Sputtering and Hesitation WOT/Spark Plugs??

[K-Roll302]

This has been happening tuned and untuned recently. At first it would happen on certain tanks of gas where I'd mash the go pedal and it would hesitate and sputter to accelerate; and after refilling it'd go away. It's now been happening regardless of that so gas quality isn't my problem.

I'm pretty sure it's spark plugs and I had OEM plugs for at least 3000 miles without issue. I installed a set of NGK 6510s this afternoon hoping it'd go away but it didn't. Would spark plug gap too large be the cause of this? I was positive I gapped them to .028, but I can't pull them back out and check with a hot motor.

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[Datalux]

This has been happening tuned and untuned recently. At first it would happen on certain tanks of gas where I'd mash the go pedal and it would hesitate and sputter to accelerate; and after refilling it'd go away. It's now been happening regardless of that so gas quality isn't my problem.

I'm pretty sure it's spark plugs and I had OEM plugs for at least 3000 miles without issue. I installed a set of NGK 6510s this afternoon hoping it'd go away but it didn't. Would spark plug gap too large be the cause of this? I was positive I gapped them to .028, but I can't pull them back out and check with a hot motor.

If it was happening intermittently, and has progressed to a consistent issue, it suggests to me that something is failing. If you replaced the plugs and it still does it, is it possible it's the fuel pump?

 

[K-Roll302]

I've only got 18k miles. Has anyone had a fuel pump fail on them before??

 

[Fridge]

I've only got 18k miles. Has anyone had a fuel pump fail on them before??

If you already changed plugs next step is checking fuel delivery, either too much or too little. I know with Cobb you can monitor fuel injector load and fuel pump stuff through datalogs. Maybe your tuner can give you an idea before you start replacing parts.

 

[K-Roll302]

If you already changed plugs next step is checking fuel delivery, either too much or too little. I know with Cobb you can monitor fuel injector load and fuel pump stuff through datalogs. Maybe your tuner can give you an idea before you start replacing parts.

I'm gonna pull them one more time and just be 110% positive that I have them gapped right. Take care of the simplest things first and foremost before I go further.

I don't believe it's tune-related because it happened today with the tune on and off. Since spark plugs are the only part related to fuel mixture that I've changed, I've been directing my attention there. And my accessport hasn't got the ability to do any data logging.

 

[TorqueMan]

OBII codes?

 

[Regs]

Could be exhaust choke as well if you burned up the cat.

 

[Ecoboobs]

I'm gonna pull them one more time and just be 110% positive that I have them gapped right. Take care of the simplest things first and foremost before I go further.

I don't believe it's tune-related because it happened today with the tune on and off. Since spark plugs are the only part related to fuel mixture that I've changed, I've been directing my attention there. And my accessport hasn't got the ability to do any data logging.

Get the torque pro app then and a bluetooth OB2 adapter. Should be able to check fuel pressure/misfires etc and aid troubleshooting. Good investment and able to reset most ECU codes. Also, have you looked at doing a firmware update on your accessport to allow data logging features?

 

[TorqueMan]

Since spark plugs are the only part related to fuel mixture that I've changed, I've been directing my attention there. And my accessport hasn't got the ability to do any data logging.

You might also check the resistance on the plugs with an ohm meter. You should have an open circuit (no resistance) between the connector terminal and the center lead. If those check good test the wires as well.

 

[Blyman93]

I'm currently going through something similar. Went through 2 sets of ngk. Got Denso in right now gapped. 026-.028 and so far it's been running great. Only had one night where I did a few pulls and I got the misfire thing so it's odd that it comes and goes. But since then (3 days ago) it's been fine

 

[K-Roll302]

I installed a new set of Motorcraft plugs gapped at .028 earlier in the day and I haven't had any problems so far. AFR is where it should be, and I've been able to make WOT pulls without any issues...I'll post pictures of the previous plugs later on after getting some sleep.

 

[TorqueMan]

I installed a new set of Motorcraft plugs gapped at .028 earlier in the day and I haven't had any problems so far. AFR is where it should be, and I've been able to make WOT pulls without any issues...I'll post pictures of the previous plugs later on after getting some sleep.

If the new plugs end up solving your problem would you please consider measuring resistance on your old plugs? It's pretty easy to damage the conductor or crack the insulator on a plug; just dropping it can be enough.

 

[Juben]

It's pretty easy to damage the conductor or crack the insulator on a plug; just dropping it can be enough.

Yep, people don't really understand how fragile (to an extent) that they can be. They can be damaged with the damage not even readily visible. Measuring the resistance is a very good idea and would indicate any problems with the plug. :cheers:

 

[K-Roll302]

If the new plugs end up solving your problem would you please consider measuring resistance on your old plugs? It's pretty easy to damage the conductor or crack the insulator on a plug; just dropping it can be enough.

I'll certainly try! I'll figure out how to do it and report back. I went to a dyno event this afternoon and the car performed surprisingly well for it being a 90F and moderately humid day.

 

[TorqueMan]

I'll certainly try! I'll figure out how to do it and report back. I went to a dyno event this afternoon and the car performed surprisingly well for it being a 90F and moderately humid day.

Here's a good video:

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