ignition timing? how to do it right?

[hahaitzskippy]

alright guys, i have been searching the internet for answers but found nothing.

1985 318i, m10 engine, 30* BTDC @ 3000rpm

is what the specs are.

i look into the bell housing timing hole and i see the ball at TDC.

with a timing light, i see the ball move at idle (800-900, sometimes 1000)

however, when it is at 3000RPM, i do not see the ball on the flywheel at all!

am i missing something here?

i also checked the crank pulley/dampener. there are no marks on that either

lastly... does this make a difference? the engine is at TDC right now and look at the distributor...

[Chuck C]

Make sure you disconnect the vacuum line to the advance canister on the distributor before you try to set the timing. Your picture suggests it may still be hooked up, and that would be why the ball disappears at 3000 rpm.

[hahaitzskippy]

Make sure you disconnect the vacuum line to the advance canister on the distributor before you try to set the timing. Your picture suggests it may still be hooked up, and that would be why the ball disappears at 3000 rpm.

i am most positive that i already did that but i will def try again tomorrow

another symptom is the engine bogs down... hard to accel at WOT when the engine is warming up (still slightly cold)

[hahaitzskippy]

disconnected the advanced vaccuum line into the distributor... no change... it looks the same. no ball with timing gun...

i think i might have to take this into a shop..

[jeffnhiscars]

I take it its running ok since you are trying to time it so if your distributor is truly out 90 degrees, your spark wires are as well which could explain why your timing marks are not where you expect.

Re & re the distributor correctly then insure that the wires are where they are supposed to be.

[Hey_You]

:blowup:Who uses a timing gun to adjust their timing on a m10? Pffft!!!

[hahaitzskippy]

:blowup:Who uses a timing gun to adjust their timing on a m10? Pffft!!!

sarcasm isnt my strong suit :(

I take it its running ok since you are trying to time it so if your distributor is truly out 90 degrees, your spark wires are as well which could explain why your timing marks are not where you expect.

Re & re the distributor correctly then insure that the wires are where they are supposed to be.

ya the spark plug wires are set in the right order. i was curious about this before if it makes a different... i will try

[hahaitzskippy]

ok so i rotated the distributor 90* as suggested (didnt think it make a difference).

it worked. timing is spot on. idle is good again... power feels a bit low. kinda sluggish and bogged down...

fuel system to clean next

[jeffnhiscars]

ok so i rotated the distributor 90* as suggested (didnt think it make a difference).

it worked. timing is spot on. idle is good again... power feels a bit low. kinda sluggish and bogged down...

fuel system to clean next

[SoopaGhetto]

i timed by ear. advance until you hear some ping, then back off. go for a drive; at full load, you should listen for ping. If you have some, retard if not, advance. You may get to a point where advancing does nothing so retard. In other words, just play with it until you get the results you want. if not, go edis. Ive read a lot that trying to time to spec sometimes doesnt do well for a lot of people.

[Hey_You]

i timed by ear. advance until you hear some ping, then back off. go for a drive; at full load, you should listen for ping. If you have some, retard if not, advance. You may get to a point where advancing does nothing so retard. In other words, just play with it until you get the results you want. if not, go edis. Ive read a lot that trying to time to spec sometimes doesnt do well for a lot of people.

Amen

[jeffnhiscars]

I time by ear as well in part because the 8lb aluminum flywheel has no marks on it. I take a 10mm wrench and a $2 HF C clamp that I put on the inlet hose to the ICV then go for a ride to dial it in. The clamp lets me precisely adjust idle speed on the fly since every time you change the timing the idle changes (and since my various ICV's only work about 1/3 of the time anyway I often keep the c clamp in place 24\7). I set it to optimize my power band for my driving style and for the day of the week :-)

....and adjust your valves to .008. It makes a world of difference.

[Smelser]

I am guessing that there is a mark on the flywheel cause back in the early 80's there wasnt the technology they had today for timing lights.

my 1984 has a mark on the crank pully. I cant see anything on the flywheel.

can I use my spanky snapon light that advances to reference the 0 degree mark on the crank pully? by that I mean my light will advance the flash in increments so it shows the zero mark on my timing marks but the gun is advancing it to what I set. say 30 or more
?? if this is wrong let me know.

thanks!!

[E30SPDFRK]

I time by ear as well in part because the 8lb aluminum flywheel has no marks on it. I take a 10mm wrench and a $2 HF C clamp that I put on the inlet hose to the ICV then go for a ride to dial it in. The clamp lets me precisely adjust idle speed on the fly since every time you change the timing the idle changes (and since my various ICV's only work about 1/3 of the time anyway I often keep the c clamp in place 24\7). I set it to optimize my power band for my driving style and for the day of the week :-)

....and adjust your valves to .008. It makes a world of difference.

So when you adjust the timing should the idle fix itself if everything is working correctly? My car (84 318) idled perfectly at 900 or so but had rediculously retarded timing. I advanced it to where it felt strongest but my idle is at 1500 now. If I let it idle for a bit it'll go down to 1000 but as soon as I rev it up it's back to 1500.

The throttle is fully shut and I screwed the icv in to a half turn off closed.

[thebutterson]

If your timing is good but you can't get the idle correct you may have to try some of the ICV tricks people use. Search for the penny trick, the C-clamp trick, ICV delete, etc. Those are the easiest/cheapest fixes.