First time posting, hello.
Recently i just replaced my topend on moter(1.5weeks ago) heads,cam,intake, so ya...well anyway, today my 69 camaro with 350(should be in mid to low 400crank when its tunned) started running really bad and dieing under anykind of hard brakeing(running alright other times sept during and right after brakeing Granted if its like 50+ i dosent seem to have a problem, but from 30 or less a semi hard break will kill the engine.

What would you think could be the problem?
Also when its about to die, the tach jumps around(as much as going from 2k to 4k) but it dosent feel/sound like the moter is jumping that much. I also have a sinking feeling that i killed my TQ (i was planing on changing it out from the stock soon) , any way that could be causing it?(and it happens even if i put the car in nuetral and brake

Thanks for any help on this

 

Crap, I thought I knew what it was... until you said it does it even when you put the car in neutral and brake. So you're saying it happens even when you brake and the car isn't moving?

 

Nope, when the car is stoped i can push all the brake down all the way in or out of gear w/o problems. But if im rolling at like 20-30, take it out of gear and into neutral(its an auto) and give it much brake it still tries/does die.

 

If you are carbd, check the float level.

 

Thats what I was thinking.... Float level is most likely too low... Do you have a holley???

 

Its an unadjusted edel 600cfm electric choke(have had for 5months)..i had asumed it would be to low, but ran fine for the first week and half after redoing the engine.
Was at the dyno today(no time for tunning anything but advance) and ran ****ty #'s(199/225 ) but by looking at the chart and talking to people there they say prob due to fuel pump and possably carb adj like was said(i dont like tinkering with it myself so will have friend do the carb) as it was fairly flat most of the run.
On the way back after the car started running very ****ty, but if the carb setting ran fine for over a week befor, could the being to lean cause it now? And with that heavy breaking causing eng to die, but ok with a slow stop, still be caused by the carb?

 

Yeah under a hard breaking with the float level low the fuel will move to the front of the bowl causing fuel starvation.

 

Yah, that was my guess too.. kinda threw me off when you said it happend in neutral.

 

I think that's pretty much an edelbrock carb thing.. My 81z did it when you hit the brakes real hard, or turned left real hard...... When I read your first post, I knew right off that you had an edelbrock carb.....