So making a new post from mine before. I'm spraying a zex wet. I have a bottle warmer at a constant 950-1000psi when I spray. I'm running ngk 4554 plugs (range 8). New oem ignition coils and cleaned injectors. No check light and running good. 2002 ap1. I'm also running a aem wideband with a brand new sensor installed this year.

Anyways to my problem I can't find a solution to. My jets were a 55 shot (.017 fuel .032 nitrous). When I sprayed with this, it went straight to rich 10.0 on the wideband. It had a blinking check light and was bogging while on the bottle. I let go quickly after and the check light wentry away. I later scanned it to find previous codes and found out it was a mutiple misfire.

I then switched the nitrous jet to a .036 to try and lean it out. Went for a spin and on the bottle, same thing... bog with a check light flashing. It definitely pulls the first 5-8 seconds then it bogs down and afr goes rich, this time I saw around 12.0 afr. Go home and looked at my bumper. After 3-4 pulls, my bumper was turing a little black.

So im at a lost here. I can only think of 3 options;

1. For some reason I think it's the primary o2 sensor controlling the air fuel. The car has some miles on it for sure. Compression test is good. 235 across and leak down is good. Valve adjustment and new retainers put in early last year.

2. Change the nitrous jet again to lean out the mixture. I do have a .040 jet from the 75 shot that I can use. I'm just worried things might go boom.

3. Go to a dyno and get some pulls in and see what the tuner thinks.

What u guys think?

 

Put your plug gap to .025. I had issues at 50 shot with the spark being blown out. It helps to use copper plugs as well. They are cheap, so you can change them a lot more often.

 

Buying new plugs and gapping to .025 now. Hope it works!

 

New plug old plug. Same ngk. Not even 3000 miles on the old plug. Too much heat? Too rich?

 

And yes I do see the ground electrode is shorter

 

The color of the plug itself looks pretty good, leading me to believe the mix is sound, but im concerned about the electrode and what happened to the rest of it. This contradicts the fair coloring of the plug, and tells me you are seeing detonation or high lean condition melting the electrode. Hope your not causing engine damage. A broken electrode could cause some gulling in your cylinder before its eventually evacuated.

 

Theres a small article on some drag fourms. They said there's 2 ways the electrode will do this. 1. Timing is off 2. Oil is gething in the combustion chamber.

My car has 160k and being a ap1, I suspect oil mixing since I do burn 1 quart every 1000 miles. I think it's time to let go of the kit. Sucks

 

You guys think running a even colder plug would help? Like a ngk 10?

 

the most i've had to go was 2 steps colder from stock

 

I wana give a little update. So I grabbed some ngk 5820 (heat range 10, 3 steps colder). They come gapped at .020. I put them in and switched my jets to the 65 shot. Bottle temp at 1000 psi and did 4 pulls

1st pull in 4th gear the check light was flashing and went away.

2nd pull in 3rd and pulled good. No check light no nothing. Felt good. Afr was 11.6

3rd pull in 4th gear and also pulled good.

4th pull in 3rd gear pulled good no problems. After I let off, the car sounces like it was misfiring. A light jerk for about 30 seconds or so then it went away and drove normally home. No sounds of misfiring since.

Conclusion for this update is that it's running better then before but not 100%. What do you guys think?