Should my voltmeter be bouncing when checking my TPS setting. It reads 0.976 then drops to 0.897 then climbs to 1.09 then kind of settles at 0.976 but never holds. Car will not hold its idle at 1000 rpm? It starts at 1500 drops to about 1000 then kicks down to about 650 and wants to die. 87 5.0 aluminum heads, cam, roller rockers mac intake tube to trickflow top end.