Hi i have a 87 iroc i just changed my plugs wires rotor distributor cover...and fuel pump...But lately its been running a little rough it idles right in the middle of the 10 and 5..but the rpms are always jumping..not alot but like rumbleing alot..i checked the codes but got code 24 which is vss....and code 34 i dont know what it could be but its bothering me cause when i come to a stop its like its rumbling alot any help would be appreciated thanks.

 

check for vacuum leaks

 

i have checked all vacum lines and listened for any and everything checks out...it just like a rumble it shakes alot i have a exhaust but i know its not suppose to sound like that.

 

At night lift up your hood, look for sparks. I have had this problem before.

 

What do u mean look for sparks like spark from the distributor?