tbi ecm difference ?'s
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Joined: Sep 2004
Posts: 206
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From: mount airy md
Car: 1991 caprice / 96 caprice
Engine: 4?? bbc / lt-1
Transmission: 700r4 / 4l60e
Axle/Gears: 4.10/ 3.73
tbi ecm difference ?'s
first thirgen board is absolutely great you guys really know your stuff. all of the other boards that i have been through all lead me back to here.
second this is kind of a long post so sorry just please bear with me
all appropriate mods have been made to vehicle in regards to properly supplying fuel to engine at the donor vehcles 11psi. and exhaust is longtube headers with cats an x pipe, and 2 1/2 dual exhaust
i have my 91 lo3 caprice with a 16136965 which i have since pulled and installed a 454 from a suburban along with its 8747ecm. the 8747 ecm starts and idles fine runs good, but i also have a 8746 i pulled from an 89 9c1. which one of these is better suited to run the 454 and keep all functions of the caprice. im not opposed to keeping the 16136965 and inserting all the data from the 454's prom, however i havent found a lot of support on the '6965. will the 8746 be a true plug n play? alldata , chiltons and my helms manuals dont ditstinguish between 8746 and 6965 in the wiring schematics for ecm connector. i know that the 6965 had a highway lean cruise and let me tell you that 305 sucked a**. my goal is to gain finer control over timing and fuel to get better driveability and yes fuel economy. ive ran a couple of tankfulls of this 10% ethanol crap through it but it still gets 21 mpg if i keep my foot out of it and dont use the a/c. i can burn chips and datalog. i have chips,tunerpro,moates autoprom and as soon as i can a wideband.
this is my daily driver, my wife sometimes drives it and she loves the 454. i might take it to the track once the engine is properly broke in and tuned to the point that i know it wont damage the engine.
i have searched and read throught the ENTIRE Tbi section, the Ecm section and have read through several times the info in the prom tuning guide looking for this info and have not been successful. even more info on where and how to search better will be great
any and all help will be greatly apreciated. opinions are welcome and will be considered.
i just realized i posted this in tbi if im in the wrong forum i apologize.
second this is kind of a long post so sorry just please bear with me
all appropriate mods have been made to vehicle in regards to properly supplying fuel to engine at the donor vehcles 11psi. and exhaust is longtube headers with cats an x pipe, and 2 1/2 dual exhaust
i have my 91 lo3 caprice with a 16136965 which i have since pulled and installed a 454 from a suburban along with its 8747ecm. the 8747 ecm starts and idles fine runs good, but i also have a 8746 i pulled from an 89 9c1. which one of these is better suited to run the 454 and keep all functions of the caprice. im not opposed to keeping the 16136965 and inserting all the data from the 454's prom, however i havent found a lot of support on the '6965. will the 8746 be a true plug n play? alldata , chiltons and my helms manuals dont ditstinguish between 8746 and 6965 in the wiring schematics for ecm connector. i know that the 6965 had a highway lean cruise and let me tell you that 305 sucked a**. my goal is to gain finer control over timing and fuel to get better driveability and yes fuel economy. ive ran a couple of tankfulls of this 10% ethanol crap through it but it still gets 21 mpg if i keep my foot out of it and dont use the a/c. i can burn chips and datalog. i have chips,tunerpro,moates autoprom and as soon as i can a wideband.
this is my daily driver, my wife sometimes drives it and she loves the 454. i might take it to the track once the engine is properly broke in and tuned to the point that i know it wont damage the engine.
i have searched and read throught the ENTIRE Tbi section, the Ecm section and have read through several times the info in the prom tuning guide looking for this info and have not been successful. even more info on where and how to search better will be great
any and all help will be greatly apreciated. opinions are welcome and will be considered.
i just realized i posted this in tbi if im in the wrong forum i apologize.
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Joined: Jul 1999
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From: Tempe, AZ
Car: 92 RS, 02 Tacoma, 2 73 Porsche 914s
what exactly are you asking? which ecm to use? I'd say not the one that isnt documented or widely used... the 8747 obviously has lots of tech info on it.
not sure which "functions" you want to keep from the caprice ecm. If i'm not mistaken the 8747 has high way lean mode too.
i'd use the one that works best NOW and that people have used extensively so they can help you tune in the future instead of say: "well, with my ecm i can do this... and it fixed that problem, but not sure if you can do that with the ecm you're using"
not sure which "functions" you want to keep from the caprice ecm. If i'm not mistaken the 8747 has high way lean mode too.
i'd use the one that works best NOW and that people have used extensively so they can help you tune in the future instead of say: "well, with my ecm i can do this... and it fixed that problem, but not sure if you can do that with the ecm you're using"
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