Want to pass along a possible solution for anyone driving an 83 or 84 240 with LH2.0 and having hard COLD START issues. This has been a constant and long standing problem with my deceased 84 (10yrs) and with my new 84, (but only after recent work was done for unrelated issues). Hopefully others can take advantage of this "brief" summary.

The solution for my problem is detailed in a Volvo service bulletin, reposted below:


*************

FEBRUARY, 1984

THIS BULLETIN IS APPLICABLE TO THE U.S. AND CANADIAN MARKETS

If complaints of excessive cranking time are reported and all engine functions are normal, the condition may be caused by a lean mixture as a result of the control unit setting. This condition can be eliminated by installation of a 47k ohm resistor (available under P/N 1189980-4) between the starter motor circuit and engine coolant temperature sensor circuit.

INSTALLATION:

Route the female end of the "resistor wire" down between #3 and #4 intake manifold branches and connect to terminal #16 at the starter.

Utilizing a blunt instrument, carefully peel back the black harness covering of the fuel injection wires at the point illustrated.

(Ensure none of the harness wires are cut or damaged.)

Locate the solid blue wire (temperature sensor) and using a scotch lock connector, attach the resistor wire to the blue wire.

Repair the harness with electrical tape including the scotch lock to prevent:corrosion of the scotch lock connector and moisture entering the control unit harness.

The control unit senses the engine temperature by sending current through the temperature sensor. The resistance of the sensor is higher at colder engine temperatures. Therefore, the colder the engine the less current can flow through the sensor.

By connecting the "resistance wire" from the starter motor, additional current is supplied to the temperature sensor only while cranking. This additional current from the starter reduces the current flow from the control unit, indicating the engine is colder than it actually is. This permits a richer mixture while cranking and improves starting ability.

NOTE! Control unit P/N 1317029-5 for B23F M.Y. 1983 is superceded by control unit P/N 1346563-8 (original equipment for B23F 1984). Therefore, to avoid the possibility of startability complaints, when replacing control units on B23F 1983; the resistor wire P/N 1189980-4, should also be fitted.


***************


Below is my illustrated fix:





My personal thanks to Dasein and Art Benstein for their help in getting a grip on this.

I'm confident enough in this outcome, especially in light of comparisons with and without the "fix", to recommend this precedure to anyone having cold start issues with their 83/84, B23F, LH2.0 management. Over the course of the past 3 days, cranks now averge ONE SECOND regardless of engine ambient temp, compared to >>3-4 cranking cycles<< when cold which is how it should be.