Need some help diagnosing my idle issue. 1991 4runner 4x4 5speed with 22r converted to EFI, previous motor had a stroker that blew up. I then put in a zero mile newer 22re with zero miles and it hasn't been running right since. It has black smoke and very rough idle. I took it to a shop to see what they think and they got it idling decent by leaving a vacuum line unplugged. Truck has new injectors, starter, battery, have a tuned ECU ( could be the problem but swapped it out for another and still have the same issue. i will see if i can get pics or vid of the engine bay. Anyone have any ideas would be appreciated.
After searching think maybe might be my Mass air flow sensor. it has been taken apart and adjusted. Would like conformation from here instead of throwing parts at it first

 

I think with the mix of years and aftermarket\modified parts you have it is going to be hard for anyone to give you good advice. I think if you go back to stock 1991 22re ECU, with stock unmodified AFM, you can probably get some ideas from people here on where to start. Are you using stock Toyota in tank fuel pump with the OEM pressure regulator?

 

Fuel pump is stock and so is the fpr. Ive been trying to bring everything back to stock. im not mechanically inclined so learning everything as i go. I will work on getting a youtube vid of it running and the engine bay.
To add to this im not sure if the harness i have is even for a 91. Some of the plugs for my year are from an older harness. Im looking at getting an 02 sensor and the harness has been cut for an older style clip

 

Okay been messing with it a bit. Got an 02 sensor I need to put it. When I check the plugs they 02 sensor wire has been cut to a single wire plug. Also too when I induce a vacuum leak the motor starts to lean out and run slightly better with a high idle.

 

What exactly got tuned in your ECU and how?

 

idk, it has a jet performance sticker on it. I switched it out for another ECU anyway.

 

All right. I took apart the afm and adjusted it to go leaner. It seems to have fixed the issue drastically. It still hesitates under full throttle. Now my next issue is when i let off the throttle and coast the engine cuts off and dies.