Sputter and pop above 19lb boost RIGHT AFTER valve spring change

[N2ORBT]

Just had a performance shop change out my stock springs for comp 980's. Did not re-use the stock spring cups like everyone is saying. Heat cycled the springs and did a WOT run the next day. Runs up well to around 19lbs then start getting some sputtering and popping. NO KNOCK during this sputtering. Cant visually see anything wrong with vacuum hoses. Car ran well up to 22lbs before the spring change. Not sure if this would be important but also had the intake pulled because a lifter came out of it's bore when they pulled the pushrod. They did not charge me for the intake gasket job and labor.:biggrin: Any ideas?

 

[TurboBuRick]

Run over all the vacuum lines. Check the cooler couplings and maf pipe connections. Maybe they left something loose.

RL

 

[DailyDrifter]

Rick has a good point. If anything the car should run better after having the valve springs installed, I would double check everything first.

 

[bison]

What installed height? What pressures? If they didn't use shims and check the heights you just wasted your $. Check your plugs and wires