Shade Tree Wrench'n on a TBI swap North of Lat 48

[48Njim]

Actually, wrenching under a Big Sky or Ponderosa pine would be more accurate here in Northwest Montana.

Bringing an old project up from the back burner. It's a '65 Toyota Land Cruiser with '69 Camaro motor and TH350 AT. About ten years ago I tossed the Quadrajet and installed a TBI from a '88 Chevy Astro Van. It worked and has been good enough for the old Cruiser although it still spent too much time parked. Too many other projects...

Facts:
'65 Land Cruiser FJ40 with
'69 Camaro 350(5.7L)/300hp w/TH350 auto with
'88 Chevy Astro Van ECM (4.3L V6)
SVC# 1227747
Prom: AKMH

Questions:
Which ADX file should I use for ALDLdroid?
The engine is 5.7L V8 but the prom is 4.3L V6. Match Engine or the Prom?
Should/could I swap installed Prom for a variety more appropriate for the 5.7 engine?
Could tuning the existing chip get similar results?
Should I change injectors to match the 5.7? Fuel regulator?

Hopefully that gives you an idea of why I am here. I'm looking forward to your comments and advice.
Thanks in advance,
Jim
48Njim

[1project2many]

Hello from a former MT resident. That sounds like a fun project. Congratulations on getting it running!

I would recommend two changes. First, there is a small, socketed chip inside the ecm called a Calpak. The Calpak contains the backup programming but also contains information the chip uses to know how many cylinders the engine contains. Using the six cylinder Calpak with an 8 cylinder engine causes the ecm to believe the engine is operating at the wrong RPM. This can make it very challenging to tune the engine. This post on thirdgen.org has a picture of the eprom and of the Calpak.

Second, start with a calibration already set up for an 8 cylinder engine. V6 calibrations are very different. They decelerate more slowly, they idle a little faster, they don't really use the same strategy for delivering fuel... I honestly have had better luck starting with V8 calibrations even on old inline six retrofits.

Fuel injectors should match the engine power output. Some V6 engines used two different TBI injectors and few made the same level of power as your 350. I would use one of the basic fuel injector calculators on the interwebz to get a recommended injector size and buy injectors that deliver the correct amount of fuel.

You may be able to erase and reburn the original chip. Many of the OE chips were finicky and wanted different programming voltage than more common industrial chips. EPROMS are old technology. If you are going to use EPROM's you will want both a burner and a UV eraser. 2732A's are compatible with the 7747 and are still available, used, from Jameco 2732 family chips are *very* sensitive to static charges. I would advise learning to ground yourself and getting used to following procedures for handling chips to reduce static discharges.

You can reduce the amount of equipment needed by switching to a newer flash style chip. These can be erased by the same equipment that programs them. A 27FS512 is what most folks used to use but it is not pin for pin compatible with the original chip. You will need an adapter and soldering skills to use this. There used to be a company at moates.net that sold a pre-made adapter, the G2. They would also install the adapter for you for an additional fee. Moates is no longer in business but maybe there are other folks that will sell you the parts and / or install an adapter for you. With used EPROMs available and relatively inexpensive, and with better ECM's available that are easier to tune, I would not recommend converting the 7747 to flash chips.

The 1227747 uses $42 definition file. There is a nice definition file in this thread.

You might also want to consider switching to a newer PCM. The 16197427 / 16196395 PCM's are used with 94 and newer v6 and v8 trucks and vans. They provide more data, and faster, when you are trying to make changes. The 7747 to 7427 swap has been done many, many times. Here's a long thread for reading at the end of a busy day.

[48Njim]

Hello from a former MT resident. That sounds like a fun project. Congratulations on getting it running!

Thank you, yes it's all about the fun. I'm amazed the original conversion from the Quadrajet to the TBI years ago went so well without really knowing what I was doing. I mostly remember sorting out wiring for the original Toyota, carbed V8 swap and Throttle Body EFI conversion. Looking back I feel lucky. Obviously it's a forgiving system.

I would recommend two changes. First, there is a small, socketed chip inside the ecm called a Calpak. The Calpak contains the backup programming but also contains information the chip uses to know how many cylinders the engine contains. Using the six cylinder Calpak with an 8 cylinder engine causes the ecm to believe the engine is operating at the wrong RPM. This can make it very challenging to tune the engine. This post on thirdgen.org has a picture of the eprom and of the Calpak.

Excellent explanation. I just learned the importance of both chips thanks to this response from Dave W.

Second, start with a calibration already set up for an 8 cylinder engine. V6 calibrations are very different. They decelerate more slowly, they idle a little faster, they don't really use the same strategy for delivering fuel... I honestly have had better luck starting with V8 calibrations even on old inline six retrofits.

As noted in the referenced thread I'm working on procuring 1227747 ECM with ASDU chip (and the proper Calpak for he 5.7L V8)

Fuel injectors should match the engine power output. Some V6 engines used two different TBI injectors and few made the same level of power as your 350. I would use one of the basic fuel injector calculators on the interwebz to get a recommended injector size and buy injectors that deliver the correct amount of fuel.

I am also getting a pair of injectors for a 5.7L motor.

You may be able to erase and reburn the original chip. Many of the OE chips were finicky and wanted different programming voltage than more common industrial chips. EPROMS are old technology. If you are going to use EPROM's you will want both a burner and a UV eraser. 2732A's are compatible with the 7747 and are still available, used, from Jameco 2732 family chips are *very* sensitive to static charges. I would advise learning to ground yourself and getting used to following procedures for handling chips to reduce static discharges.

You can reduce the amount of equipment needed by switching to a newer flash style chip. These can be erased by the same equipment that programs them. A 27FS512 is what most folks used to use but it is not pin for pin compatible with the original chip. You will need an adapter and soldering skills to use this. There used to be a company at moates.net that sold a pre-made adapter, the G2. They would also install the adapter for you for an additional fee. Moates is no longer in business but maybe there are other folks that will sell you the parts and / or install an adapter for you. With used EPROMs available and relatively inexpensive, and with better ECM's available that are easier to tune, I would not recommend converting the 7747 to flash chips.

Thanks for the summary. I'm starting to get my head around these details but it's as if the version in my mind has every fifth word redacted.

The 1227747 uses $42 definition file. There is a nice definition file in this thread.

Got it.

You might also want to consider switching to a newer PCM. The 16197427 / 16196395 PCM's are used with 94 and newer v6 and v8 trucks and vans. They provide more data, and faster, when you are trying to make changes. The 7747 to 7427 swap has been done many, many times. Here's a long thread for reading at the end of a busy day.

Thanks for advice. Perhaps I jumped the gun on getting the second 1227747 ECM. This may be the next phase. My primary desire to get into the chip programming stemmed from the deleting the annoying EGR code.

Thanks again for all the information, it really helps to put these pieces together. Who knew morphing pieces of obsolete technology could be so much fun?
Jim