Plug gapping w/ TD04

[Threshld1]

Hey i was wondering what you guys though about setting the plug gap to with a TD04 @~9psi after IC on a EJ22T. Ive been experiencing stumbling/missfires under heavy load/WOT for a while now. Ive been through NGK plat's @.035, OE NGK @.040 and ive seated them down to .035. it seemed to clear up a fair amount though it is still present at .035. wondering if its a good idea to seat them any lower?

Also at what point will i peak my stock fuel pump/injectors and how do i know if i am?

[vrg3]

This isn't really an answer to your question, but have you considered investing in a high-output ignition like an MSD DIS-2? The EJ22T's ignition system is the same as the non-turbo's, and seems to be a little underpowered even for a stock Legacy Turbo.

A fuel pressure guage measured against a boost gauge will tell you if you're exceeding your fuel pump's capacity. You may well be close now.

An injector duty cycle meter will tell you how hard you're driving the injectors; 100% is of course the limit, although they start to act funny above 80-85% duty cycle. You may well be close now.

A wideband air/fuel ratio setup will tell you if you're flowing enough fuel overall or not.

[sammydafish]

I'd drop the platinums ang jus get a set of regular copper plugs.. the V-powers work pretty well too and are cheap. Experiment with the gap, it's the only way to know for sure. The gap that works will be very dependant on your effective compression, ignition and boost efficeny (turbo+intercooler). You'll notice that with upgraded coils/DIS-2 you can open the gap up a bit again without missfires and gain some fuel economy and throttle response.

Remember that you can order NGKs to gap too. The last two digits of the part number is the gap in mm. stock plugs are -11 or 1.1mm gaps. You may want to experiment with plug temperature too. For NGKs the higher the number the cooler the plug. Pretty sure the stock plug is a 6 heat range.

[vrg3]

A colder plug won't resolve misfires. It could make them worse though.

[Threshld1]

ill keep upgraded ign. in mind once the budget allows. im prolly going to combine that with the wideband and other aftermarket EM stuff to coencide with bigger injectors.

I took the plats out and got some plain old flat ngk coppers and they are running better than the plats. i get a good discount at napa so the cost was only $2 a plug for plats so its not a big deal. I might swap the current ones to v-power in the coming weeks for fun.

Im thinking my hessitation issue is related to a leaky intake gasket on #1-3 as there is a fair amount of liquid residue around it and not on the #2-4 side