jdm12a

so whenever i approach a light or a stop sign and have to take it out of gear it dies, dunno why, its done it like once a week b4, then stopped, and now it does it more often then not. its an 85 12a. i jus put a new exhaust on it about a week and a half ago, but it didnt start dien until the other day. lack of backpressure? its a 2.5" pipe from the first pre-cat back. thanks for the help

rmriggin

do you have vacuum leaks since doing the exhaust? Are emissions still on the car? I know there is an air pipe that goes from the main cat back up to the intake manifold. If that pipe did not get reattached or pinched/welded closed then you might have a vacuum leak on your hands.

GREYBEARD81

I think I know the problem my 81 pulled the same stuff.. The igniter boxes on mine was the problem. The parts houses want an arm and your first born child for the bloody things.. They tell you to change out the both of them, but I pulled on off my 85 parts car, solved the problem.. My 81 is totally stock, so is the cadaver.. The igniter boxes are on the side of your distributor. On the left fender wall inside the engine compartment, the coils are mounted there. Have someone raise the rpm manually then pull one wire, replace it then pull the other, the one that doesn't change anything is the problem child. Be carefull when you disconnect those wires, unless you want your hair to light up and change colors.. good luck Greybeard

diabolical1

first of all, where did you set it to idle? second, you should check for vacuum leaks ... and then check again.

jdm12a

nope, we didnt put that back on and thats what we have figured is the problem

BeaterRX7

http://www.mazspeed.com/diagnosingdr...typroblems.htm



I would especially look for vacuum leaks and check the brake booster to see if the diaphragm's torn.

74rx4

Check the hose going from the #2 anti-afterburn valve to the rear of the intake manifold.



http://intertron.com/ron/carb.html

(click on the first picture for a large view)



This hose often gets melted and develops a hole where you can't see it. It can seal when cold and open up when it warms up creating a vacuum leak. Pull it and inspect it carefully.



http://intertron.com/ron/images/carb/c40.jpg

http://intertron.com/ron/images/carb/c41.jpg



for close up of hose, how it goes bad and how to fix it.