a bit about the build
2015 - c7 z51 manual
procharger p1sc tuned by reputable shop to 585hp
Car has about 6000 miles since the blower was added.

Symptoms:
Hard acceleration through 1st, shift to second and reduce throttle to about 25% the car will hesitate, a on-off-on-off-on stutter. Inside the car it’s very jerky at it does through this and occurs mid rpm range in second gear.

however, if I stay full throttle in same situation the car pulls aggressively with no stutter.

On one occasion, as I tried to diagnosis and see what was going on did several pulls changing throttle application. During last pull check engine light came on and stayed on. Scanner showed misfire cylinder. I had done several repeated pulls and a tire smoke.

What has been done:
Cleared codes
checked all spark plugs and gaps
changed blower and engine oil
Called tuner but I’ve move out of state, they said to check spark plugs.

I’m learning and this is my first blower car. I’ve checked all that I know but lost if this is normal. Have started to think maybe it’s tied to the blow off valve? Like it’s getting to much air and not enough fuel? If I stay full throttle through the gears it pulls the whole time with no hesitation. But if I go hard acceleration through first gear and back out of the throttle in second gear to about 25% it does the on-off-on-off hesitation. A classic scenario is pulling up to red light. Light flips green, accerlate hard and back out of the throttle in second gear 40-60mph, car hesitation to the point that the nose of the car is lifting, falling, lifting, falling.

Main issue is I look like I can’t drive my car. And once I cleared the original cylinder misfire it never came in again.

Bump. Could really use input from anyone. When I checked the spark plugs, one of the wire plugs removed effortlessly. Would a bad connection or bad wire lead to these symptoms??

Is this a new issue, or has it been like this since the install?

Think it’s always done it since the install. It revs out clean on a full pull. Only happens when I get out of the throttle.

Traction control on ?

Traction control and stabilitrack off. No launch control either. Just a hard pull and back off in second gear.

I have had the same happen a few times. I blamed it on the older style 4” maf pipe I have on my A&A kit but maybe it’s something else.

If it has done it since the beginning, it could be in the tune. Was it tuned on the street? Dyno? Or both. Drivability is always harder for tuners to get spot on.

It was tuned via dyno and by reputable shop by the forum. I’ve called the tune shop but cross country so tough to swing by for diagnosis.

Whats weird is this issue seems to happen as the car builds up heat. I’m really starting to think maybe it’s a coil or wire based on the one instance of the misfire code coming in. But where that falls short in theory is on a hard pull it runs out no issue. It only happens when I back out of it in second gear

Thank you for your response and experience. Yes it did have a specific misfire cylinder. But I was to quick to clear the code to see if it came in again that I didn’t note which cylinder. Pretty sure it was number 7 though which also is the spark plug wire that seems to be very easy to pop off the spark plug. Will experiment over the week to see if that’s the cause

It’s not as simple as the blowoff valve fluttering between open and closed at part throttle is it?

i had the same setup as you with a very similar problem. If I started accelerating hard, changed gear and then had to let off the throttle, the car would surge. To me it felt like the bov was fluttering open and closed, causing the surges.

i fixed mine by upgrading to a 3.7” pulley and getting a retune from a reputable tuner. Not sure which fixed it, but one did.

I actually said either the tune or a smaller pulley fixed it. The additional PSI from the smaller pulley could have altered the rpm that the bov opened at, fixing the problem.

Also the off off the shelf procharger kit has a fairly quiet bov.