running 165 ECM and tunerpro
cold start 45F timing is at 8 degrees spark advance on my scanner.... runs really bad, i was able to mess with the following tables to increase startup spark advance to about 25 degrees but it will decay to 10-11 degrees by 112F where my closed loop kicks in at 115F. cold start RPM is dead solid at 1000rpms. I have 8* timing at the distributer, engine 383 HSR in sig with XFI 280 cam.

Startup spark advance vs coolant temp
spark correction-LV8 vs coolant temp
startup spark decay delay vs coolant
startup spark decay vs coolant

But i still cant seem to stop the spark decay from 25 to 10 degrees total advance on my AutoXray by about 112degrees F... do i change the Startup spark decay vs coolant table from stock setting of 0.18 to 0 or 0.09 to slow the decay rate? car starts better now but by like 80-90F the engine is at like 14degrees timing and starts to run worse. at 115F the cars 02 is warm enough and it kicks into closed loop and timing jumps to 24.8 and engine revs to 1500 and drops down to 1000rpms and runs great.

 

no one?

 

I would leave the startup SA alone. That is just a brief after-start SA to help prevent stalling.

Some of the SA decay is probably from the CTS SA compensation table. Which basically adds SA during cold operation and during normal CTS operation makes no change to the SA. With an overheating engine having SA reduced.

So as the engine warms up the SA is reduced.


The troublesome SA that I think you are having an issue with is the cold start SA logic. IIRC, it does exactly what you are seeing. No SA until the engine warms up some.

Try setting the CTS value at location $02B to 0 C and location $02C to 151 C.

RBob.


{edit: note that the above locations are for $6E. In $32B they are locations $02C and $02D. }

 

sry man ive only been tuning like 3 weeks lol. i have no idea what u are saying with the $02B and $02C. CTS is cold temp spark? so i should set all my tables back to stock?

im running the 165ECM which i know is a $32B mask but im using the AUJP bin and $6E mask... well actually the expanded6E mask.

 

AUJP is an $8D mask for the '7730 ECM. Used in the '90 - '92 f-body's.

The '7165 ECM used masks $32, $32B, and $6E in the f-body's, MY dependent.

CTS is Coolant Temperature Sensor, or the engine coolant temperature.

The locations I gave are the physical PROM locations for those calibration values. They are CTS thresholds for cold spark logic. If they are not in the XDF file you are using then can either add them or use the hex editor and modify the locations.

RBob.

 

sry i meant to say AUJL bin and expanded 6E mask. its the stock bin from an 89 Iroc 350tpi that i got from Orr89rocZ (due to cold start sensor delete which i needed bc of HSR swap)

so your telling me to max out the CTS which would accomplish what? Im not messing with the hex editor bc i dont understand how to change things and there locations in hex. I preferbly would just like to get the hang of it all by utilizing the tables. I wouldnt want u to have to explain how to modify the hex or how to since im sure u have better things to do.

But i opened up the hex editor and looked for the $02B and i couldnt find it... i saw a 00002B0 and when i clicked on it-it went to low speed limit for low speed gear unlock.

could it be anything else?

 

actually i might have found it. its called the coolant temp spark correction disable temp. it was set at 112.5F exactly when it would turn off and go into closed loop. i set it to 0F and it solved the problem. now my startup advance was like 40-42 degrees and then was at like 32-30 steady. im gona now set the tables startup spark tables back to there stock settings. thanks for the help RBob