Timing question ??

[EA2BA]

In the below pic (option 1 or option 2)



Option 1 : If the timing mark goes more towards or past IGN is that going further advanced.

Option 2 : If the timing mark goes more towards or past TDC is that going further advanced.

[ratter]

The balancer goes clockwise and comes to ign before TDC, the more left of ign the more advanced it is.

[neb]

option 1 .... i think

[ratter]

Originally Posted by ratter

The balancer goes clockwise and comes to ign before TDC, the more left of ign the more advanced it is.

yes option 1 is correct, that's what I meant

[EA2BA]

OK then now for another question:

in 1st gear full WOT car revs to 4,800 feels like no legs are left, revs but not alot of action then changes gears, used to get out to 5,200 and a good clean change.

Does this mean timing too far advanced, or too retarded.

[svo347]

advanced.

[svo347]

You advance the timing to get peak revs lower in the revrange, to retard the timing brings it on later obviously, allowing the power to come in later

[EA2BA]

thanks guys, will back the timing off and see if I can hit the peak revs like i used to, then i will be happy.

[needturbo6]

why are you going for peak power, 3.9L have none in stock form especially at 5200rpm? is your motor much modified?

[ratter]

The timing curve in the computer is set at the factory and probably not ideal for max power, but retarding it to get more power will not work if it is set correctly, if you retard it too far it will be gutless and slow to rev at all points of the rev range and if retarded enough will run hot, and if you advance it too far it will rev quicker, probably get slightly better economy but may start to ping, if it pings it will drop power anyway but you will stand the chance of doing engine damage.

What fuel are you running, if running 98 octane you should be able to advance it a little more than the recommended figure without it pinging


Have you altered the timing to start this problem, because the timing should not change unless the distributor is moved.

You may have another problem that is causing the loss of revs - dirty air filter etc

[EA2BA]

ratter, yes my air filter needs a clean, and I am running stnd unleaded (used to rev 5,200rpm on that too) but when I replaced the timing case and a broken guide the chain moved, so I had to reset all the timing, and hence it is out i believe, I have set it 'about' right, but think it is a little to advanced at the moment, I didnt get a chance last night, so tonight I will be adjusting and some test'n'tune to see how it goes.

[EA2BA]

OK, backed the timing back a little bit, engine feels heaps better and now revs out then changes gear and keeps on going, could probably be backed off just a smidge more, but for now I am happy

[ratter]

Glad you got it sorted