Ok,,now another question and some help. 1992 Volvo DL-240, auto, 131,000 miles and runs well. In another thread, you have shown me how to by-pass the TEMP compensator board for elimination of the temp needle fluctuations



My spark plugs (all four) show light yellow. Never have seen "yellow" spark plugs as opposed to nice "light brown". What is causing this?



Timing is at 3 deg BTDC. Should be 10 deg +/- 2 (BTDC). No adjustment at the distributor. Firing at/near TDC is not good;



Is it possible the timing belt was installed wrong and the computer has compensated for the wrong firing point? Sensor is on the crank shaft and may be giving wrong "firing" info to computer??


Will view diagnostic codes (if any)



confused greatly and need some guidance pleasse.


thx..


abro
Brattleboro, vT

 

pop the timing belt cover off, and rotate the crank til the notch on the camshaft pulley lines up with the marks on the block, then check that the crankshaft pulley is also aligned. also check the aux shaft as that drives the side mount distributor.

and yeah, as you've deduced, ignition timing is entirely driven by the crank position sensor which has no adjustments... but it IS possible for the distributor to be grossly off... with the engine at TDC and the camshaft marker also at the mark, the rotor should be pointing directly at the #1 contact on the distributor cap.

 

OK....i goofed up...my timing is right ON for my 1992 VOLVO DL-240. I did not realize where the TDC mark was on the lower timing cover. Turns out "10" as stamped on the cover is actually 10 deg BTDC and my reading with my strobe light was a little to the left of the "10" mark. Therefore my timing is at 12 deg. VOLVO spec is 12 deg +/- 2 deg so I am a happy camper.


Thanks for all responded...should have realized 3 deg BTDC was impossible!!!!