i have a 89 Iroc tpi setup and over the past few weeks ive gotten it to run fairly well but it still backfires. Ive got new plugs wires cap rotor O2 sensor and a few odds n ends, its timed to 6deg and i just cleaned the IAC wich greatly helped the fast idle.

but anyways drivin it around today it was runnin good (not great, its still lackin a bit of power) and after about 45 min it started backfireing. so if anyone has some suggestions im up for em

thanks

 

Backfire from the intake is lean, Backfire into exhaust is rich.

 

Timing chain jumping can cause that too so I've heard.

 

my back fire is comming from the exhaust so i would be runnin rich. isnt it the O2 sensor that helps decide the fuel mixture. i just replaced the one thats in there now, is there a way to test it to check if its all right. or is there another sensor that i should be woried about for the fuel mixture. i do notice a faint unburnt fuel smell every now and then. thanks for the help peeps, ive been reading the forums but without a search function curently its hard to find what im lookin for

 

My car did this one day, with no SES codes. About an hour later it threw a code 34 (MAF). And when this happens, the ecm makes the exhaust super rich. Rich enough where its blowing black smoke at idle.

 

check your ignition coil i had a cheap coil on my car thing was backfireing like crazy change it out for a better one and its fine.

 

so i tested my coil and it failed one of the tests. i installed a new one and it greatly helped with the backfireing, i only get small pops everynow and then, before i was gettin bangs (i actually had a backfire that blew a hole in my muffler) that shook the car. the new coil didnt help with the unburt fuel smell though

so i guess my question is would a faulty MAF give me these problems, or something else, the MAF i have on there looks like its brand new (its the only thing under the hood with stickers) but its a bosch. im not to sure about bosch stuff i usually get delco for my cars, does bosch make a good MAF