Getting a Hesitation

**BarEaterB8** · 06-01-2016 05:59 AM

So recently, under moderate to hard acceleration I have been getting a hesitation/sputtering. It seems to happen throughout the powerband. The car starts just fine, and drives fine 90% of the time. There is no CEL's popping up but it seems to be getting worse. I am thinking maybe it's the plugs or coils but I am really not sure. I figure it has to be something with the ignition system. The car is fine at idle and under normal acceleration, it only happens when I really push down on the gas. Before I just start changing parts I thought I would ask here. I did a quick search and it seems like it is probably the plugs. I am Stage 2 Unitronic with the factory plugs. Thanks in advance.

**b6Hate4** · 06-01-2016 06:28 AM

Freshen up the plugs and coils just to start there, as they could probably use it anyways, and I bet they need to be gapped down. Another likely suspect would be the n75 boost solenoid valve if the problem continues.

**BarEaterB8** · 06-01-2016 06:45 AM

Cool, thanks. I just ordered some plugs and we will see. I went with the NGK BKR7EIX.

**blbroo** · 06-01-2016 07:18 AM

Originally Posted by BarEaterB8

Cool, thanks. I just ordered some plugs and we will see. I went with the NGK BKR7EIX.

Is your car running a tune?

**BarEaterB8** · 06-01-2016 07:33 AM

Originally Posted by blbroo

Is your car running a tune?

Yeah Unitronic Stage 2

**asfastas63** · 06-01-2016 07:42 AM

Originally Posted by b6Hate4

I bet they need to be gapped down.

This. Make sure to gap the new ones before they go in (and check the old ones when they come out). I just replaced mine and they were up at .035 and beyond. Everything runs much much smoother at .028 on a stg 2 tune.

**blbroo** · 06-01-2016 07:59 AM

We need to add a DIY to the stickie string on preparing for a tune. I'll write it up over the next couple of days with help from some other guys.

1. make sure your plugs are new and at least NGK 7 heat range and gapped at 0.028 or lower, this is even more important if you don't have an upgraded intercooler
2. if not on the new version coil packs, swap them in
3. make a run through all boost and vacuum hoses to tighten connections to avoid small boost leaks
4. maybe should be #1. How is your carbon build up? if bad, get it cleaned
5. To be continued

There should really be a checklist from each tuner for the car owner to go through before they have the file loaded, instead, many shops just allow you to pull your car in, pay them and have a tune loaded that demands much more consistency and precision from the car.

**BarEaterB8** · 06-01-2016 09:28 AM

Originally Posted by blbroo

We need to add a DIY to the stickie string on preparing for a tune. I'll write it up over the next couple of days with help from some other guys.

1. make sure your plugs are new and at least NGK 7 heat range and gapped at 0.028 or lower, this is even more important if you don't have an upgraded intercooler
2. if not on the new version coil packs, swap them in
3. make a run through all boost and vacuum hoses to tighten connections to avoid small boost leaks
4. maybe should be #1. How is your carbon build up? if bad, get it cleaned
5. To be continued

There should really be a checklist from each tuner for the car owner to go through before they have the file loaded, instead, many shops just allow you to pull your car in, pay them and have a tune loaded that demands much more consistency and precision from the car.

Thanks for the feedback:

I did the plugs and gaped them as you suggested. I haven't had a chance to drive the car yet but I will later today. If the hesitation is still there I will try doing the coils as well. Thanks for the help.

**BarEaterB8** · 06-02-2016 06:37 AM

So just by changing the plugs to a colder range and gaping them as advised, the situation seemed to clear itself up.

**blbroo** · 06-02-2016 07:25 AM

Originally Posted by BarEaterB8

So just by changing the plugs to a colder range and gaping them as advised, the situation seemed to clear itself up.

Nice!

Both the higher gap and the heat range lead to the plugs getting too hot, so hot that they explode the gas/air mixture before the plug even fires, causing the predet. It's really dangerous for your car to run like that because the explosion can happen while the piston is still on it's way up, possibly snapping a rod and shooting it through the side of your engine block. Less dramatic, it can blow the tip off of the plug, which can score your cylinder walls or F up your turbo blades.

Glad you got it fixed.

**ducati** · 06-02-2016 08:02 AM

So plug recommendation for a stock engine would be the NGK BKR7EIX?.I don't have any sort of issues just want whats best as a preventative measure.

**kt883** · 06-02-2016 09:21 AM

no stock is NGK PFR7S8EG

**sidkneeeeee** · 06-02-2016 11:23 AM

Originally Posted by blbroo

We need to add a DIY to the stickie string on preparing for a tune. I'll write it up over the next couple of days with help from some other guys.

