Spark blow out?

[SebringLX]

Hopefully this is the right section for this...

I think I am getting spark blow out. I don't know much about it, but this is what happens... With it holding ~19psi, in 3rd gear when I get to about 4700rpms, the car back fires (pop pop!) even though it was running rich, so I immediately let off the gas. I recorded it doing this, and what I see is I lose about 700rpms when it happens. Runninc rich, steady rise in RPMs, hits ~4700rpm, then rpms drop to ~4000, followed by a lean spike, then I let off.

So I decided to lower the boost a little. I dropped it down to ~14psi and aside from running a little rich, I had it close to 6000rpms @ over 100mph before I let off with no problem.

That means I'm experiencing spark blow out around 19psi right?

My ignition system is an MSD DIS2+, MSD Blast Coil, MSD Spark Plug Wires, and NGK Iridium IX spark splugs.

I do not remember the model number or heat range on the spark plugs. I also have no idea what they are gapped at. I bought them and had them installed over 2 years ago. They only have about 5000 miles on them. I do remember that I go them in preperation for the turbo, and I think I ordered the same part number that the SRT-4 uses.

If I'm not mistaken, to fix spark blow out, I need to reduce the gap on the plugs right? Can I use the plugs I have, or should I get new plugs? What should the gap be? My turbo is supposed to flow a max of 51lb/min, and I want to be able to run at least 23psi (eventually 26psi).

[SebringLX]

If I'm on the right track here, I want to stop by the parts store and get a spark plug gapping tool on my way home... looks like they are only about $2..

[turbovanman²]

If you blow the spark out, it acts like a mild misfire, hesistation.

Depending on your gap, the setup you have should be ok, so I would check what gap you have and take out .005"

DO NOT bend up the ground electrode prying on the center elecrode if you have to widen the gap, you will break off or bend the iridium center piece.

[cordes]

I would certainly check the gap in the plugs.

[SebringLX]

If you blow the spark out, it acts like a mild misfire, hesistation.

Depending on your gap, the setup you have should be ok, so I would check what gap you have and take out .005"

DO NOT bend up the ground electrode prying on the center elecrode if you have to widen the gap, you will break off or bend the iridium center piece.

Like I said, I lose a whole 700rpms with a quick pop pop when it happens... however turn the boost down and it goes away, makes me think it's spark blow out.

Widen the gap? Shouldn't I be making the gap smaller to get rid of this? I've never gapped my own plugs before... didn't even install these because my stock plugs were stuck when I replaced them... I couldn't get them out so I took it somewhere.

[SebringLX]

One more question comes up after finding this: http://www.ngksparkplugs.com/techinf...stallation.asp

I don't have a torque wrench... I suppose I need to get one if I'm going to do this myself?

[turbovanman²]

Like I said, I lose a whole 700rpms with a quick pop pop when it happens... however turn the boost down and it goes away, makes me think it's spark blow out.

Widen the gap? Shouldn't I be making the gap smaller to get rid of this? I've never gapped my own plugs before... didn't even install these because my stock plugs were stuck when I replaced them... I couldn't get them out so I took it somewhere.

I didn't say widen them, I said reduce the gap by .005" but if you have to widen them, don't lever the ground electrode on the center electrode.

One more question comes up after finding this: http://www.ngksparkplugs.com/techinf...stallation.asp

I don't have a torque wrench... I suppose I need to get one if I'm going to do this myself?

You don't need a torque wrench, tighten snugly.

[SebringLX]

I didn't say widen them, I said reduce the gap by .005" but if you have to widen them, don't lever the ground electrode on the center electrode.

Gotcha... looks like these plugs came gapped at 0.052, I doubt the place I had install them out in MT over 2 years ago touched the gap, so chances are they are still gapped at 0.052.

If they are still at 0.052, taking them down by 0.005 would put them at 0.047, is that going to be small enough? Looks like a lot of the SRT guys run theirs around 0.035, even on their stock turbos. I should be getting a little more powerfull spark from the DIS2+, which should allow a little but larger gap, but how much?

You don't need a torque wrench, tighten snugly.

I don't know, I have a bad habbit of over tightening things.

[Dodge Aries K]

.052 is too much even for the stock engine that came in that car.

I'd gap them at the .035 that the SRT-4 people use... possibly .040 (which is what I run the Neon's gap at) but no more than that.

[cordes]

Gotcha... looks like these plugs came gapped at 0.052, I doubt the place I had install them out in MT over 2 years ago touched the gap, so chances are they are still gapped at 0.052.

