84 244 dl. Has a rough idle. I replaced the flame trap and I noticed the plugs are good. The coil and dizzy cap is good as well. The temp gauge isn't working but I have a coolant temp sensor and I'm wondering how to get that in there. Lastly. Are there any things I can override or remove that I do t really need?

 

does an 84 have an IAC (idle air controller) ? is your throttle body gummed up? is the idle switch on the throttle body working ? (assuming an 84 has one)

 

Idk. New to volvos. I don't have a book for one yet

 

re your temp gauge, that uses a separate coolant sensor from the one used by the ECU/ICU (EFI control unit and ignition control unit). odds are good the temp gauge problem is wiring and not the actual sending unit.

the IAC is under the intake manifold and has rubber hoses to both sides of the throttle plate, and is used to regulate the idle speed by controlling how much air the engine is getting. its basically a solenoid actuated air valve, and the solenoid can get gummed up and sticky.

 

oh. there's really nothing in that engine's system thats not important to its operation. you have LH-II fuel injection, its very simple stuff. The distributor has a hall sensor which goes to the ICU (ignition control unit) and then to the ECU (EFI control unit), and this provides the timing pulses on how fast the engine is running. the ECU reads the output of the MAF (mass airflow meter, sometimes called AMM for air mass meter) to decide how much air is being sucked in so it knows how much fuel to inject. the engine coolant temp sensor tells both the ICU and ECU how hot the engine is so they can richen the mixture and retard the spark when its cold. the O2 sensor in the exhaust pipe tells the ECU if the engine is running too rich so it can lean it out (or if its too lean, so it can enrichen it) to maintain a perfect 'lambda' (air-fuel balance)