New Engine - Sputtering On Acceleration

[cutlassman]

Hey guys, kind of sad to see this community fade over the years, but hopefully some of you have some thoughts on this. I bit the bullet and put a new engine in my ‘92 CS Convertible, 3.1L. Most of the top parts were transferred over to the new block. Old engine ran fine before, but blew out the LIM and hydrolocked. Runs and idles great now, but above say 30 mph I get sputtering/misfiring on acceleration under load. Any ideas? ICM and coil packs only have a few thousand miles on them. New plugs with engine install. Wires are almost new. Car sat for several months with 3/4 tank, Stabil added, but the fuel is about 10 months old. Swapped TPS. No difference. Vacuum looks good. Older fuel? Fuel filter? Bad injector(s)? MAP? I’m going to take it back to the mechanic if I can’t figure it out myself. 

 

 

[rich_e777]

Bad belt/tensioner, dried out vacuum lines, failing injectors, worn out O2 sensor, ethanol gas, corroded battery/starter/alternator cables and grounds are all things ive experienced in the different versions of the 3.1 running poorly or not at all. A compression and fuel pressure test might be a good idea here.