SR Coil Pack Resistance, and also, What's on my plugs?

[jspaeth]

I was regapping my plugs today, because I have been blowing out spark, and they looked like this (about 700 miles on them or so):

http://i947.photobucket.com/albums/ad316/golfertilltheend/Car%20Stuff/PICT0002.jpg


Never in 4 years have I seen any deposits like this on the strap. I trying scraping it off with the tip of a nail, and it came off pretty easily....

I am not leaking coolant, car has power, compression is good, no coolant missing from radiator, no smoke at ALL from tail...

Any ideas?


2) Looking at the plugs, it looks like the 1st cylinder (on the left) is running a little hotter, since more threads are darkened due to heat.

Since I have Power FC, I may try adding about 2% fuel to this cylinder, as it is at the end of the fuel rail and may be leaner than the rest sometimes.

Also, if you look at the strap on the 1st plug, it changes color about 2/3 of the way from the end, so I am thinking timing is okay.

I have read that if the insulating portion around the tip (white) is TOO white (it is supposed to be a little brown apparently), then maybe you have too much timing? However, I don't think this is the case, as people with a lot of experience have seen my timing map, and if anything it is conservative.....maybe the center insulation is still pretty white bc the plugs are only 700 miles old....


3) Finally, I checked coilpack resistance....this was using a SHITTY, old voltmeter.

All 4 came out to around 0.7 ohms, but again, I am uncertain as to how good the meter is.

Question:

FSM says they should be 1 ohm....if they are "weak" or failing, will the resistance be higher or lower than 1 ohm?

[GSXRJJordan]

Gap looks unbelievably close, especially on the second one, what do you have them gapped to?

You'd love for the straps to look clean, but they don't look too bad. Insulation looks great, as long as there's no pitting (doesn't look to be). Don't trip on the resistances, multimeters can't really read fractions of an ohm. If they're old/bad, resistance goes up, not down (unless it's shorted, that doesn't happen often though).

I'd say you're good.

[jspaeth]

Gap looks unbelievably close, especially on the second one, what do you have them gapped to?

You'd love for the straps to look clean, but they don't look too bad. Insulation looks great, as long as there's no pitting (doesn't look to be). Don't trip on the resistances, multimeters can't really read fractions of an ohm. If they're old/bad, resistance goes up, not down (unless it's shorted, that doesn't happen often though).

I'd say you're good.

Used to gap them to 0.032....things were fine....

Then in the fall, I added cams and mani and went from 320 hp stock GT2871R to 19-20 psi and probably around 380 or so (timing and fuel need work haha).

Over fall, winter, spring, I was hitting 20 psi and then tapering down to 16 by redline.

Found a boost leak recently.

Now that I can hold 20 psi all the way to redline, as soon as I hit around 6000 RPM, car sounds like it is missing.

Recently gapped the plugs down to 0.028.....that is what they are in this picture.

Still missing.

It got chilly the other day, and the missing was still there, but not as bad.

Now I gapped them down to 0.024....(CodyAce uses 0.022 and swears by it).

Also just spent an hour cleaning up Intake Mani to chassis, and battery to chassis grounds by sanding the paint off the body and also sanding down the terminals so they are nice and clean.


About to see if that makes a difference.

.................................................. ..........

You really think those straps look okay? In 4 years, I have never seen ANY types of deposits on the straps....

Can you make a guess as to what the hell that is?

No oil on plugs, no coolant as far as i know (good compression, oil and coolant look okay, no smoke of any type....).

Those beige deposits are making me feel weird inside lol

[jspaeth]

So I did some research, and the deposits I am seeing seem to be what is called "ash deposits"

Interpreting your spark plugs (http://www.classictruckshop.com/clubs/earlyburbs/projects/spark/plugs.htm)

See the last picture on the bottom left.


"May be due to additives in the fuel ....."

Recently I installed a new fuel pump, and the fuel pump had some sort of a lubricant or fluid inside I believe (new Walbro).

I am wondering if there was even enough in there that this could have played a role?

[codyace]

I don't think any of the 'lube' issues made any difference - spark plug reading is much like economics...it all depends on how you want to look at a curve ya know?

I do swear by small gap and copper plugs. Seems to work best fo ra street car (but that's not to say that Iridium or Platinum don't work either, like we discussed)

For the most part, I think you're having an ignition issue, but troubleshooting them typically ends in parts changing (as much as I hate to admit it).

Like we said, a higher amp alternaotr and an ignition amp won't hurt, but your's seem to be sufficient. Gap em tighter and lets see.

[jspaeth]

I don't think any of the 'lube' issues made any difference - spark plug reading is much like economics...it all depends on how you want to look at a curve ya know?

I do swear by small gap and copper plugs. Seems to work best fo ra street car (but that's not to say that Iridium or Platinum don't work either, like we discussed)

For the most part, I think you're having an ignition issue, but troubleshooting them typically ends in parts changing (as much as I hate to admit it).

