Hakuna matata pools

1995 k1500 5.7l 350 tbi auto 4l60e. Starting a new thread because I have a different scenario then all posts I've read before (days and days worth). Ok, so new motor from jegs, basic stock replacement. Put edelbrock performer tbi intake on it. Has full lengh headers 2 inch pipe all the way back, stock (new) mufflers, no y pipe, true dual. Only using 1 02 sensor, throwing no codes. I have replaced the following parts, in which some tested perfect in everyway there is to check but replaced anyways, tps x2, iac and pigtail, temp sen (both, one on intake 2x), map sensor, egr solenoid, all vac lines, throttle cable, alternator, water pump, plugs (e3), wires (8mm), distributor, rebuild tbi 3x (all insides replaced every time, including gaskets and regulator), injectors, fuel pump 2x, fuel tank, fuel sending unit, fuel filter 3x, damper, grounded whole truck (.7 ohms anywhere on the truck, yes tested at computer and tailgate), battery, air filter, ac compressor (but not hooked up and never turn on), have tested with carb cleaner for intake or vac leaks, neutral safey switch, had to rewire several items from ecm due to bad connections, tested almost every wire that goes to trany or engine for proper voltage or ohms. I' sure there are several things I may have forgotten. But the only things that have not been replaced are the her (tests out good), the torque converter, and the ecm/pcm. I have set timing to 0 with brown wire disconnected. When cold it's very sluggish, when up to temp it' a little bit better but still bogs on accel. At about 2500 rpm it comes to life and takes off. The transmission was rebuilt 4 years ago (drove for 6 months with it then parked for 3 years due to blown motor), ****ty job, shifts hard and Speedo stopped working properly after it was done, reads to fast, bought a vssb with dip switches for it so i could get it to read right, changed vss no change (no idea if this could cause acceleration issues). Any ideas?

JDub$ter

I'm having the same issues and have checked almost everything that you have mentioned. It sure is frustrating but I guess part of owning one. I'm about to take it to the dealer and pray that they don't take me for a ride. Have you checked to make sure the ECM behind glove box has the right prom? A common issue seems to be part houses selling the wrong ECM to customers or the customer doesn't use the original factory prom with original numbers. (Ex: 161 or 162 depending on the model). The dealer uses the last 8 numbers in the Vin # to determine which ECM module goes with the original prom but if the motor was ever swapped in my opinion it could cause huge issues but I'm no expert in the area. Anything failing can cause the whole system to go nuts and show fault codes everywhere.

Hakuna matata pools

yes it' the right ecm. I have 2 more parts coming in. I' replacing the spring for the fuel regulator, I have never replaced this one and makes me think that because it can only get 9psi fuel pressure it is worn out, and the oil pressure sending unit again.

JDub$ter

Keep us posted, I'm still troubleshooting my issues too.

Hakuna matata pools

I replaced the spring for the fuel pressure regulator wth a yellow 14psi spring sold on Amazon, fixed the problem. It still feels a tad sluggsh so I plan on upgrading the fuel pump to a 1996 vortec fuel pump so I can run the 14psi and not 12psi, the stock fuel pump for the 1995 has max pressure of 12psi.