NEED HELP TBI TO TPI CONVERSION TUNE ON 1227747

**cor242487** · 03-22-2014

Hey everyone so just a quick update. I have successfully got the truck to run on the 7730 ecm with a v6 stock chip. I also have been able to do the mod to the memcal to make it change cyl cycle to 8 apposed to 6. The repin from the 7747 to 7730 was a success and now i am moving onto setting up a tune for the setup and get some data logging happening. Hope i dont run into any issues. I am disabling the knock sensor as per the request of my buddy he is willing to take the risks since he does not want to remove the gear to gear setup. I will update later with progress. Thanks to everyone that passed along info you were all a life saver and i also learnt alot to you guys are the best!!

Corey

**TINBENDER59** · 03-25-2014

here is my build thread

http://forum.gmtruckcentral.com/showthread.php/1125-Convert-a-1988-TBI-to-TPI

**cor242487** · 03-26-2014

Hey guys so here is where im at with the tbi to tpi conversion. So i landed an ecm 7730 with a g1 adapter and a burnt chip for a 305 tpi but it was a tune set for a 700r4 not a manual.. also it was tuned for 22lb/hr injectors with a ported heads stainless steel valves and a bigger cam then what im running. So needless to say the truck runs not horrible on in but not right. So atleast i got the right memcal and scored the adapter with a spare chip for 175 bucks not a bad deal. So ive done some minor changes to the axxc 5.0 tpi bin file that runs the truck and started to try and get some data to find out some how i managed to put the diag wire in the wrong pin but no biggy a quick swap and i have data. Everything looked ok except the fact the iat was reading -40c.. i was like what well it turned out my buddy didnt wire that sensor up so i did that now i have iat readings. So when running the blm was running in the lean area of around 118 but what i couldnt understand and this where i stand is the spark advance at idle is 22 degrees but once i throttle even 1% it rockets to 40 degrees in that area which i havent messed with that just yet.

Any ideas as to what could be causing the huge spark advance? Im wondering if the spark advance tables i have with this bin are out? i looked at them they don't go into any outrageous numbers. And yes the timing is set 0 degrees TDC with a timing light. Now i have not hooked the 6.1 k ohm resistor in line with the knock sensor yet since where i live getting resistors seems to be a pain in the butt, but my buddy got a couple made up yesterday so im going to install them. That wouldn't have anything to do with it would it? Im a little baffled about the spark advance like all the other readings seem good except the blm at idle but under load its running 130 range which is right. So any input would be appreciated. Oh i should inform that i am getting an esc error code that doesnt actually trip the ses light but i am getting and ect error that unless i disable it in tuner pro trips the ses light. So ne thoughts would be great im going to install the resistors today and run it also i am going to read up on those codes specifically the ect code and see what the diag is for it. I hope its something simple i want to be done with this truck in a way and get working on my diesel again.

I will update if i get anywhere with this issue im facing and will keep my eye on the forum to see if any of you have an idea.. oh and one more thing im using the $8D-1227730 v1.1 adx file and i cant record any blm data any ideas there? Thanks in advance for any input i appreciate all of it

**dave w** · 03-27-2014

Originally Posted by cor242487

... oh and one more thing im using the $8D-1227730 v1.1 adx file and i cant record any blm data any ideas there? Thanks in advance for any input i appreciate all of it

I think you need to edit the history tables in the .adx file. Below are a few screen shots showing how to select the x-axis and y-axis values.

dave w