TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

Timing Question

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Old Feb 7, 2001 | 03:04 PM
  #1  
chevyboy07 91's Avatar
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From: down by the river
Timing Question

When we time our cars and plug the harness back in>>>>doesn't the computer take over and put the timing back where it wants it???
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Old Feb 7, 2001 | 05:03 PM
  #2  
89RS355's Avatar
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From: Cincinnati,Ohio,Usa
I can't remember if you need to turn off the key, put the plug back in, then restart it. I think it should adjust it when you put it back in, even with the engine running. If your having a problem, are you puling the right plug? Sound's like a dumb question, but I seem to remember someone posting a correction to an incorrect procedure printed in a helms/chiltons manual.

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Old Feb 7, 2001 | 06:52 PM
  #3  
JoelOl75's Avatar
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From: PA
Car: 88 Firebird WS6
Engine: 350 TPI
Transmission: T56
Axle/Gears: 3.42
I don't think it works that way. I think the computer just controls the advance. Therefore advancing the distributer skews the whole curve upward to the point it knocks and the sensor pulls timing out. This is not good for performance though because it has to pull more timing to stop a knock .... ummm hard to explain.

OK

Say your base timing is 5 BTDC and your computer advances it to say 36 BTDC. You move your base upto 8 BTDC and the computer will adv it to 39 BTDC and runs better...OK

Then you move your base timing up to 9 BTDC and it pings at 40BTDC. The computer will have to pull out about 4 degrees to stop the ping (36BTDC) so you lose the advantage.

You can usually "feel" this in th 1-2 shift as a hesitation. Just retard it a bit till it goes away. 305's are knock limited motors so peak torque will be right before spark knock (in most cases on 305's, doesn't apply to 350's though...)

Hope this help you squeak out a little more power.
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Old Feb 7, 2001 | 11:24 PM
  #4  
chevyboy07 91's Avatar
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From: down by the river
Thanks guys, I'll work on getting the best advantage out of it.
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