My truck was getting some horrible detionation and I didn't feel like ramdomly replacing parts... and so I took it to a mechanic who seemed to know quite a bit about chevys...

Background:
Crate GMPP 350 Vortec - GM TBI Vortec manifold bored to 2"
68lb injectors, AFPR 17psi, custom Vortec454 EPROM from CFM Tech. (Programmed specifically for this crate motor and mods)

He did a good job fixing the little problems... correct thermostat, replaced the distributer (cause of detionation i'm sure)... but that is about where i draw the line. Next, he replaced my 454TB claiming it to be letting in 'too much air'. So, a brand new 350TB w/ 55lb injectors and he used my old custom 'blindy programmed' 350 chip. That replaced my 454TB/68lb and 'more accurately prgorammed' 454 chip?!? I've dropped over $500 in the 454 conversion, I don't want these parts going to waste!

He basically dogged down my motor so I wasn't fouling spark plugs every 4 months. Yet now that he has fixed my high fuel pressure problem, new distributer, and some minor details... I see no reason why the 454TB setup can't work. If it gets too much air, why not add more fuel? I can't stand getting 280-hp from a 300+hp engine!!

So, I'm debating with myself wheather or not to keep his configuration... or to go back to the 454. I hear of many people using the 454 with the Vortec... I don't understand how it was getting 'too much air'... more air is better, right? Granted the chip can't be perfectly tuned, it oaught to be close enough. They used the same programming from a simular Vortec/454 setup. Should I be happy with my dogged motor, does the 350 configuration he used sound right to you? It does run, but I want my power back! I'm happy he got it tuned the best he could, but I think the 454 setup would be better... I just don't understand his reasoning to not use the 454, besides its getting 'too much air'.

 

I didn't read it all (sorry) but the first things that come to mind are timing and fuel pressure (are you getting enough fuel?). Anyway I gotta go, I'll reply later

 

ok first go to his shop and pimp slap him then go and put the 454 setup back on. i run a holley 670 and i know that i am not geting too much air due to the facat i have vacume at 5000 rpm and up at wot so i would put it all back on and never take it there again. the guy sounds like a parts swaper not a performance machanic.

 

Put the 454 back on and get a new mechanic. From there dial in your tune.