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Discussion Starter · #1 ·
'92 Rodeo GM 3.1 V6 TBI. Lunges at around 1500RPM.

I was checking timing today. After I reconnected the EST bypass wire, I was seeing how it advanced the timing in relation to RPMs. From 700 to about 1500 it stayed dead on 10 degrees BTDC. At about 1500 it suddenly jumped to 13 degrees then slowly advanced as I accelerated the engine further. If I backed of the throttle it jumped back to 10. There was no smooth advance in the timing from 10 degrees to 13.

Could this be causing the lurching I experience when driving?

Am I right in thinking that the timing should advance smoothly with acceleration?

If this ain't right then what's wrong?
 

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With the ESC wire connected you should have WAY more that 10* timing at idle. It should be off the scale. Are you sure you set the timing right?
 

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Discussion Starter · #3 ·
With the ESC wire connected you should have WAY more that 10* timing at idle. It should be off the scale. Are you sure you set the timing right?
Well I am pretty sure I did. I disconnected the EST wire. Idled at 700-800, set timing to 10*, reconnected the EST. Did I miss something?
 

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Discussion Starter · #5 ·
shooter
you should have an at idle timing of 10* BTDC "below" 1,000
rodeo joe
Idled at 700-800, set timing to 10*
Again I ask, Could this be causing the lurching I experience when driving?

Am I right in thinking that the timing should advance smoothly with acceleration?

If this ain't right then what's wrong?
 

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The timing should advance smoothly. Sounds like the computer or data from one of the sensors is causing the sporadic timing issue. Read the part you wrote about a constant 10* from 700-1500 sounds wrong. Instead of running the rpm up several hundred until the timing advances, have you tried turning the dizzy at the constant 700 rpm to see if it advances smoothly or does the same as it did by increasing rpm? Regardless, sounds like it's time to pull codes.
 

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Yes disconnect the ESC wire and time the motor. Then tighten the distributor and confirm timing. The shut it off! Key step. Then after shutting it off with the key in the actual off/lock position. Reconnect the wire and then start it up. You should now see the timing off the scale at idle with the ESC wire connected. If not then you do have a problem. Most likely cause would be the module in the distributor or possibly the knock sensor and its module. If the ECM is stock there wont be any issues with it.
 
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