keithblazer

truck wont start unless you hold gas pedal open slightly. after that it idles and runs fine. engine was replaced with a used engine 68k miles. is there a iac reset procedure thank you

keithchevy

could this be a dirty throttle body or clogged iac passage?

Chris Stewart

It makes me wonder about the TPS.

keithchevy

tps voltage should be what at idle position?

old_master

Not recommended to use voltage as a test. On a scan tool, TPS is measured in percentage open, should be zero % at idle.

keithchevy

using mt 2500 scanner tps % is 0 at idle and reading .63 volts

old_master

Check fuel pressure, key on engine off, fuel pump running. Or you can install a fused jumper wire from the battery to the empty, recessed terminal right in front of the fuel pump relay in the underhood fuse panel. Must be 60 to 66psi and remain above 55psi for several minutes after the pump shuts off.