i just got done rubuilding my 96 ld9 and i drove it about 50 miles just fine. it ideled great, ran smooth and everything. it sat for like 9 months though and all of a sudden it started surging after it runs for a minute. my a/f meter read a little rich to stoich. it needs a good tune i know that. i need to put on my afpr and set the pressure but i am not sure what at for one. could it be it is doing this because of bad gas, clogged fuel filter of what? i lowered the compression to 8:5:1 for my turbo but i want to break in the motor before i put it on. what would cause this? thanks