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Friend has a 460 that he is considering a tbi swap on. The questions I have are about the distributor. Right now it has the stock duraspark and module. how does this need to be wired to run the tbi. He would prefer to leave advance functional in the distributor with no computed timing.
He also has a DUI distributor for the 460 that he could use. can the 4 pin module be used to trigger the efi?
I don't understand why people want fuel only EFI. That leaves a lot of power and driveability on the table.
You need to make an adapter to be able to trigger the ECM from the coil or possibly an MSD tach trigger. I don't recal where I have seen this piece but I know one of the aftermarket EFI suppliers that Use GM ECMs supplied them.
You can also use the Duraspark to trigger the EST module mounted externally for full fuel and spark control.
There is also the option of machining a GM distributor, I have done these for just about any engine.
http://www.gearhead-efi.com/Fuel-Inj...BI-Conversions
What about using a 7 or 8 pin module externally, keeping the advance functional in the dist., and not connecting est to the module? Will the module still function correctly?
Why do it the hard way and backwards?
Lock out the advance on your distributor, run the wires from your Duraspark module to a 7 pin EST module mounted on a piece of aluminum for a heat sink anywhere, run those wires to ECM just like they would came from the GM small cap distributor. POOF! Fuel and Spark control!
What he said was that in the 2 454s that he has added tbi to, the fuel map was close enough (for what he used them for) but the timing curve really sucked. He ended up running almost 10* of base timing to get big block performance, but idle quality suffered because of the over advance at idle. He is expecting similar results with the ford, and being able to mechanically control timing would be easier than dealing with finding somebody and getting it tuned.
basically, poor people have poor ways.
Ah! I see... you want to do this without burning a chip... very strange concept for me? :homer:
OK so do it right, give me the spark curve you want and I'll mail you a chip for $50. How far are you from CDA ID? bring it here and I'll tune it right in person completly for $150. Or spend $150 and learn to do it yourself... you'd be set to do it over and over again.
I honestly don't know how to do it the wrong way? Somehow you have to get the EST module to send a signal to ECM to fire injectors, then you'd have the vacuum and mechanical advance from stock motor firing plugs. You can't just use the signal from the Duraspark as it needs to be a 5 volt square wave signal to ECM or you will fry the ECM, the EST sends the correct signal... so maybe that could be done?
Thanks for the offer. I guess it is probably time to learn to tune these, Is there a page on here that details what I need to get started?Quote:
Originally Posted by EagleMark
http://www.gearhead-efi.com/Fuel-Inj...to-New-and-OldQuote:
Originally Posted by black dawg
Thank you! and another question, If not using vss on this tbi swap (using 7747 454 stuff and no knock sensor) will the computer give full timing advance driving?Quote:
Originally Posted by PJG1173
Yes, as full as what is in the chip which can be changed. Other ECM/PCM are differant and have a seperate idle timing table and takes much more work to get to run without VSS.