Engine Stalling when Braking

[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]

[TDW]

Glad ya got it fixed Rob. Are any of you Kazoo guys heading to Flint for the &quot;Back To The Bricks&quot; next month? Should be a real good show again.

[Rob_M]

Hey Tony - Probably not this year but I have heard good things about it. I will be at the Grand Rapids cruise though. I've been there every year since it started and it gets bigger every year. I usually park my car at Berger Chevrolet.... I've been to the Woodward cruise and I think the Grand Rapids one is bigger!

[Rob_M]

Well I was/am a little premature on the success of my repairs. The car is really doing it now - Every time I hit the brakes the engine dies. I bypassed the ignition switch in the dash but no luck. I went around the whole car while it was running and shook wires including under the dash but nothing.

I also installed another carb that I had, and the car still died while braking.

I have a MSD box and distributor so I'm wondering if I need to find another distributer to test that out.....

[njsteve]

Did you disconnect the brake light switch to see if the car still dies when the brakes are applied? Could be a 12v wire crimped against the firewall by the brake bracketry - when you apply the brakes, the bracketry shifts and grounds the wire and backfeeds the car into a 12v positive ground system.

When I pulled my 69 Z11 pace car apart I found a main power lead wire from the dash harness clamped between the brake/clutch pedal assembly and the firewall. It would have eventually caused one helluva electrical fire.

Also, one of the brake light bulb assemblies themselves could be internally shorting to ground when the power goes to the bulb. From experience I know the Mopars are extremely sensitive to a bad ground on the tail lights - so bad that they backfeed all the other lights in the car when the brakes are applied, if the ground is not good enough.

[PeteLeathersac]

What happens if you try starting the car while your foot's on the brake pedal?.

[img]<<GRAEMLIN_URL>>/dunno.gif[/img]
~ Pete

[x Baldwin Motion]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: PeteLeathersac</div><div class="ubbcode-body">What happens if you try starting the car while your foot's on the brake pedal?.

[img]<<GRAEMLIN_URL>>/dunno.gif[/img]
~ Pete
</div></div>

Has the motor and trans been out recently? Sure sounds like some wire is being pinched somewhere during deceleration. Check all wires around back of motor, top of trans, starter, exhaust. What type of trans ? Sure is a puzzler. [img]<<GRAEMLIN_URL>>/hmmm.gif[/img]

[Rob_M]

The engine does NOT stall when I use the brakes going backwards, but it does stall when I use the parking brake to stop when going forward. That basically eliminates the brake light switch theory. I did check for any wiring interference and I didn't see any. I also checked the wires while the car was idling - shaking them and so forth and nothing. The car idles just great!

As an example, our driveway is at the top of a hill and if I let the car go backwards and hit the brakes it doesn't stall. Here's the interesting part, if I am going backwards and goose it a little the car dies. This strongly suggest that this problem only happens when the car is accelerated in one direction. Going in reverse and hitting the gas produces the same 'motion' (the car and occupants being accelerated toward the front of the car), while going forward and braking.

When I am driving the car and put it in neutral I can pump the brakes and the engine will start to stall and recover each pump that I do. When it is idling I can hold the brake pedal all day long and the car does not die. It also starts with my foot on the brake pedal.

I know this hard to believe but that is what it does......

I wired the MSD box into the battery, bypassing the rest of the car and it still does it. I assume that only leaves the ignition part at fault. One thing I did noticed is my MSD Blaster coil is mouinted sideways with the bottom of the coil facing the front of the car. I plan on trying a different coil to see what happens. After that I will reinstall my old distributor. (I installed a new MSD ignition this spring...)

At this point I'm just trying everything that sounds logical....