Strange hesitation between idle and 3000 rpm

xxsurvivalism

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And no, you don't require plugs that are one step colder. VMP ran a lot of tests , and colder plugs are only required once the boost exceeds 10.2 psi. I only have 5.8 psi boost. Plugs are gapped at .035". For a NA car, plugs are gapped at .060". With 9 psi, plugs are gapped at .032".

Right on, found Brisk 3VR17YS. Much appreciated, I'll order them and see how it goes.
 

06 T-RED S/C GT

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I use Brisk plugs on my 2010 GT automatic...+ Roush M90 blower. And no, you don't require plugs that are one step colder. VMP ran a lot of tests , and colder plugs are only required once the boost exceeds 10.2 psi. I only have 5.8 psi boost. Plugs are gapped at .035". For a NA car, plugs are gapped at .060". With 9 psi, plugs are gapped at .032".

I did notice asap, that with the new plugs installed, the misfires dropped to ZERO. I monitor misfires on the aeroforce gauge, plugged into the OBD port. It resets to zero, with eng off. Typ I would get 6-9 misfires every time I used the car. With the new brisk plugs, zero misfires. Runs like a swiss watch. Correct Brisk plugs are not overly expensive.
I beg to differ. Saleen and JDM engineering both require that plugs are one degree colder for the Saleen series VI 475 HP upgrade kit. And yet my boost levels don't exceed 7.5-8.0 psi with 39lb. injectors, 3.6" pulley and Autolite HT0 plugs gapped at .030" with only 7.5 psi and JDM 91 octane tune.

Perhaps VMP's test results claim that one degree colder plugs are only required when boost levels exceed 10.2 psi. However, when it comes to potential misfire issues related to engine detonation due to excessive heat, elevated cylinder pressure from running FI applications? there's obviously a very good reason the SC manufacturer recommends running one degree colder spark plugs. That being said, I haven't encountered any misfire related issues from running one degree colder spark plugs at all :shrug:
 
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Pentalab

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I beg to differ. Saleen and JDM engineering both require that plugs are one degree colder for the Saleen series VI 475 HP upgrade kit. And yet my boost levels don't exceed 7.5-8.0 psi with 39lb. injectors, 3.6" pulley and Autolite HT0 plugs gapped at .030" with only 7.5 psi and JDM 91 octane tune.

Perhaps VMP's test results claim that one degree colder plugs are only required when boost levels exceed 10.2 psi. However, when it comes to potential misfire issues related to engine detonation due to excessive heat, elevated cylinder pressure from running FI applications? there's obviously a very good reason the SC manufacturer recommends running one degree colder spark plugs. That being said, I haven't encountered any misfire related issues from running one degree colder spark plugs at all :shrug:

There are loads of stangs with 8-9 psi..and normal heat range plugs. For piece of mind, you might be correct. Brisk warns about using plugs with 1 degree colder.... when they are not really required. IF the car is used in winter time, and 1 deg colder plugs used, it could causes issues in some cases.

I didn't see anything on eatons site about using 1 deg colder plugs on any of their PD blowers. Didn't see anything on Roush's site either. But I may well have missed it.
 

Oliver Vigil

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For sure, couldn't hurt!

Question: Has Motorcraft updated their plug design at all or are they STILL selling 2 piece plugs prone to breaking?
I believe they discontinued it, but still be careful and ensure to apply anti size per spark plug manufacturer recommendation. Also, the larger issue at hand is probably your spark gap, but new colder plugs would be a great addition to the power you're making. I just went to the Dyno last week, making 7.6lbs and replaced my plugs with Motocraft. Noticed the same issue you describe. Tuner, a well known and go to mustang guy here in town, told me the plugs aren't known for holding up when you introduce boost. So, ensure your new Brisk plugs are gapped between 32 and 35 thousandths and I'm sure you'll see a difference.
 

Midlife Crises

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Interesting reading opinions about what plugs to use. I’m running Brisk Racing plugs two ranges colder than stock. Gapped at 0.030” and I have no issues I am aware of. Never fouled or burned a plug. Does not sputter or cut out at the top end. Starts and idles fine. What am I doing wrong?
 

crjackson

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Didn't see anything on Roush's site either. But I may well have missed it.

I ordered a new Phase 3 Kit from Roush. It included the colder Motorcraft plugs and they were gapped at 0.032 - 0.035 (I can’t remember exactly which gap).

I considered getting Brisk plugs based on recommendations I’ve read on this forum, but there are so many bad reviews about the plugs being defective, and coming apart, and damaging engines (even NA applications), I decided just to stick with the supplied plugs.
 

06 T-RED S/C GT

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For sure, couldn't hurt!

Question: Has Motorcraft updated their plug design at all or are they STILL selling 2 piece plugs prone to breaking?

Motorcraft's plug design for all 2005-early 2008 3v models remain 16mm high-thread 2-piece design spark plugs. Ford didn't change the design until the 3v heads were revised for all 2008 models manufactured after November of 2007. If your car has black coil boots? you have the 16mm high-thread 2-piece spark plugs. If your car has brown coil boots? you have the revised 12mm standard one-piece spark plugs.

