i love my wagon. i work out of it and more. i take care of it and maintain her. i noticed a drop in gas mileage and then the check engine light came on. detected and 2.2.1 code and discovered it was a regina system. replaced o2 sensor with an oem regina sensor. same very rich symtoms. please help.

 

Check real good for vacuum leaks. Elbows and such.

 

thanks for the tip.
i looked for vacuum leaks and have not found any yet, however, i drove it a little yesterday and the "check engine" light came on. the same code of 2.2.1.
what now?

 

Check and or replace the engine coolant sensor. When it fails, it can provide a false (super cold) temp reading to the ecu causing rich conditions. Also, the 90 model had a TSB issued by Volvo offering a solution to the cold start injector running too long. Originally set up to run x seconds depending on temp, the solution is to wire the injector to the starter so it only activates during actual starting attempts.

 

after replacing the regina o2 sensor and checking for vacuum leaks the engine suddenly runs rich after full warm up.

what now?

 

i replaced the thermostat a few months ago. where is the temp sensor? i only see 4 injectors. where is the cold start injector?

 

The engine coolant sensor is under the intake manifold mounted to the head by cylinder 3. There is a gauge temp sender by #2...don't confuse them. After locating the cold start injector, temporarily disconnect it for a day or two and see if it makes a difference. It has an electrical connector similar to the main injectors.

 

would the temp sensor failure cause a 2.2.1 code? how would i really know that this is the problem?

 

Here is a very helpful link:

Engine Sensors

I would bookmark this site.

ECT when bad tell the ECU that the engine is colder then it really is and dump extra fuel in then needed, hence you are running rich. The ECT is way back there. There are two coolant temp sensors, one for the gauge on your dash, and one for the ECU. The ECT is a rectangle, while the one for the gauge has a rounded top. Hope that helps.

 

thanks for the help! i have located the senson on the engine. i have a regina system. do i need to get a regina temp sensor?

 

From what I have researched, the Bosch and the Regina ECTs are the same.