Hi,
I have a 98 Intrigue that was running a 98 GTP motor and everything was great except a slight stumble when going over 3k for a few seconds. Timing chain gear let go and I kissed a valve with the piston. I swapped out just the block with an L36 block. Now it hesitates, bucks and stumbles anytime boost kicks it, I can get it to run ok if I give it slight acceleration over 30mph. Engine has XP cam with 2 degrees of of crank advance, 130# springs and 1.65 rockers with stock heads. Gen 5 with N* maf, 42 lbs injectors, headers, 3" down pipe to catless 3" exhaust, 2" intercooler, Aremotive fuel pump. I run a 2.8, 3.0 and a 3.4 pulley and it still does but slightly goes away with the bigger pullies. All this worked and made 400 crank hp in June 18. Any ideas for where to look?
Thanks Steve