Volvo 480 Club Europe

"how to adjsut idle on turbo" guide

step 1:
Check the throttle valve housing for dirt deposits
Clean the throttle valve housing as necessary.
-Do this by removing the throttle valve housing and cleaning it with a solvent. Make sure that no solvent enters the throttle valve switch!
-Note! a throttle valve housing which is contaminated by deposits indicates that the air filter is either blocked, incorrectly fitted or damaged.
-Note! Always use a new gasket when fitting the throttle valve housing.
also check and clean (if dirty) idle valve with a carb cleaner or something.

step 2:
Adjust the throttle valve to the basic setting
Slacken the lock nut (the chrome one on top of the TB(throtle body))
-Back off the adjusting screw until the throttle valve is fully closed.
-Tighten the adjusting screw until it contacts the link rod, then tighten it a further quarterturn.
-Hold the adjusting screw in the correct position and tighten the lock nut.
if you hear a click now, goto step 4 and adjust the base idle setting, else continue on step 3.

step 3:
Adjust the throttle valve switch
throtle valve switch is actualy in a throtle position sensor, the black box attached under the TB with 6 (or 5, 4?) pin conector.
Slacken the two bolts.
-Turn the throttle valve switch first clockwise (looking from bottom!!) and then slowly counterclockwise (!!) until a click is heard.
-Fasten the throttle valve switch in this position (the clicking noise is caused by a microswitch).
-Check: the click should be heard with the slightest angular displacement of the valve spindle. If necessary, adjust the throttle cable.

step 4:
Check the idle speed and adjust the basic setting
Move the idle speed regulating valve to the basic setting by earthing the cable* in the test point near the crankcase ventilation.
*B18F: brown/green; B18FT: brown/grey.
-Switch off the airconditioning and wait until the thermostat is fully open and the cooling fan has switched itself off.
-The idle speed should then be 11.7 r/s (700 r/min); adjust, if necessary, with the adjusting screw on the front of the TB. (brassy - gold colour)
-Remove the earth connection from the test point.
-The idle speed should then increase to 13.3 r/s (800 +-25 r/min).

if that doesn't help, check for air leaks, broken crankcase breathing valve, false temp sensor, false throtle postion sensor, MAF..







BTW:

The LH 2.2 system (turbo) adjusts the engine speed as follows:
Temperature___Engine Speed
+ 80C___800 r/min.
+20C___950 r/min.
-40C___1200 r/min.

The Fenix system adjusts the engine speed as follows, depending upon the type of engine:
Temperature___Engine Speed
Hot___730-950 r/min.
Cold___950-1250 r/min.

Move the idle speed regulating valve to the basic setting by earthing the cable* in the test point near the crankcase ventilation.
*B18F: brown/green; B18FT: brown/grey.

where is this cable that you speak of as my sons turbo has an idle thats going all over the place.

Two cylindrical connectors peeping out of the loom leading to the idle valve near the dipstick. Sometimes enlightened technicians used to permanently connect them, that's why caring people in order to prevent them doing so used to cut off the one connecting to ground. So you may only find one, connect it to ground and you'll have the desired effect. If none is present look for cut of wires in the loom. Whether the colors mentioned above are correct I don't know, but as one of the wires is connected to ground anyway it's no big deal to find the right one.

well would you believe it there were no wires lying around. The 480 was completely rebuilt by previous owner so he must have cut them off . went looking in the loom at random places couldnt find any wires answering to the description in the text. Can anyone put up a photo of the wires so I can try and trace back to the loom.

This comes as an afterthought, but if all the wires are missing either connector pin 4 of the EZ210K or 12 of the Jetronic LH2.2 (which are interconnected) may be grounded for this purpose.
The original cylindrical connectors do exactly the same. It is like sending the full open throttle signal to the ECU's.