lately I've been having a slow idle and a general lack of power with my 1990 740
wagon. Its equiped with the Regina system.

Shouldn't ,at the very least, the air temp sensor give me a continuity signal?

I put a meter on it and I got nothing. Is it dead or am I just ignorant?

Any help would be appreciated.

I would think the impedance of the Air Temp Sensor would vary according to temperature.

If you have a multimeter use it to measure a fluctuation of resistance when applying a heat source to the sensor. If the resistance varies as the tempchanges, then the Sensor is good.

The output of the Air Temp Sensor is the inout to soemthing else, what that is, I do no not know sine I have not seen a schematic.

I hope this helps
--
'92 740 B230F Wagon::'92 B230F 240::'86 B230FT Wagon (RIP-Parts Car)

From the FAQ:

Regina Air Temperature Sensor. The Regina fuel injection system uses air pressure and temperature in the intake system to compute the air mass moving into the engine. The temperature sensor is located in the intake hose or pipe. The air mass passes through holes in the sensor and over a bulb which sends a temperature signal from the incoming air charge to the ECU. Information from this sensor is added to the pressure sensor information to calculate the air mass being sent to the cylinders. The sensor is an NTC (Negative Temperature Coefficient) thermister which means that resistance declines as the temperature increases. This sensor helps the ECU to determine spark timing and air/fuel ratio. You can check this resistance by connecting an ohmmeter between pins to read:

-20°C (4°F) 15K ohms
20°C (68°F) 2.5K ohms
100°C (212°F) 160 ohms
Use a heat gun to change temperature. Problems may occur in the sensor, the connector, or the wiring leads.
--
Ken
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'
Click here for the 700/900 FAQ
(or on the upper righthand of your screen, drop

Kenny,

Thanks, I read this already from the FAQs. Bruce sent me a pictiure of the MAP Sensor as it is mounted on the inside fenderwell (driver's side).

Mr Zorak says to inspect the 5th injector too as his was gummed up when he was having the same problem I am having. He used some Carb spray cleaner to ungum his #5 injector.

I was trying to locate a picture of the Air Temp Sensor as it is mounted in the AMM - according to Bruce, I believe him too. I was just hoping to see a sneak preview of the Air Temp Sensor before I go outside and get one of my nuts stuck to the fender (it's pretty cold out)..



--
'92 740 B230F Wagon::'92 B230F 240::'86 B230FT Wagon (RIP-Parts Car)

"I was trying to locate a picture of the Air Temp Sensor as it is mounted in the AMM"

Guess I wasn't clear. It's mounted where the AMM would be if you had one. But no AMM on Regina. The MAP input to ECU does the job quite well.
--
Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

That cold start injector can be seen directly across from the throttle body. As soon as you remove the throttle body, shine a flashlight directly across from it and you will see it on the other side. If you have trouble seeing it from the inside, look on the outside of the intake manifold for it. It has a light blue connector I believe.
--
93' 240 Classic Wagon 220K & 92' 740 Wagon Regina/Rex 90K

So is it yes or no?

I've read through the 700/900 maintenance section before. And I know where its located.

The answer was in my reply. It's 'yes', and the amount of resistance varies according to the temperature.
--
Ken
1990 Volvo 740 base sedan (B230F)
My Volvo 'Project'
Click here for the 700/900 FAQ
(or on the upper righthand of your screen, drop