Spark Plug Question

[nicks1031]

Hey guys, so I installed a Procharger system on my 2006 Mustang GT and im running Autolite HT0s in the car. So my problem is that when i first start the car it comes on with no issues , starts right up. The idle seems pretty normal except for a slight bounce from the normal 750ish to about 500ish every so often. I do not know if the slight bounce in the idle is normal with the extra load from the procharger belt, or if it is being caused by something else. Now when i drive the car for a little while and the engine gets warmed up, when i go into neutral the engine rpm will drop to 500 and then the engine will die out. From this point when i start the car back up it will come on and then almost die again immediately. My first instinct is that maybe the spark plug gap is wrong leading to fouled plugs and engine stalling at idle. What do you guys think? Any help is appreciated thank you

 

[retfr8flyr]

Raise the idle in your tune to 800rpm when the engine is hot.

 

[nicks1031]

How can I do that?

 

[weather man]

How can I do that?

You need a tuner to modify the current tune in the car. If you do not have a good local shop, will need to remote tune it.

 

[nicks1031]

You need a tuner to modify the current tune in the car. If you do not have a good local shop, will need to remote tune it.

Got an appointment with PBH at the end of this month, closest date i could get unfortunately. I bought the kit used and it came with a sct 3 tuner with a dyno tune on it, from the exact same year car with exact same mods. So that tune is what is on the car right now because I figure its better than not having a tune at all. That's kinda why I thought maybe the plugs but it could very well be the tune as well.

 

[01yellerCobra]

Are the options unlocked in the tune? If they are you might be able to adjust the idle yourself for now.

 

[weather man]

Got an appointment with PBH at the end of this month, closest date i could get unfortunately. I bought the kit used and it came with a sct 3 tuner with a dyno tune on it, from the exact same year car with exact same mods. So that tune is what is on the car right now because I figure its better than not having a tune at all. That's kinda why I thought maybe the plugs but it could very well be the tune as well.

Every car is just a little bit different.

 

[nicks1031]

Are the options unlocked in the tune? If they are you might be able to adjust the idle yourself for now.

I honestly don't know

 

[nicks1031]

Every car is just a little bit different.

Yeah I know that much at least, thats why I had the dyno appointment set up anyway, just trying to see if I can work out this kink on my own for now but we'll see

 

[07 Boss]

Got an appointment with PBH at the end of this month, closest date i could get unfortunately. I bought the kit used and it came with a sct 3 tuner with a dyno tune on it, from the exact same year car with exact same mods. So that tune is what is on the car right now because I figure its better than not having a tune at all. That's kinda why I thought maybe the plugs but it could very well be the tune as well.

Was the strategy code the same for both cars? And every car is a little different when it comes to dyno tuning. What was the gap on the plugs?

 

[nicks1031]

Was the strategy code the same for both cars? And every car is a little different when it comes to dyno tuning. What was the gap on the plugs?

No idea about the strategy codes, plugs are HT0's right out of the box. Was told they're .035 but I think they are .045 and thats why I may suspect it is partly a spark plug issue

 

[07 Boss]

If your strategy codes are different that could be all it is. I'm surprised its even running to be honest.

I would pull one and check the gap. I gap my plugs at .030 with my twin screw.

 

[nicks1031]

If your strategy codes are different that could be all it is. I'm surprised its even running to be honest.

I would pull one and check the gap. I gap my plugs at .030 with my twin screw.

Yeah Im gonna check them , and my tuner recommended to gap them to .032

 

[01yellerCobra]

Always check the gap on plugs before installing them. Especially with FI. I'm going to agree with the rest and say it's a tune issue though.

 

[nicks1031]

Always check the gap on plugs before installing them. Especially with FI. I'm going to agree with the rest and say it's a tune issue though.

Yeah if that is it then I guess car is gonna be down for a bit

 

[01yellerCobra]

Yeah if that is it then I guess car is gonna be down for a bit

Better to wait a couple weeks then chance needing a new motor.

 

[gtman]

No idea about the strategy codes, plugs are HT0's right out of the box. Was told they're .035 but I think they are .045 and thats why I may suspect it is partly a spark plug issue

My nib ht0/frpp autolites were no where near the .032 the tuner wanted. The .045 is likely. I had to grind down a small feeler gauge thinner to fit into the gap.

Think the problem is likely in the tune you are running. Hope your issue gets figured out. May want go ask pbh for a start up tune for you to safely get there.

 

[retfr8flyr]

I really don't think the tune would have loaded if you have a different strategy code. Every combination is a little different, that's why mail order tunes always need to be checked with data logs. I think all you really need is to gap your plugs properly, for the FI and increase your idle. I doubt that function is unlocked in your tuner, most tuners will lock everything or just unlock the gear ratio and tire size. I wouldn't drive it anymore then you have to until you get your dyno tune.

 

[nicks1031]

I really don't think the tune would have loaded if you have a different strategy code. Every combination is a little different, that's why mail order tunes always need to be checked with data logs. I think all you really need is to gap your plugs properly, for the FI and increase your idle. I doubt that function is unlocked in your tuner, most tuners will lock everything or just unlock the gear ratio and tire size. I wouldn't drive it anymore then you have to until you get your dyno tune.

yeah Im staying off the road as much as possible, may give my tuner a call to see what he can do for me in the mean time. Thanks for all the feedback guys it really helps

 

[nicks1031]

Okay so I have an update on my situation, I switched plugs, I went with Brisk 3VR14S plugs gapped at .032 (Confirmed that plugs before were not gapped properly, they were bigger than .04) and I cleaned my MAF sensor. Car is no longer stalling at idle when warm which is nice, idle still slightly bouncing but not as much as before. Do you guys think the car is at least safe to slow poke around for now until I get on the dyno to dial it all in at the end of the month?