Engine Stalling when Braking

[Rob_M]

Hey Guys,
I have a 68 427 Biscayne w/original power 4 piston disk brakes that has an issue when braking. After the car is fully warmed up, when I brake the engine stalls. As an example I will put it in neutral going 30 mph hit the brakes, and it stalls. If I take my foot off the brakes quick enough the engine will resume. It's as if I turn the key off and on quickly. It will even do this when in gear. Of course it dumps raw gas in the exhaust and I get a *very* loud pop out the back when I let up on the brakes.
I have checked for vaccuum leaks, blocked the vaccuum booster, adjusted the floats, (has a Holly), checked for loose wiring near my brake pedal and engine bay, etc - Nothing.
I am at a total loss on what is happening. I plan to replace the check valve that is on the front of the brake booster but like I mentioned earlier it still does it when the booster is unplugged & vaccuum is blocked. I have noticed it doesn't do it when the car is cold and when I go backwards.
Any ideas or thoughts would be greatly appreciated.

Thanks,
Rob Mansfield

[TDW]

Air cleaner cover just touching the coil wire when braking? Coil wire loose? The 12 volt wires, not the center coil wire? Bad connection at the horn relay? Ignition switch wire loose?

[PeteLeathersac]

Could the wiring be mixed up where the ignition feed is somehow connected via the under-dash brake light switch?.
The hot/cold difference is perhaps it's own problem but it's possible someone's wired things up so the reverse lights are supplying ignition power while backing up?.
Run a hot-wire + battery to + coil and see if it still happens when you step on the brakes?.

Goodluck!.
[img]<<GRAEMLIN_URL>>/beers.gif[/img]
~ Pete

[SS427]

What about parked, running and the brakes applied. If it still does it then it is likely related to electrical. If not, likely fuel related or like Tony mentioned. I would also experiment with driving down the road and VERY gently applying the brakes though enough to slow the car over time. If it stalls, I would again look at electrical. If it does not, look for fuel related.

[Rob_M]

Well..... I'm a little embarrassed. After checking all the wiring, a friend suggested checking the floats again. Sure enough I had the springs in backwards!
[img]<<GRAEMLIN_URL>>/smile.gif[/img]
Thanks for all of the assistance!

Rob M

[mockingbird812]

Looks like Rick gets the prize. Glad you got it figured out. Nothing to be ashamed about, most of us have been there before! There seems to be a healthy dose of folks 'round here willing to help out a fella when he's havin' issues! [img]<<GRAEMLIN_URL>>/beers.gif[/img]