The following relates to my July 2 post and is offered in hope of getting to the root of my problem = poor running when ignition advance is increased on closure of the radiator coolant temp sensor (which also activates the electric cooling fan). My Volvo shop manuals are confusing (at least to me). There are several references to an " ignition advance relay " triggered by the radiator coolant temp sensor. In one case it suggests that this applies to the B230T engine but in another manual it mentions only the B28 engine. Since I cannot find this relay in the location shown on the diagram (next to the main fuse/relay assembly), I'm now assuming that I don't have one (unless hidden elsewhere). So HELP :
1 - Does a 1986 740 Turbo have an "ignition advance relay" ?
2 - If it does, where is it?
3 - If it does not, by what means is the ignition advanced when the coolant sensor switch closes? ( I know that this happens via a timing light)
4 - Does anyone know how to disable the ignition advance but still allow the electric fan to operate ? ( I believe this will get me out of trouble without getting to the root of my problem)

If anyone has experienced a similar problem when the fan and ignition advance kicks in (rough idle and 2-4 second lag accelerating from stop), I would appreciate hearing from you.
THANKS