Greetings from DE and a Jeep Nut

[jamessahm]

Greetings all,

I found this forum as I was NOT going to buy a bolt-on EFI product for my two jeep projects. I am not against these kits as they do serve a purpose, but after googling, I found that many have decided to roll their own vs. buy a whole kit. Me too. I like a challenge.

So, not a turn-key solution, but that to me is part of the fun of figuring it out.

I have a 1989 Jeep Islander YJ... 258/4.2L that will be getting a GM 4.3L TBI and spark control added to it with a fresh engine build.

I also have a 1984 Jeep CJ7 which at this point is nothing more than a VIN number. It's literally (and I mean literally) falling apart. Frame is gone, and collapsed in the rear... Body tub is gone... previous owner ripped out the Carter electric/onic carb and ran with a Motorcraft 2100 for it's life... Getting ready to pull motor, buy frame and get a rolling chassis going before too long. I have a donor YJ tub for it (same footprint), and some of the fenders/grill can most likely be saved...Anyway, this will get another GM 4.3L TBI transplant with spark via an HEI distributor.

Looking forward to some re-programming BIN questions when I get that far!

Thanks,
Jim

[dave w]

Have you considered the downside of using first generation TBI computer 1227747 vs the awesomeness of the second generation 16197427 TBI computer?

dave w

[amc360TBI]

Have you considered the downside of using first generation TBI computer 1227747 vs the awesomeness of the second generation 16197427 TBI computer?

dave w

What is the downside of the first generation and what is the advantage of the second generation TBI computer?

[PlayingWithTBI]

Have you considered the downside of using first generation TBI computer 1227747 vs the awesomeness of the second generation 16197427 TBI computer?

dave w

Or maybe even an EBL Flash-II?

https://www.dynamicefi.com/EBL_Flash.php

[dave w]

What is the downside of the first generation and what is the advantage of the second generation TBI computer?

The 1227747 is SLOW (160 BAUD). The 1227747 has timing tables up to 3600 RPM and Fuel tables up to 3200 RPM's. The 1227747 chip is only 4K bytes.

The second generation TBI 16197427 computer is about 50 times faster at (8192 BAUD). The 16197427 has two timing tables and two fuel tables Near Idle / Off Idle. Often 4WD vehicle owners favor tuning 4 Lo driving with near idle tables set at a maximum speed of 6 MPH. The 16197427 can control a 4L60E or 4L80E. The 16197427 has been "Hacked / Reverse Engineered" to control radiator fans and even control Port Fuel injection (8 injectors like the TPI). The 16197427 has timing tables up to 6000 RPM's and fuel tables up to 6400 RPM's. The 16197427 chip is 64K bytes.

The cost 1227747 vs. 16197427 is about the same (computer / harness) and custom programmed chips.

dave w

[1project2many]

Most folks replacing an old carb with EFI are tickled with the performance offered by the fuel-only Howell kits. I can tell you there's far more to be had from the 4.2l engines. A good conversion behaves very differently than a stock Jeep.

When used off-road I believe the 7747 suffers from idle control issues. The logic in the ecm seems to get confused with high engine rpm and low speed, or with frequent "on/off" gas pedal applications found in crawling and many trails. I've seen this in stock GM applications and I've discussed this Jeep owners. The 7427 is much more capable than the 7747 in many ways, and especially with idle control. The 7427 can often control idle acceptably in applications with no VSS and adding the sensor will only help. 7427's can also be used to control a 4L60E or 4L80E if you are desciple at the Altar of Eternal Upgrades. The 7427 is fairly common, coming from the factory in 94-95 GM trucks and in 93-95 Astrovans and a few S10 Blazers. Finding a V8 memcal may take a little more work.

If the 7427 isn't in the plan now, make sure you leave some room for change in your harness. I put EFI into my '57 Chevy back in 94 using an '83 Camaro ecm. Since then I've changed ECM's twice.