turbo missfire
 

any one faced misfire problem with force induction?

the car misfire @ 4500 @ stand still
miss fire full throttle @ 5000 and no power

we think its the spark plugs? but any idea

hopefully you're running something with a cooler heat range

I agree... try fresh plugs properly gapped two steps cooler. How fresh are yours? Have you taken them out and looked at them?

http://www.ngksparkplugs.com/tech_su...qs/faqread.asp

2 steps colder plugs? Those are going to foul out real quick.
To the op you need to make sure your tune is 100% before thinking its something else, if it is in fact, gap the plugs down to .022. Also if you were tuning it and ran very rich for a while then you might have fouled out the plug. Any vacuum/boost leaks after the maf will also make the car misfire.

Are you tuning on e85, pump or racegas? What boost level are you at?

Two steps colder from the NA plug on a turbo application has worked perfectly for me for many years.

You know the FRS already has a 9 in it right?

Also heat range will depend on Amount of boost and power you plan on running. If you just throw too cold of a plug in it you will just foul them out all the time.

this.

check your logs/tune depending on ecu of choice and pull the spark plugs and inspect then correct the issue causing the problem. if you have fouled your plugs we can hook you up with a step colder plug that we have been using in our turbo setup

What brand of plug are you using?

Going from an 8 to a 7 generally means a HOTTER plug.

That was really bone headed on my part. You are absolutely right. I am two steps colder on the K, but it was from a 7 *facepalm*. Had to check when I got home. Apologies.

If your running 93 on this car your probaley not even going to be running enough boost to need to change the plug to a colder unit. If your running a different fuel and higher boost then yeah you should. Just my 2 cents.

Unless it's E85, then you don't need (nor want) colder plugs.

In the 45 degree celcius heat that you may be trying to tune/operate in, you should be a couple of heat ranges colder

Also, how much boost pressure are you making?

And, what is current AFR in the rpm ranges you mention?


A miss like that doesnt sound great to me, especially on a neutral throttle, I would be having kittens if I was you.

I hardly see these plugs missing. they are a good heat range for turbo, and they come gapped at around .032. That gap is good for quite a bit of boost with a proper high power ignition system and iridium plugs.

On a GT30r type setup I could only see spark blow out after 18psi or so... perhaps running too rich?

but isn't checking the plugs a 4 day arctic expedition on these things?

:-)