Like we said, a higher amp alternaotr and an ignition amp won't hurt, but your's seem to be sufficient. Gap em tighter and lets see.

Alright, thanks Cody! Like I said, I have run 0.032-0.028 for 4 years with no issues, but this is the first time I have EVER seen ANY type of deposit on my plugs....naturally they should be brownish-grey on the strap, but that should be the COLOR of the metal....this is actually a "film" that is on there that I can scratch off to reveal the metal beneath.

Also, this is the first time (past few weeks) that I have ever had spark blow out on me.

Maybe the blowing out spark is resulting in these deposits?

Knock sensor is saying no knock (and always DOES read knock the few times I actually have).

[jamanrr]

Alright, thanks Cody! Like I said, I have run 0.032-0.028 for 4 years with no issues, but this is the first time I have EVER seen ANY type of deposit on my plugs....naturally they should be brownish-grey on the strap, but that should be the COLOR of the metal....this is actually a "film" that is on there that I can scratch off to reveal the metal beneath.

Also, this is the first time (past few weeks) that I have ever had spark blow out on me.

Maybe the blowing out spark is resulting in these deposits?

Knock sensor is saying no knock (and always DOES read knock the few times I actually have).


Spark blow out will leave dark colored bans across the straps just like that. Car buck really bad when the blowout occurs?

[jspaeth]

Spark blow out will leave dark colored bans across the straps just like that. Car buck really bad when the blowout occurs?


Actually, it pulls hard as hell, and then it kind of starts to sputter a bit, but does NOT buck....it just feels like it's not accelerating at all and the RPMs don't really go up very quickly.

When you say "dark colored bans", are you referring to the "deposits" I mentioned?

....Clearly, a healthy spark plug SHOULD have a "line" about halfway along the strap where it goes from dark to lighter......

[fliprayzin240sx]

What spark plugs are these again?

[jamanrr]

Actually, it pulls hard as hell, and then it kind of starts to sputter a bit, but does NOT buck....it just feels like it's not accelerating at all and the RPMs don't really go up very quickly.

When you say "dark colored bans", are you referring to the "deposits" I mentioned?

....Clearly, a healthy spark plug SHOULD have a "line" about halfway along the strap where it goes from dark to lighter......

Then it is not spark blow out. You will feel a sudden loss of power. Like Cody states it sounds like an ignition issue. Have you checked your grounds maybe go up to a larger gauge ground wire. as can not really tell from your pics but I checked my plugs this evening and they should have a little lite brown mocha tinge on the ceramic towards the top.

[jspaeth]

Then it is not spark blow out. You will feel a sudden loss of power. Like Cody states it sounds like an ignition issue. Have you checked your grounds maybe go up to a larger gauge ground wire. as can not really tell from your pics but I checked my plugs this evening and they should have a little lite brown mocha tinge on the ceramic towards the top.


No, I do feel a loss of power! I shouldn't have said "sputter"

It pulls normally up to around 6K, then all of a sudden, goes "dead" and then catches itself, pulls some more, then kinda "dies"....

So basically it isn't smooth and the power cuts in and out.

[jspaeth]

What spark plugs are these again?

BCPR7ES.

About to try some BK7RE maybe, with the V-power electrode tip....however, these are about 3.5 mm shorter on the plug end....(ISO vs. JIS length)....most people run the BK7RE, but some people have reported issues with the plug not being long enough to make good contact inside the coilpack.

Then it is not spark blow out. You will feel a sudden loss of power. Like Cody states it sounds like an ignition issue. Have you checked your grounds maybe go up to a larger gauge ground wire. as can not really tell from your pics but I checked my plugs this evening and they should have a little lite brown mocha tinge on the ceramic towards the top.


Sorry for the "double response"....I agree with you on the "mocha" tinge on the ceramic....I read that that is GOOD, and that if it is TOO clean and TOO white, then it means you have way too much timing.

However, I KNOW (standalone) that I don't have too much timing, and the straps show that the timing is okay.

I am thinking they aren't yet "mocha" because they are relatively new (700 miles) plugs....

When you say upgrade ground.....are you talking about coilpack harness---->back of head ground?.......or head---->chassis ground?

I don't see how you can upgrade the coilpack harness ground without ripping apart the whole harness.

However, the head to chassis ground should be no problem.

Would it be bad to put one end of the head->chassis ground under the same bolt as the coilpack harness ground, so that the two are making direct contact?

[PoorMans180SX]

Those deposits look white to me. White = coolant.

My 2 cents.

[jspaeth]

Those deposits look white to me. White = coolant.

My 2 cents.


I was thinking that, too, but NO coolant smoke out of exhaust and no coolant missing from radiator at all....and oil and coolant both look good.

[slow92]

My plugs always looked like this. I ddin't think much of it until I went to get retuned for more boost and the car kept breaking up. I narrowed it down to coilpacks so instead of buying new sr coilpacks I upgraded to ls1 coils and my plugs looked great. I don't know if this helps but I didn't have any kind of coolant issues but soon after upgrading the coils my rings went out.