Stage 5 on OEM plugs?

[Saabonthis]

Just picked up a 99 saab 93 with a JZW stage 5 tune. Has the jakstoll t25/t28 turbo, bigger intercooler, green giants, 3in dp and exhaust. Only issue I seem to be having is after 100+ miles it starts to misfire under full boost (27psi). It goes away when I replace the plugs. I'm wondering, maybe I should switch to a colder or hotter plug? And recommendations?

[Fox Fader]

My first question would be about the tune or maybe ask JW.

You running an A/F gauge?

[Saabonthis]

No a/f gauge yet. That will be one of my first items to get. However, after checking the plugs they are a light tan color.

[saabkid37]

what plugs are you using.

[grkguy89]

^this
AND
what are the plugs gaped to?

[Saabonthis]

Well I just installed ngk iridium ix plugs. They are gapped at .040. New plugs didn't help the misfire/sputter. Drives just fine otherwise, just when you hit 15psi+ it starts to act up. The plugs before were some cheap bosch ones, it ran perfect for awhile. Gap was the same on those as well.

[saabkid37]

It's very possible the non ngk plugs blew up the di cassette.

[Saabonthis]

Anyway I can test the di?

[tomipee]

You should try with another dic

[losacker]

i would go with the original resistor plugs instead of the iridiums. and the gap should be .039, not .040. especially with higher boost you might be blowing out the spark with the longer gap.

[grkguy89]

at stage 5 gap them tighter than that... closer to .033-.034
Im gaped at .030 on my stage 6

[Saabonthis]

I'll lower the gap down a bit and see if that helps at all. Also I do not have a rear o2 sensor. I have replaced the front with a universal bosch. However, I'm getting that p0135 code. I've checked fuse 38, and it's good.

[swedishrocketng900se]

Are u running a red or black dic ? ive heard that for the higher level tunes that t5 should run on the red dic just a thought idk how true it is though

[Saabonthis]

I'm using the red top di

[AZR Racing]

t5 should run the red DIC regardless. you can run the black DIC on a t5 but its not reccomended due to the lack of some components, like a knock sensor. stage 5 tune and no wideband... this is a recipe for disaster. you could be leaning out really bad. does this car have a 3bar map sensor? what color are the plugs when you pull them out.

[bogan]

I run NGK's 7's on my stage 5, Gapped to 0.9mm.

Use the cheap NGK BCPR7ES-11 copper plugs, Our motors love them.

[tomipee]

^i use those too, no problem. Many uses those ngks here in finland, good plug for these engines. Doesnt last for years i think, but those are cheap

[Saabonthis]

Okay, well after checking the plugs, they are a light tan color. Also I turned the psi down to 20psi and put the plug gap at .030 and so far it's not misfiring.

[saabkid37]

Originally Posted by Saabonthis

Okay, well after checking the plugs, they are a light tan color. Also I turned the psi down to 20psi and put the plug gap at .030 and so far it's not misfiring.

time out. if you turned down the boost it sounds like your using an mbc with an ecu tune...which is a no no.

[bogan]

Originally Posted by tomipee

^i use those too, no problem. Many uses those ngks here in finland, good plug for these engines. Doesnt last for years i think, but those are cheap

I change my plugs every second oil change and re-gap every oil change.

Originally Posted by Saabonthis

Okay, well after checking the plugs, they are a light tan color. Also I turned the psi down to 20psi and put the plug gap at .030 and so far it's not misfiring.

Yeah, How did you turn your boost down?