If they are still at 0.052, taking them down by 0.005 would put them at 0.047, is that going to be small enough? Looks like a lot of the SRT guys run theirs around 0.035, even on their stock turbos. I should be getting a little more powerfull spark from the DIS2+, which should allow a little but larger gap, but how much?



I don't know, I have a bad habbit of over tightening things.

Get a torque wrench. Also, don't go cheap on one either. If I had to do it again, I would rather spend triple the money than have the ones I've got.

[BadAssPerformance]

.052 is too much even for the stock engine that came in that car.

I'd gap them at the .035 that the SRT-4 people use... possibly .040 (which is what I run the Neon's gap at) but no more than that.

+1, where did .052" come from? That sounds high for a turbo 4 banger.

Also, why Iridium? I have heard issues with fancy platinum, etc plugs with MSD boxes... too much current for the plug magic to work or something?

Regular NGKs work fine for me... I think mine are gapped at .035"?

[SebringLX]

+1, where did .052" come from? That sounds high for a turbo 4 banger.

Also, why Iridium? I have heard issues with fancy platinum, etc plugs with MSD boxes... too much current for the plug magic to work or something?

Regular NGKs work fine for me... I think mine are gapped at .035"?

0.052 is just what they come gapped at out of the box from NGK according to NGK's website. I don't know what they are actually gapped at, won't know until I pull them out and check. I'm just saying I wouldn't be suprised if the stupid local shop out in MT did not gap them before putting them in.

I've heard of lots of issues with the Platinum, but haven't heard of any with the Iridium. Iridium is supposed to be better and last longer than Copper. I ran Iridium IX plugs in my old truck and was very happy with them. I'll run them in my new truck when it comes time to change the plugs too.

I'll take some pics of the plugs when I pull them out this weekend. If I can get them out.

[cordes]

0.052 is just what they come gapped at out of the box from NGK according to NGK's website. I don't know what they are actually gapped at, won't know until I pull them out and check. I'm just saying I wouldn't be suprised if the stupid local shop out in MT did not gap them before putting them in.

I've heard of lots of issues with the Platinum, but haven't heard of any with the Iridium. Iridium is supposed to be better and last longer than Copper. I ran Iridium IX plugs in my old truck and was very happy with them. I'll run them in my new truck when it comes time to change the plugs too.

I'll take some pics of the plugs when I pull them out this weekend. If I can get them out.

Why wouldn't you be able to get them out?

[SebringLX]

Why wouldn't you be able to get them out?

Going to depend a lot on if I can find my spark plug socket. Haven't completely unpacked all my garage items from my move yet...

[TurboTurismo]

The Regular NGKs also work well for me! running 3 bar and D-Cal @ 24 psi..Gap set to 0.35, stock coil, taylor wires with no issues at all ..

Robb

Proud OSDAC Mod & Member
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84 Plymouth Turismo TURBO
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[cordes]

Going to depend a lot on if I can find my spark plug socket. Haven't completely unpacked all my garage items from my move yet...

That's got to be a nightmare. I packed and moved my firearms and tools myself.

[turbovanman²]

Iridium is the best turbo plug out there, they don't melt and last forever,

Try .035" and you still might have to make it smaller. IF they truly are at .052, no wonder your blowing out the spark,

[SebringLX]

Ok, so they were all at 0.045, I gapped them all down to 0.034, only because my tapping method seemed to get them right to that and not the 0.035 I was aiming for. I decided to just go with 0.034 instead of trying to pull it back out to 0.035. So now all 4 plugs are gapped at 0.034.

Here's a pic of one of the plugs, they all look the same:


Turns out I did not get the SRT-4 part number, I actually got the part number for my car. The part number on all of them was LZTR4AIX-11, which is stock # 2313.

The SRT-4 part number is LZTR5AIX-13, stock # 2314. I'm thinking I should eventually switch to this part number, maybe go a step colder.

So the plugs I have right now are actually a step hotter than the SRT-4 plugs... not sure how much that is hurting me if at all.

Car feels a little more responsive now, even seems like I'm spooling faster, but it's actually running even richer than before. I was sitting at 10.4-10.5:1 @ WOT before re-gapping. After re-gapping it's pegged at 10.3:1 and sputters. Time to try and take more fuel out I guess.

[Ondonti]

I would change the plug temp. Its not going to hurt performance but it can hurt the pocket book if something fails

I was getting spark blowout and thought I killed my engine. It probably feels much different in an auto. In my 5 speed it felt like I locked up the brakes for a split second. Thats bad blowout. Blowout starts long before its noticeable on the road. Light blowout can really only be noticed by a dyno.

[turbovanman²]

Change your plugs, your increasing the chances of detonation. Going hotter is bad,

I would run the SRT plug but one step colder.