Bought a 96 2 door Blazer was told the motor's been swapped with a lower mileage one. Also told the fuel pump was replaced. Drove it home 2 miles and turned ino thedrive and it died. started right back up and i parked it. Next morning I go out to a dead battery. take it to autozone comes back as bad. so I replace that, have the codes read because its running rough and get 3 tps codes. So I changed the tps, air and fuel filters, and pcv valve.
What it does is stumble and miss,all the lights on the dash come on, (sometimes just the brake and abs lights) and it either dies or almost dies and then smooths out. it does it on anything more than 1/4 throttle acceleration, but if i floor it, it pulls throughand picks itselfback up. It does it hot or cold. it starts good sometimes develops the miss at idle and wants to die. Fuel pressure is within specs, no leaks, passed leakdown tests. once it threw p0300 p0140 and p1122. After researching my symptoms it seems as if theres a bunch of thing this could e. ive looked through the throttle body and its not washed. Ive sprayed a mist and checked for arcs on the wires, coil, and distributor. I dont hear any vacuum leaks, and like Isaid, fuel pressure checks out. But with solutions from replacing a leaky spider to a shorting neutral safety switch, Im lost. Love this truck but I cant afford to chase parts until i find the right solution. Any help or ideas are greatly appreciated

 

Because the engine has been swapped, I would check the grounds. One on the back of each head with 2 or 3 wires in each of the crimp on connections. There is another ground, maybe 2 if there not together, to the left of the timing cover by the crank sensor going into the block. It under the alternator bracket. That's where I would start.

 

UPDATE. I had a squeeling belt and I changed it when I did the air filter, well I go out to try and figure out what to start checking, and I start it and it squeels like crazy. I noticed the tensioner was weak and locking up. Changed the whole tensioner, and presto, it doesnt miss anymore except at 3/4 to WOT. Also now the tranny seems to slip after 2500 rpms. at least I can drive it now with a little more confidence. I'm just wondering if running on low voltage hurt any sensors that would cause my current problems. I checked the grounds and they seem fine.I'm going to do the Big 3 upgrade soon so that will help if I have any ground problems... Slowky but surely I'll bring this thing back to life!!