I have a 78 chevy pickup that I have done an 89 tpi conversion on. 355 10.5:1 comp with factory tpi iron heads, lunati voodoo cam, modified 24 lb injectors from ls1 (28lb at 60 psi), long tubes, factory intake and tb, no vss, no tcc, 700r4 trans w/ 2200 stall, running moates chip adapter with tp v5 running 165 ecm with $6e mask. innovate lc-1 wideband with simulated o2 going to computer and wideband gauge installed in dash

I have been tuning on this truck off and on for a year trying to dial it in and have had alot of success, but still have a few hiccups to iron out. My question is, I have a rich decel issue that is plaguing me. My blms from tables 1-3 are spot on 126-130 during cruise and light throttle but during decel from cruise my blms drop to 108 and wb indicates 12-13:1 afr causing my next acceleration to begin lean 16.5-17:1 afr because of the stored low blms. I have tried messing with the dfco and decel enleanment settings but still seem to have the rich decel. Is my lack of a vss causing this problem or do I need to keep working with the decel enleanment and dfco settings to correct the problem. Its a cruiser and doesnt really get driven aggressively enough for the dfco to kick in much (usually no higher rpm decels) except maybe slowing from highway speed but haven't seen much reaction from changes in decel enleanment settings

 

same problem here, 7747 tbi zz383.

 

I would focus on the DFCO thing first and then later with the lean acceleration.

I would then focus on acceleration enrichment after you fix the DFCO thing. I think that you have to be over a certain MPH for DFCO to kick in so your VSS may be the problem. Although I'm not 100% sure.

If you are okay with no DFCO then maybe try to add some acceleration enrichment. Try lowering TPS percentage threshold.