Edelbrock Multi port conversion tuning

[Mattlwright]

New forum member here in need of some technical help. I have an 87 1500 with a Edelbrock multi port for TBI conversion. I am running a dynamicEFI ecu and heated O2 headers and Flowmaster exhaust. I am having a tuning problem that I think may be related to timing. The bin that the truck is running on which is basically the 87 TBI bin with the fuel rate cut down has initial timing at 20 degrees and max advance at roughly 42 degrees. I have a stumble just off of idle that feels like the timing is slow. In short do we have any EFI tuning experts on the forum or can anyone refer me to one??

 

[89Suburban]

Jim?

 

[Jims86]

20 is waaaaayyyy too high. Quite a few TBI timing tables from GM OEM are 4 degrees initial, with some of the heavier duty engines being zero'ed. Use ASDU as a guide, timing should not have been messed with just for multiport. Also, get ahold of Dave W or EagleMark on Gearhead-efi.com and see what they say as well.
Edit: thats 4 degrees in the SA table at idle, with base distributor set at 0 degrees.