SR20DET Fouling Spark Plugs

[Edyz7s]

I did intense research on trying to figure out why im fouling out my plugs. I know I am running rich because at idle, it sits at 12.9~13.3 AFR. What I got out of researching, I think im fouling them out when I sit at idle and when I push it hard (Not during cruising, afr around 14s). I daily my 240 but at the current moment I have it sitting because I start having misfires at cold start ups until its warm (wont miss during warm idle)


*I have walbro 255and AEM FPR. My pressure currently sits around 36-38? Hard to tell with the gauge I have it connected with. With out vac, its around 45-46 if I remember correctly
*BOV recirculated and have my BOV on the throttle body side.
*spark plugs I have now are the BK6E-11. I gapped them first at .30 but then started to miss, I then gapped at .28 and was running better but now miss because I fouled them.
*Yaris ignition coils with everything I need to run them correctly.
*I own a blacktop SR with J4 ECU (No Tune)with wiring specialties harness made for my setup.
*Recently changed my O2 (FAT) Knock sensor (ISR) and the harness for it (Wiring Specialties)
*Did compression test: around 120-130s for my motor
*Idles at 850s and jumps to 900s after a couple seconds, this is when afr reads rich
*Base timing is set at 15* (May not be true since my IACV catches slowly)

For the longest of time, I ran NGKs Iridiums gapped at .28 with stock coilpack and had my walbro on since i swapped (3 years). Never fouled nor missed as quick as it does now (current plugs lasted 3 days of daily/some boost driving) even tho I had other problems at the time and ran slow. Now it runs better than ever but the only problem is this

[Kingtal0n]

looks like wrong plugs. BKR7ES is what comes NGK factory but one step colder.

If they foul its rich. needs tuning. Maybe the maf is old.

One time i tried 3 different S13 maf sensors and got 3 different results.

My process would be:
0. compression test. boost leak test. Verify timing accurately.
0.5 get the right spark plugs
1. disconnect O2 sensor to verify open loop fuel a/f ratio
2. tune as necessary / get correct maf as needed

[Edyz7s]

So I got the plugs Kingtal0n suggested, and gapped at .28. I just started her up so we'll see if they'll foul up.
Well I checked for boost leaks and found a few. My bov was one of them, where you adjust the spring(fixed). Then a hose that connects to the vaccum line, had to zip time because it was loose. And a clamp that connects to the ic piping was loose.
I adjusted the fpr while having the pump running by itself with the ignition on, it was above 45 so i lowered to 43 like the fsm says. When running and vac connected, it stays at 33-35 if that says anything. Another thing when i had the fuel pump primed, it would go up and down and you would hear it too..
I checked my o2 by unplugging it and saw it would run richer if disconnected, so thats a sign it would be at closed loop?
Everything else Kingtal0n said is either fine or the same.. but so far i am still running rich (staying in the 13s afr)

[Kingtal0n]

First of all .028" Is very tiny gap intended for racing at high boost, perhaps 15psi or more. The smaller the gap, the less efficiency, the less economy, the less spark is exposed to the combustion chamber, the weaker the burn will start off etc...

I recommend a larger gap 0.035" or 0.033" for example, unless you are blowing out spark of course.

Run the largest gap possible in other words for max efficiency

Now, RICH with O2 sensor disconnected is boost leak or tuning issue.

It goes MAF -> ECU -> INJECTORS.

So either the MAF is wrong, bad, dirty, uncalibrated, old and crusty (ok you get it), OR, the ECU isn't properly interpreting the maf sensor (the tune is wrong).

Or a boost leak. PRessure test the system? YOU need to fill the plumbing with full pressure 15psi+ to test for leaks. If you did this then the next step is merely the maf/ecu tuning. Or fuel is slipping in some other way such as bad injector O-rings.