have question on Edelbrock chip and mpfi kit off a 454ss truck

hey guys,
I've searched and read for a few days on and off and really cant find an answer to my dilemma.....I usually can read and figure it out, but im struggling here :-)
I have a 1991 chevy truck that has all the running gears from a 93 454ss truck in it..
previous owner had put the Edelbrock mpfi kit on it with the Edelbrock aluminum heads and roller cam,prob 10 years ago.
and looks like a new set of headers recently.
it had an msd on it, but I took it off and put it back to the oe ignition system, and it runs decent, but now I want to try to tune it.....it has the 454ss 4.10 14bolt rearend in its it should run ok with those heads I would think

I know its prob not a very good tune coming from a kit thats supposed to work on all tbi 7.4's.
universal is usually not good.

I bought the apu1 and used it successfully on another 454 truck I had, so im a little familiar with the process.

My questions are : can I read the Edelbrock chip that's in it, with what looks to be their G2 adapter, then write that .bin to a 27sf512,which I have, as a starting place? I read the chip thats in it, its a amd chip AM27C256-155dc with a UV window in it? am I thinking right to just keep that chip and use my 27fs512.

Or can I use tuner pro and my apu1 to drive it in emulation mode and modify it like that? wasn't sure I could write to this chip....did'nt want to mess it up till I had a copy(backup) to go back to, if I screwed up something.

or should I just load a good stock 454ss .bin,or marks $85 for those 7060 trucks, and then make the modifications to make the Edelbrock mpfi work, then tune from here?

I can read and datalog while driving and its definitely lean it seems, but when I read the Edelbrock chip and tried to compare the tables, spark and fuel, the Edelbrock chip read was all zeros......

so thats what made me think maybe they made it to where nobody could read it.

Hello and welcome to the forum.

You can use either the stock .bin or the Edelbrock file but there are many changes involved with converting TBI to MPFI correctly and the chip alone does not cover them. What number ECM/PCM are you running? If it uses a memcal then we can link you to the changes required to the hardware to correct the fuel delivery strategy.

As far as the calibration goes you might need to pick a larger chip. It's very possible the "bottom" of the chip is garbage and the "top" contains your file.

hey 1project2many thank you,

Hardware wise I'm good I think....the truck is running now and has been this way for 10 yrs.

Main thing I want to do is read the Edelbrock (old UV erase chip)chip thats in it now and then put it up.( I know it works and runs decent)

And the load that file to my 27sf512 chip and then use it for learning/tuning....that way I can always go back if I screw it up.



thanks mike

larger chip? garbage top and bottom?
if I'm understanding it right my new 27fs512 chip is 512mb,and the file I read from the Edelbrock was 32mb.
maybe I didn't read it right? I changed the hex address in flash & burn to 000000 so it would read the 256 chip. I read it and then hit verify and it said success and it was a 32mb file.
so your saying I read the chip in a different location than where the file was written?
I guess I need to read the offsets page again
What made me leery of it was I read it, and saved it....
then I opened it in compare, with the $85 16147060 .bin I have used on a regular tbi 454,and all the tables had the exact same # in all spaces, the entire VE table was 0's
or timing vs ect was all 12.5.....just weird,
so I thought maybe they had done something to keep people out of it back then.....I don't know.
I guess I could write the file I read from the Edelbrock chip to a blank chip and see if it runs like the old one

ok so how would I figure out the hex offset or value to be able to read the chip in the right address?

its a amd chip AM27C256-155dc with a UV window in it

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Originally Posted by mike454

larger chip? garbage top and bottom?
if I'm understanding it right my new 27fs512 chip is 512mb,and the file I read from the Edelbrock was 32mb.
maybe I didn't read it right? I changed the hex address in flash & burn to 000000 so it would read the 256 chip. I read it and then hit verify and it said success and it was a 32mb file.
so your saying I read the chip in a different location than where the file was written?
I guess I need to read the offsets page again
What made me leery of it was I read it, and saved it....
then I opened it in compare, with the $85 16147060 .bin I have used on a regular tbi 454,and all the tables had the exact same # in all spaces, the entire VE table was 0's
but it runs, so I know the proper info is in there somewhere

so I thought maybe they had done something to keep people out of it back then.....I don't know.
I guess I could write the file I read from the Edelbrock chip to a blank chip and see if it runs like the old one

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I'm not very familiar with using the :moates" flash chip(it's EEPROM instead of EPROM(with a window)EEPROM = electronically eraseable prom, EPROM = eraseable(UV) prom, I think I tested it once. The 7060 uses a 27256 chip which is 32K, the moates 27512 chip is 64K .....kb not mb. I do believe you are supposed to load the bottom of the 512 chip with your 256 data. I'm sure others better versed in this will be by shortly to better explain.
p.s. No, edelbrock did nothing to stop you from reading it.

yes thanks In-tech....
autofill gets me all the time.
I did see that it was kb after the fact.
ok cool, like you said im sure I just read the wrong area.

its a lot for a newbie to wrap my head around, but I'll get it with a nudge in the right direction.lol

For starters,...I guess where to look up the hex addresses I need to use to read this chip. its a AM27C256-155DC 103V9XC @1986 AMD and it has a UV erase window

well I set it to 27fs512(read only) and it read it..

can one of u guys look at it and see if looks like it read it right?
thanks
mike454

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Hardware wise I'm good I think....the truck is running now and has been this way for 10 yrs.

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Yep. It runs. But it might lead to an interesting discussion if you consider why GM spent millions of dollars designing ecm code and memcals to deliver fuel differently if the engine is equipped with port fuel injection or throttle body injection. I've driven a BBC suburban with the Edelbrock conversion. It was not impressive. It stumbled, ran rich, and didn't lean out during decel. Those seem to be common complaints from others but maybe yours is different?

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can one of u guys look at it and see if looks like it read it right?
thanks

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At a very quick glance it looks like the read was correct. The mask or program ID at $0008 is $D8 which matches up with 16147060 or 16127470 ecm in 91-93 trucks and the end of the file has appropriate looking reset and code entry addresses. If you can find a D8 definition file for Tunerpro then you should be able to view the data.

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its a lot for a newbie to wrap my head around, but I'll get it with a nudge in the right direction.lol

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It is a lot. And it will come at you fast. But feel free to ask questions. We're all students here...

oh yea defiantly,i knew the Edelbrock kit was a bit of a rube goldburg apparatus,considering it was designed to run tbi not mpfi. I didn't think a couple wire and a chip tune would/could do a whole lot.
I figured it was kind've a patch up deal to wire it to fire bank to bank like the throttle body did.
I know to do it right it would need to be ran as sequential to make it run optimized.
so if there is a way to get there hardware wise id defiantly be looking to go that way..
I just wanted to save that Edelbrock chip read just in case during all this I couldn't get back to where it was.(which aint the greatest)
im not sure what's actually on there....I got it to read right by just checking the 27c512(read only), it wouldn't read using the 27c256 no matter which offset I used./

who knows I guess some where down the line it may have been changed or rewritten anyways.

Thanks for taking a looks will go look it over in the compare and see if I can figure out what they did.

mike454

Been some time since I had that system. Wester's Garage cleaned up Edelbrock's tune before I moved on to DynamicEFI.

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I know to do it right it would need to be ran as sequential to make it run optimized.

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Sequential is not necessary. With TBI the injectors are fired left bank, right bank, over and over, most of the time. PFI mode gives time between injection events for fuel to vaporize.
There is more [rul=https://web.archive.org/web/20030216033345/http://www.fortunecity.com/rivendell/oddworld/24/ECM/inj_op.htm]here.[/url]