Timing question

[SVFreddy]

So I just did a head gasket job on this 3.0lx I/O alpha one gen2, not too bad of a task. But upon setting timing per the service manual it states to jump the white wires at the distributer and disconnect the shift interrupt switch and connect them to each other, Did all that set timing to 1*atdc per the service bulletin for this particular motor after which the manual says that while the timing gun is still hooked up remove jumper wire and re-connect the shift intterupt switch that timing should now read around 12* btdc +/- 2* at idle, Which it did, Now they say that timing should advance to around 27* btdc while the engine is accelerated to around 2400-2800 rpms, Engine accelerated no problem but I did not see timing advance.... Am I missing something here? Am I suppose to be in foward gear when accelerating and checking for timing advance? What is the Idle engine rpm suppose to be when out of water and out of gear? manual says 650-700 idle rpm in fwd gear, Is that in water or dosen't it matter? Im on muffs and engine idle is around 1000rpms. Want everything done right since so much work has already been done.
Thanks

 

[littlebookworm]

Re: Timing question

What year engine do you have? Electronic engine or points? Computer controlled or not? More infomation is needed. You check timing in neutral. In most cases, engine should idle at about 800 in neutral, if I remember correctly. It may be at 1000 because choke isn't open yet. Running engine up to 2400 on muffs can cause problems - insufficient cooling from muffs. So, don't stay at that RPM for more than a few seconds. Have someone else work the throttle, in neutral, as you watch the timing marks. As the engine accelerates, do the timing marks move apart? Hy

 

[Don S]

Re: Timing question

Neutral is fine for checking advance, and assuming you have the EST ignition system since that is what those instructions are for.
Did you shut the engine off before you removed the jumper and reconnected the SI switch?

 

[SVFreddy]

Re: Timing question

its the 1997 3.0lx with EST. Had my buddy working the throttle in throttle only mode while I looked for advance, I did not shut the engine off before returning the wires to the SIS (Shift interrupt switch) and removing jumper wire. Timing did not advance when tach hit 2500rpms, stayed steady at 12*btdc +/-2*
What else should I be looking at?

 

[Don S]

Re: Timing question

I did not shut the engine off before returning the wires to the SIS (Shift interrupt switch) and removing jumper wire

You MUST do that step.

 

[SVFreddy]

Re: Timing question

You MUST do that step.

Will try again this afternoon and see if that does it, Thanks.

 

[SVFreddy]

Re: Timing question

So I attemped to check for the timing advance again and this time I did see it move, My question/concern is, Is it moving enough.
I've included a picture diagram so you guys can see where im at with this, Thanks for your input.

Just dosent seem like that would be considered 27*, Thoughts?

 

[Don S]

Re: Timing question

That's close, but I doubt your mark in the picture is accurately placed.
I extended your timing tab in this picture. You really need an advance timing light to check it accurately.

 

[Don S]

Re: Timing question

Was thinking about that drawing after I posted it, and have a way you could actually get an accurate reading without an advance timing light.

Use the picture below as a guide. Engine off, turn the crank pulley so the OEM timing mark is on the 12? BTDC mark.
Then make a new timing mark at 8? ATDC.
Now when you run the engine at 2500 rpm, your new mark will be 20? off, so just see which mark your timing is at. If it points to 4? BTDC, with your new mark, that means it's 24? BTDC.

 

[SVFreddy]

Re: Timing question

Thats about where it was reading (Granted my timing light is prob just a cheap sears brand from 1995) Thats why I wasnt sure if it was advancing enough.

 

[SVFreddy]

Re: Timing question

Was thinking about that drawing after I posted it, and have a way you could actually get an accurate reading without an advance timing light.

Use the picture below as a guide. Engine off, turn the crank pulley so the OEM timing mark is on the 12? BTDC mark.
Then make a new timing mark at 8? ATDC.
Now when you run the engine at 2500 rpm, your new mark will be 20? off, so just see which mark your timing is at. If it points to 4? BTDC, with your new mark, that means it's 24? BTDC.

View attachment 197010

Brilliant..... Thanks for the Idea.