The two piece plugs were discontinued in 2009.http://www.agcoauto.com/content/news/p2_articleid/120

The two piece design spark plugs were revised only for all 2008 and up models manufactured after November 2007 which Ford revised the 3v head design to fit standard 12mm one-piece spark plugs. Prior to the head design revision of November 2007, the spark plug design for all 2005-early 2008 3v models from Motorcraft and Autolite are still manufactured with the same 16mm high-thread 2 piece spark plugs. The only one-piece design plugs for the 2005-early 2008 3v models are manufactured by Brisk Racing, Accel HP Copper, Champion and NGK.

There are loads of stangs with 8-9 psi..and normal heat range plugs. For piece of mind, you might be correct. Brisk warns about using plugs with 1 degree colder.... when they are not really required. IF the car is used in winter time, and 1 deg colder plugs used, it could causes issues in some cases.

I didn't see anything on eatons site about using 1 deg colder plugs on any of their PD blowers. Didn't see anything on Roush's site either. But I may well have missed it.

According to Saleen, Brenspeed and JDM engineering. One degree colder spark plugs are required for Saleen series VI superchargers with 475 HP upgrade package which my car has. If the attached link allows to open? Here's the Saleen series VI 475 HP upgrade owners manual which recommends installing Autolite HT0 spark plugs.

https://www.soec.org/manuals/supercharger/mustang/10-8002-C14338C.pdf

I believe they discontinued it, but still be careful and ensure to apply anti size per spark plug manufacturer recommendation. Also, the larger issue at hand is probably your spark gap, but new colder plugs would be a great addition to the power you're making. I just went to the Dyno last week, making 7.6lbs and replaced my plugs with Motocraft. Noticed the same issue you describe. Tuner, a well known and go to mustang guy here in town, told me the plugs aren't known for holding up when you introduce boost. So, ensure your new Brisk plugs are gapped between 32 and 35 thousandths and I'm sure you'll see a difference.

As mentioned above, Ford/Motorcraft did not discontinue the 16mm high-thread 2 piece design spark plugs for the 2005-early 2008 3v models.

The spark plug design wasn't revised until Ford re-designed the 3v heads for all 2008 and up models built after November 2007.
 

06 T-RED S/C GT

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As previously brought up, Ford finally addressed the issue by re-engineering both the 3v heads and spark plugs for 2008 models and up built after November 2007..

IMHO, Ford should had engineered the 3v heads designed specifically for standard 12mm spark plugs from the very beginning. With that said, I most definitely agree that Ford does in fact do some really bone headed stuff lol. Perhaps for whatever reason, Ford didn't think that just changing the design of the older spark plugs was worth the additional investment costs involved towards re-engineering and re-manufacturing :shrug:
 

06 T-RED S/C GT

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xxsurvivalism

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I pulled the plugs yesterday, they actually looked pretty great. They're only a few months old though. Went for a drive today, shut off the car and it sat for 30 minutes. Fired it up, let it idle for 2 minutes, went to take off, and it sputtered and hesitated reeeal bad. Fell right on it's face, almost stalled again. Even revving it in neutral, it was hesitating to climb the rpm band. So weird. And frustrating. Again, ran great after it went away.

Brisk Plugs should be here today or tomorrow.
 

Dino Dino Bambino

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As I suggested in an earlier post, check for a vacuum leak. It sounds like there's unmetered air getting into the engine that the MAF sensor isn't seeing. If the engine runs better with the MAF sensor disconnected, it'll confirm my suspicion.
 

xxsurvivalism

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I'll go do a fourth or fifth inspection this morning, couldn't hurt lol. I unplugged the MAF, idle jumped up. Plugged it back in, the car died.

MAF and TB are clean. What are the chances of a bad MAF?
 

06 T-RED S/C GT

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Just as Dino suggested, it's either a vacuum leak or the MAF sensor has gone bad. If the idle jumped up after disconnecting the MAF sensor and then died after plugging it back in? I would lean towards the MAF sensor :shrug:
 

xxsurvivalism

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Just as Dino suggested, it's either a vacuum leak or the MAF sensor has gone bad. If the idle jumped up after disconnecting the MAF sensor and then died after plugging it back in? I would lean towards the MAF sensor :shrug:

Funny thing about the maf. When I bought the car, it was running rough. After pulling stuff apart for routine maintenance, I noticed the maf was installed backwards. Don't know how long it was run like this, but I have a hunch it was quite a while. Maybe running it backwards for thousands of miles killed it.

I'll check for vacuum leaks again, go over the diagram with a fine tooth comb. Hopefully I can find another maf to try or buy a Motorcraft maf for an arm and a few legs lol
 

xxsurvivalism

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Small update: Got the Brisk plugs, waiting on the new MAF to arrive before I throw everything together.

The car is running so lean now that I refuse to drive it til this is solved. Made a profile on Torque Pro, realized that my Fuel Trim Bank 1 was around 22% and Bank 2 hit 31%. And apparently it logged 35 misfires from start to when I shut it off..... So there's that.
 

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