Read my plugs please

[19dabeast85]

I've had a bit of a rough idle/low rpm start for a long time now and still trying to diagnose it. As per d112crzy's suggestion, I tried ZFR6F11's gapped at .040". I've run them all winter (about 3,000 miles mostly city short drives).

Dizzy has year-old OEM igniter & coil.
NGK blue wires in great condition.
NGK o2 not even 6 months old.
PT6 ecu

Warm compression test performed 2x per cylinder revealed (1-4) 175, 175, 175, 170.

Shining a light and looking at the pistons, every one of them is dry, gray colored, and resemble the texture of a badly rock-chipped bumper.

Sparkplug tubes are 100% dry of oil.

Here's the plugs:

[19dabeast85]

Bump, one of you tuners floating around here knows how to read these!

[wed3k]

yea you can see black specks on the porcelin on number four which indicates a little bit of oil consumption but nothing too big of a deal.

i dont think the plugs themselves are a problem. leak down number 4 and see what you get. it could be a little bit of carbon stuck between the valves. very common.

[GenDBlade]

try a diff spark gap. and check your injectors

[19dabeast85]

I don't personally have a leakdown tester, I'll see if I can find somebody to do it for me or just go ahead and buy one.

When I pulled these plugs I went ahead and replaced them with Denso PK16TT gapped at .040". Engine does seem to run a bit smoother but I still have some vibration issues.

Ignition timing also properly set, fyi.

[93F22A6]

Those are really white, way to white. Something is making you run a little lean. Try cleaning out your tb with some carb cleaner and blowin out your air filter, should help a little. Really there are'nt any thing else I can see.

[wed3k]

Those are really white, way to white. Something is making you run a little lean. Try cleaning out your tb with some carb cleaner and blowin out your air filter, should help a little. Really there are'nt any thing else I can see.

porcelain is supposed to be white bro.

[19dabeast85]

porcelain is supposed to be white bro.

Is he talking about that or the ground straps being very grayish-white instead of a darker color??

[93F22A6]

porcelain is supposed to be white bro.

It should be whit new, but you want that nice light brown color.

[4thgentuner]

19dabeast85 have u replaced n e motor or tranny mounts lately?
chk for seperations at the mounts, maybe culd be causing bad vibrations at low rpms...
wat else i was thinking was to chk ur idle, maybe bring it up a 1/4 turn or maybe a half a turn, adjust it with ur iacv unpluged like the haynes manual says, theres a post here too that shows how to adjust idle...

[19dabeast85]

19dabeast85 have u replaced n e motor or tranny mounts lately?
chk for seperations at the mounts, maybe culd be causing bad vibrations at low rpms...
wat else i was thinking was to chk ur idle, maybe bring it up a 1/4 turn or maybe a half a turn, adjust it with ur iacv unpluged like the haynes manual says, theres a post here too that shows how to adjust idle...

Nothing is wrong with the mounts, all 3 are ESP swap poly mounts and front dogbone has the poly insert. This isn't a chassis vibration, it's an "engine bogging" vibration. My base idle and base ignition is set to spec and the IAC performs correctly.

[wed3k]

It should be whit new, but you want that nice light brown color.

so why do you want a light brown color if it should be white? if anything the electrode should be a light brown color not the porcelain. the plugs look brand new which is healthy.

[93F22A6]

so why do you want a light brown color if it should be white? if anything the electrode should be a light brown color not the porcelain. the plugs look brand new which is healthy.

When they are white it mean your running your motor lean, light brown is good, and dark brown/black is too rich. You also really need to get a shot of the porcelain base in the spark plug.

[wed3k]

is your answer serious?

[Ghetto_CB7]

Sorry

Sorry I am not up to speed with all that you have tried to fix the idle problem. If you could let us know that as well it might be useful.

The plugs themselves look ok for 3000 miles. I see nothing inheritly wrong with them.

Idle seems it could be a little rich, or there is a little oil getting in, but I don't think that would cause a complain-able idle issue as most people on the forum probably have much worse then you, a little rich at idle usually makes it idle better.

What is your timing set at just for the sake of knowing, and if it is stock you may try advancing it one degree and see if there is any improvement in idle.

Let us know what else you have tried.

EDIT: also what rpm are you idling at, if it lopes give a range.