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Local Tuner Won't Touch It

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  • Local Tuner Won't Touch It

    Called a local tuner (only one that comes up in my area) and he doesn't have the software, doesn't know the system and doesn't want to know the system. Said I should have gone with a mainstream system like Holly or FiTech instead of something "off-the-wall." So I am hoping I can get some help here.

    I purchased the new engine of a GM Goodwrench re-seller. It was a "new" remanufactured 454 that you would order from a dealer. The guy who bought it, did so to replace an RV motor. When it came in he determined it would not fit and could not return it. So I got a deal...

    I do not know much about the engine outside of that and what I can decipher from the castings

    Block Casting 10114182 Big Block V8 1991+ 454, 4 bolt, Generation V
    Block Suffix Code PCT 1991 - 454 - 230hp - MT/TBI - TR
    Head Casting 10101140 1991+ oval port, closed chamber, Gen V 366 Tall Deck, 427 Tall Deck

    It is in my 1995 Chevy K2500 that I built as a tow vehicle. I had a 4l80e rebuilt and put a CompuShift TCU on it. It runs nice enough around town but I want to get everything out of it from the correct tune. Realized I am in over my head and looking for help.

    Thank you,


  • #2
    I believe that those systems require manual adjustments to the fuel maps table to get the correct AFR desired for specific conditions. The PF4 is different. The ECU learns your setup by driving in various conditions and modifying the fuel map to meet your application. For instance, in a manual maps system, your would look at the O2 sensor indication and determine where in the RPM fuel needed to be added or removed to maintain the correct AFR. PF4 does that on it own. It constantly monitors AFR and applies corrections as needed. There are plenty of things that you can play with to make it more to your liking. The distributor advance being a great one. The old days of removing and replacing advance springs to try and get close to the desired advance curve are gone. You can set initial timing, max mechanical timing, rpm it starts and is all in by, and vacuum advance from your tablet or phone. I run a PF4 on my 71 Corvette with the .030 over original 454 engine. There are plenty of other things you can tweak but I haven't had the need to mess with them.