Spudder and pop

[fatkid1983]

need help 1987 Grand National 60,000 miles, if I get on the accelerator hard and hold it it will build boost great but eventually it will spudder and kind of pop it only does it under full acceleration. Half pedal its fine bit if I try and go full pedal it'll pull hard but then start to spudder again. I noticed tonight that when it "pops" or spudders it puffs a lil blue smoke out the tail pipes at the same time? What shoul I start with? Already replaced fuel fliter and done injector cleaner in it. Plug wires look new but I should probably just do a full tune up. Just wanted opinions. Thanks in advance

 

[josh young]

Does it do it when the car is cold? Or is it once it's up to temperature? Do you have a scan tool? Mine had a similar problem that turned out to be the cam sensor cap. It would only break up under full throttle, it was heat related though. Could be module or coil pack also, as well as about 50 other things. Maybe some more will chime in. Good luck!

 

[fatkid1983]

Thank you for the help, it doesn't matter cold or hot it does it