440 Mopar TBI Swap, Questions

Hey guys, longtime lurker and information leech here. I am installing a DIY TBI setup on a 1973 440 that's slightly warmed up and is currently living in a Jeep Wagoneer. I am using an early 454 TBI unit with the flat TPS connector and a '7427 PCM and harness that I got from the JY out of a 1994 G20 conversion van.

Here is where my confusion lies.

The BCC on the outside of the computer housing says BDSD. When I look that BDSD BCC up, I can only find it here: http://www.scotthansen.net/BCCLookup.pdf

BCC	Year	Release Date	Eprom	ECM	Prom ID	Scan ID	Platform	Engine	Displacement	Trans	Trans Type
BDSD	1994	33939	16188493	16168625	8494	8465	G1	LB4	4.3	M30	AUTO

I am almost 99.9% positive the van in the JY was a V8, not a 4.3, but it has been a while. The actual memcal inside of the computer doesn't show a BCC on it, just numbers. Those numbers are: 4090 1617 4891.

The ECM is a 7427 but I noticed something was amiss when none of the 7427 wiring diagrams were matching up properly. For example, F9 for me is an orange/black wire, which seems to match the $OE wiring diagrams. That makes even less sense considering the computer case BCC says it's for a 4.3...which wouldn't have had a 4L80...:confused:

Basically, I'm just looking for some detective work help in trying to figure out exactly what I'm working with. From my reading the 7427 can run either $OD or $OE, and since my harness seems to match the $OE diagrams and I'm going to use a 7.4L bin to start my tuning, is it as simple as burning the $OE info to a chip and going from there?

Quote:

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Originally Posted by WT91

Hey guys, longtime lurker and information leech here. I am installing a DIY TBI setup on a 1973 440 that's slightly warmed up and is currently living in a Jeep Wagoneer. I am using an early 454 TBI unit with the flat TPS connector and a '7427 PCM and harness that I got from the JY out of a 1994 G20 conversion van.

Here is where my confusion lies.

The BCC on the outside of the computer housing says BDSD. When I look that BDSD BCC up, I can only find it here: http://www.scotthansen.net/BCCLookup.pdf

BCC	Year	Release Date	Eprom	ECM	Prom ID	Scan ID	Platform	Engine	Displacement	Trans	Trans Type
BDSD	1994	33939	16188493	16168625	8494	8465	G1	LB4	4.3	M30	AUTO

I am almost 99.9% positive the van in the JY was a V8, not a 4.3, but it has been a while. The actual memcal inside of the computer doesn't show a BCC on it, just numbers. Those numbers are: 4090 1617 4891.

The ECM is a 7427 but I noticed something was amiss when none of the 7427 wiring diagrams were matching up properly. For example, F9 for me is an orange/black wire, which seems to match the $OE wiring diagrams. That makes even less sense considering the computer case BCC says it's for a 4.3...which wouldn't have had a 4L80...:confused:

Basically, I'm just looking for some detective work help in trying to figure out exactly what I'm working with. From my reading the 7427 can run either $OD or $OE, and since my harness seems to match the $OE diagrams and I'm going to use a 7.4L bin to start my tuning, is it as simple as burning the $OE info to a chip and going from there?

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Actually ALOT of G-vans and Express/Savana Vans had 4.3/4L80E drivelines. Even the newer vans used the 4L80E behind the little 4.8.

Huh, I never would've expected that. Learn something new every day. So I would guess that even though its a 4.3L, would it be a $OE PCM? I'm just not sure where to start with the programming/tweaking aspect. I'm running a 727 trans so obviously no trans controls, no EGR, no evap system, etc. So lots of disabling I have to do with whatever .bin I try to run, I was going to try a $OE 7.4L 5 speed program since that wouldn't have anything for the transmission.

So I have made a ton of progress and now have another question/concern. I have my setup "Running" on the truck. It seems to do well, but every so often the otherwise very nice idle just drops and the engine either stalls or struggles to recover. I have no idea what could be causing this. Fuel pressure is good, ICM is brand new, coil is brand new, timing is set at 4* advanced as per the 7.4L BMHK .bin I am using. I have corrected the .bin for the 74 lb/hr injectors I am using. I had some issues with a clogged fuel filter and then running out of gas :rolleye: but I have confirmed now that both the tank has fuel, the fuel pickup is sucking said fuel, and the filter is clean and filling with said fuel. I do see in my datalogs that there are some very strange spark advance numbers. Like 5000 degrees advanced at 2000rpm 45 map. Or 11000 advanced at 6800 RPM, which I have never revved the engine up to. I suspected the distributor, so I replaced everything in it. New magnetic pickup, new rotor, new cap. What could cause this? I am attaching some data logs...thanks...