GN sputtering around 4,400 rpm

[BUICKGN3]

Since I’m off work this week I decided to tinker with my car some. I set the tv cable the way you guys told me and now I’m thinking my trans might not be as bad as I thought. It still doesn’t shift as crisp as I’d like but I don’t think it’s redlining like I thought. I set the scanmaster to rpms and it’s wanting to sputter bad around 4,400. The first thing that comes to mind is valve springs, I changed them probably 12 years ago, not a lot of miles,maybe 20-25,000 but a lot of passes and the car sat about 4 years while I was doing other stuff. Even sitting I know the springs are under pressure. I checked the prices on new Comp springs,around $40-50, but I can’t find my tool I bought from Kirbans when I changed them.
Who sells the tool now?
I’m gonna try a new module when I get a chance just to make sure but the springs need cha

 

[dank GN]

Okay acouple things come to mind when people have this issue. 1 the coil pack . Ohm it out it should be between 11-13k . 2 spark plugs. Gap them down around .20-.25 .3 valve springs . I like the comp 981 . They are stiffer but you will lose some seat pressure after the first couple heat cycles. Also measure the valve steam height and shim the springs the right way instead of just slapping them on and hoping for the best . I’ve seen people just slap them on and still have the same issue because the valve stems where higher then what they thought.

 

[Chuck Leeper]

Suggest you do some data logging w/ a PL, and look at some real time info, first.

 

[buddy]

Cotton performance sells the valve spring tool

 

[SCOOBY DOO]

Like Chuck says...grab Powerlogger and make a log. Sputtering could be fuel related. Guessing is never a good idea.

 

[rag231]

What is your fuel pressure doing during the sputter? Check spark plugs and O2 sensor. Just doesn't seem like valve springs to me. If you have some way to view your data the better.

 

[rag231]

Sorry my iPad didn't flip and allow me to see the other responses. All good advice.

 

[rag231]

Sorry my iPad didn't flip and allow me to see the other responses. All good advice.

 

[BUICKGN3]

I don’t have access to a data logger. The fuel system has a new Racetronix 255 pump, 60 lb injectors,new fpr,replaced rubber hoses at tank, Delco fuel filter and TT chip. The fp did rise 1:1 with boost but did seem to flutter when it maxed out. That could’ve been due to the sputter or the old mechanical gauge.
Can the coil pack be bad and the car run fine only until it gets to around 4,400 rpm?
New NGK UR5’s gapped at .32, should I close the gap down? I had boost turned down to around 15 when checking it.

 

[SCOOBY DOO]

Are you showing any KR on the Scanmaster?

 

[BUICKGN3]

I hit the recall and it only showed very little, I’m thinking about .8 I wrote it down but it’s in the car. I lift as soon as it 4,400 and started sputtering so I didn’t give it much time.

 

[SCOOBY DOO]

Any idea what the 02's were on recall?

 

[Pronto]

First off close down the gap and see what happens. Easy test.

 

[Jerryl]

Since you don't have PL, it can be assumed you run a 5.7 chip?
Car could be flooding at 15 psi.
What are the specs written on the chip?

 

[BUICKGN3]

I’ll have to look. I had him burn it for street use, pretty sure the boost I told him was 15-17 lbs, low timing 18-20 degrees. But I’ll look later today.

Since you don't have PL, it can be assumed you run a 5.7 chip?
Car could be flooding at 15 psi.
What are the specs written on the chip?

 

[Jerryl]

Without a scantool, you may need to throw a few $100 bills at the car just to get an idea what it might be. Lol

Update the location in your profile for some assistance.

 

[SCOOBY DOO]

Ohm the coil pack. 11-13 thousand ohms.

 

[BUICKGN3]

The coil pack ohmed out at 12, all of the Magnacore plug wires were in the 3’s.

 

[SCOOBY DOO]

Typically I've had ignition modules cut out at WOT in high gear. Driving normally they were fine...but a high gear load make's 'em fail. Coil pack might be failing under load. Got a known good one to try?

 

[Boostrules]

Did you ever figure out what was causing the sputtering? It helps the rest of the members when a solution is found & reported back.