had available in the shop to get it close. This sorta worked, but I decided to buy some brass set screws and put the exact sizes in. It was really pointless on my part to try and tune a carb with air bleeds in it that were "just what I had".

I used my bits to check the holes in the old 4777-7 650 main body. The bleeds in it are not adjustable.

Primary Idle AB = 79
Primary Main AB = 33
Secondary Idle AB = 63
Secondary Main AB = 33

I took the brass set screws and chucked them into the drill and used my little vice grips and pin vise (for the tiny ones) to hold the bits. Worked great.

I hope I can find some time this weekend to put them in and test drive it.