5.7 TBI Conversion - ecu troubles (broadcast codes) (1 Viewer)

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Hello,

Took a pre-TBI engine and put a TBI system on it (in a nutshell), All the sensors are new with a rebuilt TBI unit (possibly the most simple creation ever)... Anywho I am running a sm465 to toy case and no VSS or EGR and the broadcast codes for my ECM are for an automatic transmission but it is the most common 1227747, but with automatic trans broadcast codes. last time I had it running it idled smoothly and ran fine but surged and jumped under accel/decel which leads me to believe that it is the lack of EGR and probably most importantly the VSS but I'm not sure what else I'm missing. I believe I might need to get a new chip burnt, if anyone has a cheap source to figure out my dilemma that would be awesome
 
Joined
Feb 4, 2007
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Good evening, I can help. the 1227747 is a great ECM to use. I can help with the things that you need. what ignition system are you using? Howell Engine Development will burn you a chip that will remove the EGR and the VSS and anything else that yoou wont need, they helped me when I did a 74 Corvette TBI set up last year.
 
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Elbert

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Assume you have a knock sensor, a single o2 sensor. and you will only benefit with the install of a VSS, do you have your base timing set at zero degrees with the jumper wire disconnected. I think the TBI engines had a either a dedicated ECM for manual trans or different CHIP. You certainly will need a new chip "burned" if you are deleting required items.
 
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i'm using a knock sensor, single wire oxygen sensor, no VSS - stock computer and wiring harness from donor vehicle

saw the AFI's tuning fees are 395.00 - i'm not sure how relatively affordable that is, lol
 
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Nov 2, 2009
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If you are looking for flexibility with programming you should check out

DynamicEFI

ELB flash is a fully programmable ecu. Its a little expensive at $430 but it allows you to change every aspect of your tunning, spark tables ,fuel tables acceleration enrichment you name it. I had considered chip burning initially but this is so much easier for adapting to your engine and it has datalogging and realtime monitoring built in to the display.
 
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Mar 26, 2004
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Moates.net will have what you need to burn your own chips, along with a library of bin files to choose from. I believe that ECM had a run of years that used a 350/5.7 along with the manual trans. You can download Tuner Pro for free, to play with, to get a feel of what goes into chip tuning. The EBL is an exellent product, but your locked into " That " ECM. With tuning tools, you gain flexability to use on other vehicles. Check out the Autoprom on Moates. You can burn and erase chips, emulate and datalog all one one peice of equipment. Good luck
 

Elbert

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THe ECM on the tbi engine is totally differnt than the ones on the Vortec series...in that on the TBI engines if you make any changes from what the comptuer expects to see you need a new ECM chip "burned" or made to make those adjustments. On the newer engines you send the entire ECM off to have it reprogrammed to make those changes. One of the guys over on the 60 forum is a big fan of TBI engine performance..and recomends some guy that apparently does a lot of work on TBI chips. If were me I would leave the TBI engine basically stock, might install some 5.7 vortec heads and comparable manifold if $$ permited or some of the iron eagle heads by DART.

THe vortec is a simple setup compared to the new engines and its a very dependable setup. I don't think you can get it to run right until you get a new chip or you get another ECM/Chip combination that is like what you have..ie a ECM setup for auto trans and you run an auto trans.

VSS is required in my view.

do you have your base timing set to 0 degrees with the jujmper wire disconected. TBI engines very sensitive to base timing settings. THe one I had (GM pickujp) had to see 0 degrees at base timing.

I would run all the GM OEM sensors and stuff since they are very easy to deal with. I dont' think you are going to get reaonable power and drivability out of your swap until VSS is operational, and you get ECM either a ECM chip that recongnizes your modificaitons or you change to another OEM chip.
 
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Nov 2, 2009
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I went to

ThirdGen.org

and did most of my research on TBI conversion and tunning. They have a board for TBI prefomance, DIY PROM for tunning and there are guys on that have done everything you can imagine to their camaros and firebirds. Theu are a really good resource if you plan on doing any kind of tunning yourself
 
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wow .. when i got my chip just the chip.. i told them what i was working with as far as auto trans with vss no emissions rev limit what temp the fan comes on etc etc. i was only charged $100 or so .. it was for tpi ... check this out TOWMASTER CHIP Chevy 5.7L 350 TBI Truck 87,88,89,90,91 - eBay (item 400085927573 end time Mar-11-11 16:28:59 PST)
i'm using a knock sensor, single wire oxygen sensor, no VSS - stock computer and wiring harness from donor vehicle

saw the AFI's tuning fees are 395.00 - i'm not sure how relatively affordable that is, lol
 

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