EGR Valve 1994 Q45

[CJQ45]

My EGR valve is shot on a 94Q. Temp sensor is giving a constant reading 1.16V. I dont think the temp sensor is bad - although possible. I think one of the EGR vavles is not activating.

Heres the crazy part: When its cold outside (temp below 50F AMB reading) the MIL does NOT trigger. When its warm above 50F - the CEL comes on. Why would the CEL be depandant on outside temp? Is the vavle working when its cold and not when its warm? Makes no sense.

94 Q with 160k

HELPCJ

[Q45tech]

The purpose of EGR is to mix up to 10% by volume burned [oxygen poor] exhaust gases with cruise air flow [non idle non acceleration] to lower the combustion chamber temperature to reduce NOX emissions.

The amount of EGR [zero >10%] is a function of air temperature and coolant temperature and how much % EGR was preprogrammed to supply.........there may be a partial restriction in valve or tube allowing just enough in coolish weather and not enough in warmer conditions.

The ecu provides a variable pulse rate to solenoid to inject varaiable slugs [on/off/on]of EGR.Clean the passage way from plenum bottom thru and under temp sensor and into/out of EGR main valve.