Hey people i gotta 92 firebird vert with 305 tbi...today i decided to do a tune up which needed to be done desperatly...today i changed the cap, rotor and spark plugs....the old spark plugs were worn out pretty bad (white residue on J-hook on all 8)...so i replaced them with bosch platinum 2's...i also did the cap and rotor....the rotor was so damn hard to get off that i needed to chip it off then try prying it off like 50 times before it actually came...like it was melted on or sumthing...as far as changing the plug wires...tomorrow im gonna do that....but while i was doing the tune up...my friend notice a vacuum leak right behind the TBI unit...(kinda near the distribuitor) it looked like it didnt go anywhere i couldnt find a spot for it so i didnt really mess with it....so my question is after i changed the plugs cap and rotor....the can idles bad...i hear a knock in it sumwhere (like a ticking noise) at a red light....do u think its from not changing the plug wires or wut?? Maybe timing can be off....or is it from the vacuum leak??? Where does this vacuum line go all i can hear it doing is sucking air....when the car was idling it was sucking in alot of air thru the leak...but when i covered it the idle went down should i plug this vacuum line?.....I jus dont understamd y at idle my car is acting up all of the sudden is it the leak or the plug wires or timing?? i dunno please help

 

That vacume line just hanging there sounds like the one that hooks to the botom of the stock are cleaner. Plug it and the car will idle correctly and it may help with your problem.

 

Fix that vacuum leak, check your timing, and double check your wire routing. That vacuum port on the back of your TBI is to your MAP sensor and it is vital that it is working and plugged in. Yanking on the rotor like you described could have thrown your timing off. Ladst but not least double check that you put all of the spark plug wires back on in the right order.

 

for the vacuum leak plug it or is there a connection i gotta look for?

 

You should look for a connection. There should be a vacuum diagram on the inside of your hood. Try to trace all of the vacuum lines you can (if you already did this, sorry, I just wanted to make sure you knew). Since it is a line, it has to connect somewhere.

I wouldn't plug it yet because if it connects to a sensor your car still won't run right.

 

Correct. You need to follow the lines off of your TBI unit and see where they go. There is only 5 of them so it cannot be that hard. PVC, EGR, MAP, Thermac, charcoal.

 

you could have mixed up some wires when putting the new distributer cap on.. check your wires see if they are in the correct order. that could cause the car to run crappy

 

put new plug wires on...thats he problem...old plug wires were shot needed to be replaced...car idles great drives even better....only thing weird i noticed driving home...(sometimes when its really cold out) the "service engine light" came on it usually does this when its cold outside for some reason...but car was still running great...any thoughts??

 

I would find out what he code is and report back.

 

Firebird,

Do you know how to pull the codes?

 

believe u connect 2 wires together...i have friends that know how....i hear is simple??

 

At the diagnostic port, the top two pins on the right. They actually are labeled backwards F E D C B A. Put the ends of a paperclip, one in A and one in B. Then turn the car to the on position (don't start it). The fan should come on and your check engine light will start to flash. It will flash once and pause and then twice and pause. This is code 12. It means that you are in diagnostic mode. The next set of flashes will be your error codes. It works the same way. If you have an error code 33, it will flash 3 times and pause and then 3 more times. Jot them down and then look them up in the tech data page here on t he site. When it has no more codes to flash it will flash a 12 again and start the codes over.

Good luck.

 

MAN!!! And I went out and bought a 20$ GM code reader. Here I could have just snagged a paperclip from work. Ah well..