1. make sure your plugs are new and at least NGK 7 heat range and gapped at 0.028 or lower, this is even more important if you don't have an upgraded intercooler
2. if not on the new version coil packs, swap them in
3. make a run through all boost and vacuum hoses to tighten connections to avoid small boost leaks
4. maybe should be #1. How is your carbon build up? if bad, get it cleaned
5. To be continued

There should really be a checklist from each tuner for the car owner to go through before they have the file loaded, instead, many shops just allow you to pull your car in, pay them and have a tune loaded that demands much more consistency and precision from the car.

what is the benefits of carbon cleaning?

**BarEaterB8** · 06-02-2016 12:46 PM

Originally Posted by blbroo

Nice!

Both the higher gap and the heat range lead to the plugs getting too hot, so hot that they explode the gas/air mixture before the plug even fires, causing the predet. It's really dangerous for your car to run like that because the explosion can happen while the piston is still on it's way up, possibly snapping a rod and shooting it through the side of your engine block. Less dramatic, it can blow the tip off of the plug, which can score your cylinder walls or F up your turbo blades.

Glad you got it fixed.

Thanks for the great advice!

**b6Hate4** · 06-02-2016 02:44 PM

Originally Posted by sidkneeeeee

what is the benefits of carbon cleaning?

Come on man...use the damn search button.

**ducati** · 06-02-2016 04:08 PM

Originally Posted by kt883

no stock is NGK PFR7S8EG

Yes I know but would a colder plug like the NGK BKR7EIX be smoother?.I'm getting very light roughness during idle.

**dbv2** · 06-02-2016 05:35 PM

NGK PFR7S8EG recommended gap size?

I also get a hesitation, I just did plugs and R8 coils, no tune. I'm not sure if its a boost leak or its the ignition system. I did not check the gap size prior to install.

**blbroo** · 06-02-2016 06:59 PM

Recommended is 0.032 stock and 0.026 or 0.028 tuned

**BarEaterB8** · 06-03-2016 06:09 AM

I am amazed at how much smoother the car is just by changing the plugs. Acceleration is much quicker and I am at 70 like it is nobody's business. I am passing people who I think are going slow and I look down and I am at 90. I was always a bit skeptical after I got my tune that I did not notice that much of a difference but now, two years later I notice it. I can't believe I didn't do this sooner.

**blbroo** · 06-03-2016 07:41 AM

Originally Posted by BarEaterB8

I am amazed at how much smoother the car is just by changing the plugs. Acceleration is much quicker and I am at 70 like it is nobody's business. I am passing people who I think are going slow and I look down and I am at 90. I was always a bit skeptical after I got my tune that I did not notice that much of a difference but now, two years later I notice it. I can't believe I didn't do this sooner.

Awesome, it's like a $30 tune upgrade.

**A4x** · 06-03-2016 08:07 AM

Originally Posted by BarEaterB8

I am amazed at how much smoother the car is just by changing the plugs. Acceleration is much quicker and I am at 70 like it is nobody's business. I am passing people who I think are going slow and I look down and I am at 90. I was always a bit skeptical after I got my tune that I did not notice that much of a difference but now, two years later I notice it. I can't believe I didn't do this sooner.

When was the last time you changed your plugs?

What do you guys reccomend to change at? I think the maintenance schedule calls for every 55000km (34000mi).

I'm on the stock tune and it has been at least 35000km (22000mi) since my plugs have changed. I'm not even sure cause I bought the car used (CPO). Could have been a touch longer. I think it's time I order some.

**asfastas63** · 06-03-2016 09:37 AM

Originally Posted by A4x

When was the last time you changed your plugs?

What do you guys reccomend to change at? I think the maintenance schedule calls for every 55000km (34000mi).

I'm on the stock tune and it has been at least 35000km (22000mi) since my plugs have changed. I'm not even sure cause I bought the car used (CPO). Could have been a touch longer. I think it's time I order some.

Just as a data point, I did mine for the 55k service and at 98k I got my first full load misfire. New gapped plugs and drives much better. I'll probably go every 40k from now on.

**BarEaterB8** · 06-03-2016 11:23 AM

Originally Posted by A4x

When was the last time you changed your plugs?

What do you guys reccomend to change at? I think the maintenance schedule calls for every 55000km (34000mi).

I'm on the stock tune and it has been at least 35000km (22000mi) since my plugs have changed. I'm not even sure cause I bought the car used (CPO). Could have been a touch longer. I think it's time I order some.

For the $30-40, and 15 minutes it takes. It doesn't hurt to do it.