I just acquired a 96 4 runner 3.4 engine. that will no start but it will crank over. the lady said the ecu was sent off and repaired because the scan tool would not communicate with ecu. I get it home and connect my scan tool and same thing the tool will power up but not communicate . The check engine light is on and I have checked all the fuses under dash and in the engine bay. Is there anything I need to check for this issue. I am wondering if this issue can be related to the no start even tho I have 45 psi fuel pressure and I have spark also

any help will be great

 

Check out the wiring harness. Make sure nothing is worn out, stripped, melted, pinched, etc. Look for secure grounding too. My guess is a bad electrical connection somewhere along the line. Hopefully others will chime in.

 

This thread has the info you need to test the OBDII connector....when mine wouldn't communicate it turned out to be a bad ground at pin 5. Post 7 is very useful...
https://www.yotatech.com/forums/f2/o...omputer-93580/