these ? are for a 84 351w
where is the timing plate(with the degrees btdc)?
does the computer control the fuel mixture above idle?
how do you adjust the idle mixture on those little screws on the front of the carb?

 

 

What model carburetor do you have? The part no. should be the air horn if it's a 4-barrel carburetor--something like F4TE 9510 ATA List 60252 1234.

John

 

The timing marks are on the harmonic balancer and the pointer is mounted on the passenger side to the timing chain cover. I doubt that your carb is controlled by a computer, but I understand that in some rare cases they did have some that were that did not work very well. There probably is not any wiring going to the computer from the carb...to set your idle mixture and you don't know where you are, turn the screws all the way in and then back them out 1 1/2 turns, from there you have to adjust to sound and if your exhaust is running black, etc., but 1 1/2 turns will get you in the vicinity.

 

the carb tag is missing but its a 2150 carb. if the comp doesnt control the carb then why is there an o2 sensor? right now cylinder 1 fires 180* away from the timing marker, it pings bad too

 

You must have an EECIII (look on the emissions sticker). The timing is computer controlled and you probably have a bunch of wires going to the carb. Another way to tell is your dist doesn't have a vacuum advance can on the side. Nobody likes this system because nobody knows how to work on it (including me). Most people rip everything off and go conventional duraspark II dist and ignition and put a little edelbrock or holley on it with a 4 barrel manifold.

 

The O2 sensor is for measuring the exhaust gases. The computer uses these measurements to advance or retard the timing for optimal ignition firing. You can also use the O2 sensor for tuning the carb if you have a multimeter. The sensor produces milliamps which youmeasure to identify your best mixture. Here is a link to explain it. http://www.bob2000.com/carb.htm

 

when does the choke get voltage to open? cause today it was about 57* with rain and the choke wouldn't open after running the engine for more than 10 min.