View Full Version : poping when engine not run for a while

08-14-2002, 11:03 PM
ok spark plugs gapped to .030 they are denso iridiums. timing is at 16 degrees. s13 redtop in 89' hatch. this happens when the car has not been runing for at least 5-6 hours. taking about 1/2 hour for the backfiring to go away and will only do it under a quick wot. i can bring it to redline no problem, i just can't punch it. what i cant understand is it will not backfire when i put the ngk r's back in. and if the denso's are gapped to wide why would the backfiring go away after a period of driving? bad MAF? need help on this guys i am out of ideas, thanks.

08-15-2002, 10:55 PM
how you say...bump

08-16-2002, 01:29 AM
possibly bad power to your ignition
make sure you have a good solid connection at the battery plug area for that thick blue/red wire. I had this same problem as well. just make sure its a CLEAN connection to the black/red wire. Also, make sure you have good gas in the car.
if you are doubting the MAFS, check it out, try swapping with a buddy, make sure connection is good.

08-16-2002, 09:28 AM
Its something to do with the acutal spark plugs internal resistance and how quickly it fires the spark, in essence even though manufacturers dont tell you this , different spark plugs alter ignition timing by one notch.

Ive seen a prelude at my mechanics not move once iridiums were put in , and when i had platinum sparks put in my car , the car would almost switch off at the lights due to bad ignition timing , i think we had to retard it one notch (cant remember now)
the reason is because copper is a better conductor the spark is fired as soon as the signal is sent, whereas say platinum is a tiny bit slower to shoot it its the equivalent of advancing your timing.

(i think i got it right ???)

Anyhow thats the reason , ive seen it on lots of cars.

In your case i would be led to believe after 4 hours of driving the metal heats up and its resistance changes.

08-16-2002, 12:13 PM
both very good points thanks guys, did not think of either will give them a try! http://forums.freshalloy.com/ubbthreads/images/icons/smile.gif