Ing Timing part 2
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,045
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Ing Timing part 2
Checked the engine timing today. Using mt Auto X-ray, when cruising at 70 mph /3500 rpm/ 13% throttle angle I have 44.8 advance. I go wot and timing goes to 22 degrees advance. This sound backward to me. does it sound right to you?
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Originally Posted by toyvet1
Checked the engine timing today. Using mt Auto X-ray, when cruising at 70 mph /3500 rpm/ 13% throttle angle I have 44.8 advance. I go wot and timing goes to 22 degrees advance. This sound backward to me. does it sound right to you?
I can't attest to the actual 22 degrees being the best for your setup (seems low to me) but when you nail the throttle and go WOT, the system enters PE (Power Enrichment) mode which uses different timing and fuel tables and ignores 02 feed-back.
Mine system goes to the 36 degree range when I go WOT. At closed loop idle I'm showing 22 degrees.
I can only speculate that there may be some knock that is causing the ECM to retard the timing below what it should be for optimum power output.
How does the engine pull with 22 degrees?
Jake
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Another thought I just had: I'm not familiar with how Auto-XRay displays ignition timing, but it may only be showing the timing that the ECM is commanding and NOT including the initial timing.
If that's the case, you'd have to add the base/initial timing to the 22 degrees to give you the total timing.
Jake
If that's the case, you'd have to add the base/initial timing to the 22 degrees to give you the total timing.
Jake
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Originally Posted by toyvet1
Car pulls ok but is lacking low end torque but don't think timing is a issue for it.
Low ignition timing will DEFINITELY effect low end torque. As I said, mine (and most others from the posts I've read) have 22 degrees at idle and low to mid 30s at WOT.
Jake
Thread Starter
Burning Brakes
Joined: Jul 2000
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maybe lack of knowledge. Thats why I am getting more and more knowledge from this forum.
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
Racer
Joined: Sep 2002
Posts: 424
Likes: 0
From: Va, Beach VA
Originally Posted by toyvet1
maybe lack of knowledge. Thats why I am getting more and more knowledge from this forum.
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Originally Posted by toyvet1
maybe lack of knowledge. Thats why I am getting more and more knowledge from this forum.
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
6* at idle with wire unplugged. I don't know what it is with wire plugged its off the scale. But 22-24 at wot would be 28-30 if you add the six initial.
Maybe I'll bump up initial a little to see what happens..
With the EST wire CONNECTED, the timing mark WILL be off the scale because the ECM is adding a certain amount of timing to the base timing you set with the timing light.
Jake
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Team Owner
Joined: Dec 2000
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From: SE NY
Cruise-In II Veteran
If you have an '85-'89 L98 check the TPS base voltage (at 450rpm) and WOT voltage. If you bump the base setting from the stock .54Vdc to about .65Vdc you will get a little more fuel and spark advance for crisper throttle response.
Then try bumping base timing to 8-10deg BTDC. If your scanner shows any knock retard at WOT, back off a degree or two.
Then try bumping base timing to 8-10deg BTDC. If your scanner shows any knock retard at WOT, back off a degree or two.