rx_treme

iTrader: (9)

What would this plug indicate to you guys?

The plugs were brand new gapped .29 TR6's with approx 70 miles on them. Its a Whiteish coating (very thin) with a blackened base ring. The whiteish coating scrapes off with a finger nail.

The car runs great in vacuum up until 0 vac or boost then stumbles badly.
The tuner (nicD) said everything looks great on the tune and AFR's are good. No codes.

I'll give more details after I finish the compression and leakdown test in a few.

rx_treme

iTrader: (9)

Just got finished with the compression test and leak down.
1-185 2-180
3-185 4-170
5-170 6-180
7-195 8-170
All cylinders less than 5% leak down. although i can still smell the oil smell being pushed up through the breathers on the leakdown test. I can also kinda hear it coming from breathers.

Any ideas?

Anyone else have this problem when going into boost?

I only have two things left to try. A new Map sensor and a fuel pressure gauge to read while driving.

OUTLAWZ RACING

iTrader: (9)

Are u running a maf? If so take a look at it and make sure its clean. Seems like the car loads up on fuel when boost comes in recheck the tune.

rx_treme

iTrader: (9)

No, no maf, but thats exactly what it feels like.
I'm gunna swap the map sensor and throw a fp gauge on it just to see if it changes.

ls1290

iTrader: (20)

The white coating is a good indication you are running lean, way lean. Recheck your tune looking at the PE multiplier.

sevanseriesta

iTrader: (34)

I also agree on way lean, I can not even idle my car for 10 mins right now with out failing to plugs. Put Mine are pitch black... Do you have a A/F gauge? What does it say!

rx_treme

iTrader: (9)

yea Wideband says around 15 at cruise and dips to 12-13 when it starts stumbling at about 0 manifold pressure.
Thanks for the help guys, keep it coming!

crashly

you cannot read a gas plug by just looking at it...
methanol yes, gas no

the thread has to be cut off, and the fuel ring looked at , right down the bottom of the white porcilin.
or
an eye piece , magnifing glass used to look down inside the threaded section

the only thing read on gas plug is the timing mark on the electrode.

ash

hellbents10

iTrader: (10)

Agreed, that and signs of detonation as noted by black spots on the porcelain.

crashly

...and the dreaded tiny ***** of alloy....

rx_treme

iTrader: (9)

So I figured it out.
7 of 8 spark plug wires were burnt/charred/arcing and falling apart.
New spark plug wires and fire boots fixed it.

cablebandit

iTrader: (37)

fire boots cooked the wires on my incon and ofi kit

rx_treme

iTrader: (9)

What do you mean, that the fire boots are what actually ruined your plug wires?