Hello all,
Fresh rebuilt top and bottom (2001) 496HO's PCM 555, Port motor rpm's are off compared to Stbd and I'm missing 10 mph, verified new plugs, wires, checked coils are in the right order. Compression is good. Port motor IAC shows 99% when idling and you have to play with the throttle to get her to rev properly. At which point the IAC % lowers, but then back at idle its right to 99% again. I have replaced the MAP sensor and TPS. I swapped the IAC from the known good motor, no change. I swapped ECU's, no change. I have been chasing this gremlin for over a year, even before the rebuild. I'm at a loss. I don't know that the IAC is the issue but what would tell the IAC it needs to stay at 99% all the time. Could I have a coil issue? I am going to check fuel PSI today but it seems to be ok.
If I don't ease in to the throttle on that motor I can hear a pop on the throttle body side of things. Diacomm laptop scan shows no stored fault codes, would a running data log show anything? Missing 1000 RPM on the top end of this motor. Help!!
Thank you!
Fresh rebuilt top and bottom (2001) 496HO's PCM 555, Port motor rpm's are off compared to Stbd and I'm missing 10 mph, verified new plugs, wires, checked coils are in the right order. Compression is good. Port motor IAC shows 99% when idling and you have to play with the throttle to get her to rev properly. At which point the IAC % lowers, but then back at idle its right to 99% again. I have replaced the MAP sensor and TPS. I swapped the IAC from the known good motor, no change. I swapped ECU's, no change. I have been chasing this gremlin for over a year, even before the rebuild. I'm at a loss. I don't know that the IAC is the issue but what would tell the IAC it needs to stay at 99% all the time. Could I have a coil issue? I am going to check fuel PSI today but it seems to be ok.
If I don't ease in to the throttle on that motor I can hear a pop on the throttle body side of things. Diacomm laptop scan shows no stored fault codes, would a running data log show anything? Missing 1000 RPM on the top end of this motor. Help!!
Thank you!
