Does it just missfire when cold? Id look into a leak down test to make sure valves are sealing properly and not just when heated where they expand and fill the gap. You can also do an ecu diagnostic test on your o2 sensors as they can cause cold start misfires.
@@goahoualee5205 can figure that by hooking a psi gauge up or looking at your pump and seeing its condition. Tank could be rusty from sitting. I try not to jump to conclusions and buy parts without diagnosing first. Learned that one the hard way. Don't think the pump would be suspect when cold as the pump really isn't going to be seeing a difference when the engine is cold/hot. Make sure you don't have and air leaks either. Likely alot of hoses are rotted from sitting so long.
