Ignition Timing

[Tony D]

have to agree, someone moved the distributor, once it's set ALL timing changes are done via input into the computer, NOT changing the position of the distributor!

[meijerbrantm]

Right now, the timing light reads 18 at idle and the computer is commanding 25, right? To get them to match you could either advance the distributor 7 degrees or change the trigger angle 7 degrees, I'd advise moving the distributor and then locking it down. Once they match NEVER move the dizzy, ever, only change timing in the timing map.

 

Alright, well again yeah my distributor is way too mechanically advanced. So, according to what you say, I should retard the distributor. Then advance the trigger timing to match my map for spark (which is a map that someone else on this forum made for the l28et) then that way any adjustment I make there changes the actual timing then.

 

I appreciate the help.

[Tony D]

No, you have just taken what he said and turned it around 180 degrees!

 

ADVANCED means ADVANCED. You are currently RETARDED, and you need to ADVANCE your distributor just like he said. You don't change ANYTHING in the timing map.

 

The OPPOSITE of what you just said. One or the other, NOT BOTH!

 

Make the timing MATCH, then LOCK DOWN THE DISTRIBUTOR. From that point on, ONLY use the computer for timing changes.

 

I thought it was pretty clear from the posts.

[meijerbrantm]

like i said before though, is that my distributor has one bolt in it. You know the area that the distributor has for play (two ellipses on top and bottom)? My top one was cut so that it could mechanically advance more than it should. Now that being said, My distributor's bolt is going through the cut (meaning there is no way to fit a second bolt on the bottom cut unless i cut the outer edge of it.

 

So, said before, I'm 7 degrees off. If I retard the distributor 7 degrees and advance the trigger angle 14, shouldn't that do the trick so that my distributor is within specifications that it should be (on the engine block itself). that way i can put two bolts in it to lock it down.

Edited August 9, 2010 by meijerbrantm

[letitsnow]

That should do it

[bradyzq]

You'll want to check that the rotor is pointing to the correct post on the distributor cap once you've sync'ed the timing. It sounds like yours has been messed with enough that one should not assume it's pointing to the right post.

 

Basically, with the engine manually at about 25deg BTDC, the middle of the rotor should be pointing at post number 1 on the cap, or, if you'd rather set the engine at TDC (easier to do), the #1 post should line up near the back (trailing) portion of the rotor. If you ensure this is the case, you will reduce your chances of arcing to the wrong cylinder.

[S130Z]

If your timing is so off to where they had to "cut" the dizzy, I would guess the drive shaft for the dizzy is out of place. You should probably pull your oil pump and make sure your driving shaft is in the correct place.