my 91rs 305tbi is acting weird. after driving cross country from MS to AZ, i swaped out my damaged cat, for a straight pipe. the car was running fine. a little tighting of the header bolts, and it was running well. i've noticed with the straight pipe, i've been able to push the car to alittle higher rpm's than before. well, here's the problem. i was about to make a turn, then down shifted from 3rd to 2nd. brought the rpms to about 3.5-4k. then the car just died. it made a loud poping sound, kinda like a back fire, then quit. it wouldn't start, wouldn't turn over, wouldn't do anything. looked under the hood, nothing blew up... waited about five min... then it fired up. drove about 1/2 mile, then tried to down shift again, same result. waited five, then fired up. drove another 1/2, down shifted again, then it didn't do it... what is up? the motor was rebuilt about 15k ago... was bored 30 over, shorty headers, msd wires... i guess that's about it..

 

what kind of ignition do you have?
sounds like an intermittent short in a coil wire or the plug that goes to your hei might be loose?
bad ground somewhere?
Eric B

 

the ignition is stock..

 

chech the contacts to the coil,the plug into the cap,and lool for a dirty ground somewhere(battery,starter,engine ground etc.
Eric B

 

but what would make it just die, out of nowhere.. just from a higher rpm downshift? that's weird.

 

an intermittent loss of power to the ignition would cause the engine to die,followed by restoration of power a second or so later while the engine is pulling vacuum,would cause the backfire you described.
not gospel,but plausible.
Eric B

 

i'm not a great mechanic, nor am i completely stupid. i've done the whole front end along with all around drop springs myself, i am more of a, if it's broke, i can swap it out kinda guy.. not too great on the diagnostics of engine ****.. i don't know a much about the vacuum and how that all works.. could you tell me how to check this problem or adjust it. thanks for your help.. also, how do you get that picture so show up under your name?

 

I've also seen it with the plug wires. they get warm and if the wires are bad sometimes they don't always have the connection
had the same issue with a friend and his 350 tbi.
would drive along once the car warmed up it would backfire through the TBI and you would feel a nice hiccoup. but in this situation the car would keep on chugging after that.
he tested the wires also. they tested fine as can be. but problem went away with new wires.
might want to give it a shot