IA2 temps high, climb rapidly at idle, lower under boost....

[Quagmire]

Hey guys,

So IAT2 climb quickly at idle with 75F ambient goes to 120 very quickly, ~45s on a cold start. Highway cruise is right around 120-150F, as soon as i do a decel temps soot up into the 190s. I open throttle temps come down to 130-150. They slowly creep up on Decel. Looks like a big sine wave when i data logg from 120-200F. So I checked the intercooler pump is flowing at idle. I replaced the Tmap sesnor thinking oil somewhere. But same problem.

When i open throttle and boost temps rapidly come down. then shoot up again under decel. Inspected for lose wires on connect, nothing.

My last twos guesses are intercooler pump is intermittent, or there is a broken ground wire somewhere.... Any suggestions? I dont want to dump 120 bucks and not fixed the issue.

 

[Black02GT]

You sure your Boost Bypass Valve is working?

 

[bigmoose]

When you have the throttle fully closed on decel, there is little to no airflow over the IAT2 sensor, so it will read high from the conducted heat of the blower. Sounds normal to me

 

[Quagmire]

ya but when is in boost its like 150F min..... Spark tables are pulling.
If Boost bypass valve is not working properly, would not idlle at 20inH2O at idle? and when i tiped out it would still manitan boost? Currently when i tip out under boost at 4k it doesn't make boost. Ill check it though.

With a twin screw i should see around 140F max..... I can get the sensor to peg.

First thought it was a false reading.... Don't know if it is false anymore.

Just weird i rev it after a cold start on a 60F day and it jumps to 120F instantly.. I have lots of datalogs...

BTW heater went... FML so tearing into that, cant really test things until late next week.