Timing

[Texvet]

1992, sclb, 5.7, 700R4, 118K
I replaced the intake gasket a while back. The truck started and ran great. After a week or so, it dawned on me that I didn't check the timing after the initial start up. I put the light on it and the mark was at the 12 o'clock position on the balancer, so I put it at 0 TDC. The truck is back to being it's gutless self. It idles solid - just dull!

Is there a "sweeter spot" to set the timing without doing harm?

 

[PlayingWithTBI]

I put the light on it and the mark was at the 12 o'clock position on the balancer, so I put it at 0 TDC.

Did you disconnect the EST (Black/Tan) wire when setting TDC?

 

[Texvet]

Did you disconnect the EST (Black/Tan) wire when setting TDC?

I did disconnect the EST wire.

 

[PlayingWithTBI]

OK, 12 O'clock seems a little high but I've added up to 8* before without getting KRs but, it's always best to do it in your calibration. Can you put a scanner on it and watch as you play with it?

 

[Texvet]

I don't have an OBDI scanner (I do have an OBDII code reader for my newer vehicles), and every time I've looked into one I get quickly overwhelmed. I am pretty handy, and have always done the majority of my own work. But - I am "Old School" handy. I can use a multi meter, timing light, set dwell (which I haven't done for decades) and use a vacuum gauge.

I am guessing the issue when monkeying with the timing is knock? I can live with the gutless performance. Like most people, I was looking for a magic, easy, cheap, no cost way to make a lo po truck run better then it was made too.

Be safe out there....

 

[Schurkey]

Might want to verify that the timing advance is working properly. All that is controlled by the ECM, via the ignition module.

After that, you NEED the scan tool to verify that additional base timing isn't causing detonation anywhere in the rev-range.

 

[Texvet]

Might want to verify that the timing advance is working properly. All that is controlled by the ECM, via the ignition module.

After that, you NEED the scan tool to verify that additional base timing isn't causing detonation anywhere in the rev-range.

What's involved to verify that the timing advance is working? Is it as easy as putting a timing light on it and reving it up looking for the timing mark to move?

 

[Schurkey]

What's involved to verify that the timing advance is working? Is it as easy as putting a timing light on it and reving it up looking for the timing mark to move?

That's where I'd start. It'd be worthwhile to map the advance vs. rpm and see what the curve looks like (no-load).

I'm not sure how you'd do this with the engine loaded. Dyno, I guess. Maybe pop the hose off the MAP sensor, but then the engine is gonna run crappy.

 

[kauila]

If your problem is the old balancer (damper) rubber having already slipped, the best bet might be to just reset the timing back to the 12 degrees you had originally.
I recall having the same problem and I did not bother disconnecting the EST wire. I think I just loosened the distributor and slowly rotated it one direction until I noticed the engine idle beginning to go down. I used a meter to check the idle. I marked that spot and then rotated the distributor the other way until the idle began to decrease. I marked that spot and set the distributor in the middle of both spots. It has worked so well for my old '88 Chevy, that I never bothered to buy a new balancer, even though my plan is to do so some day.

 

[Texvet]

If your problem is the old balancer (damper) rubber having already slipped, the best bet might be to just reset the timing back to the 12 degrees you had originally.
I recall having the same problem and I did not bother disconnecting the EST wire. I think I just loosened the distributor and slowly rotated it one direction until I noticed the engine idle beginning to go down. I used a meter to check the idle. I marked that spot and then rotated the distributor the other way until the idle began to decrease. I marked that spot and set the distributor in the middle of both spots. It has worked so well for my old '88 Chevy, that I never bothered to buy a new balancer, even though my plan is to do so some day.

Thanks....