Hi All,
I think I'm going to install a TBI system onto my cruiser with Chev small block. The local pick-n-pull had several trucks with Thottle body injection. Are there any models I should avoid? Any particular ones I should look for? I did not see anything that had the weatherproof underhood ECM.

Found:
1. 87 chev 350 3/4 ton truck w/manual trans
2. 88 chev 350 3/4 T van w/auto
3. 90 chev 350 3/4 T van w/auto

I was looking at the trucks because I would think they were programmed more for performance rather than emissions, and the gear ratios would be closer to what is in the cruiser.

Price was $225 for everything I needed to do the changeover (I pull)

You buying the whole truck, or just the TBI unit? $225 sounds pricey to me for just the TBI, but your market may bear it.

(bought an entire 1991 Chev conversion van for $200 this winter....major deal!)

IMO, it won't matter. However, check a couple of the links on my site...IIRC, there's one for do-it-yourself EFI.....something like http://www.diy-efi.com or something....good place to start.

You will likely need a custom program regardless of which setup you choose. But you are correct the truck with manual will be closest to what you need. It will run regardless, just how well is the question.

Wonder around the customefis (http://www.customefis.com) web site. Take a look at the Jeep install.

I would stick with the 1227747 computer. Lots of information can be found on that TBI controller on the GM-EFI (http://www.diy-efi.org/gmecm/) web site. That is not a weather proof version. Hmm, I know the TPI came in both standard and weatherproof versons (1227730 & 1227727, just not sure about a weatherproof version of the 1227747).

I would go with the manual tranny version. Don't forget the fuel pump (about a 15psi on the TBI installations) when grabbing everything else.

Cheers,

Tom :usa:

All three of the trucks I listed had the 1227747 ECU in them. I'll prob need an aftermarket fuel pump as these are all inside the tank.

Another ? , what is a "V" series truck? The 87 is a V20. I thought the PU was either a C or K.

Originally posted by roundrocktom
Wonder around the customefis (http://www.customefis.com) web site. Take a look at the Jeep install.

I would stick with the 1227747 computer. Lots of information can be found on that TBI controller on the GM-EFI (http://www.diy-efi.org/gmecm/) web site. That is not a weather proof version. Hmm, I know the TPI came in both standard and weatherproof versons (1227730 & 1227727, just not sure about a weatherproof version of the 1227747).

I would go with the manual tranny version. Don't forget the fuel pump (about a 15psi on the TBI installations) when grabbing everything else.

Cheers,

Tom :usa:

Never use a manual TBI chip on anything, manual or auto. The throttle follower logic in the manual chip keeps the idle speed very high when coasting to a stop. Without a speed sensor, it sometimes will never come down. www.tunercat.com has a new program called CALDATA that will tell you what year and spec each GM chip was used. you can download a bunch of 7747 binary files from www.diy-efi.org and check each one with CALDATA. I always try to use the last year I can and always avoid files that has tech service bulletins associated with them. By the way Tom, if there is anything you would like me to improve in my manual, I'm all ears.

customefis.com

Originally posted by tpiguy


Never use a manual TBI chip on anything, manual or auto. The throttle follower logic in the manual chip keeps the idle speed very high when coasting to a stop. Without a speed sensor, it sometimes will never come down. www.tunercat.com has a new program called CALDATA that will tell you what year and spec each GM chip was used. you can download a bunch of 7747 binary files from www.diy-efi.org and check each one with CALDATA. I always try to use the last year I can and always avoid files that has tech service bulletins associated with them. By the way Tom, if there is anything you would like me to improve in my manual, I'm all ears.

customefis.com

Hey, where did you come from? :) Noticed you registered a couple of years ago, but have only 8 post... man, talk about a lurker.

How well do you know the VORTEC MOTOR'S? Trying to get a good idea of what motor was fitted with which efi system.

Thanks for the tip about the manual tranny VSS & IAC. Yep, IAC is used in coasting to reduce HC emissions.

Hmm... what to improve on the EFI Manual... Hmmm... Just need for you to come to Austin and buy me a beer! I still have my '747 computers, 16500 logic analyzer with pattern generator and capture, and break out boards... could have a field day! :D Seriously ZERO TIME to do stuff as the kids are getting older. Funny last time I was active on DIY_EFI was in '95 (????). Oh, yes I did sell the Jeep (wonder if anyone noticed the custom machined carb?)... :)

Tom :usa:

FWIW, there is a really good Toyota Trails article from about 2 years ago all about which years of EFI GM engines are better and why, comparison, what you should do for each swap, etc etc. Really in depth. If I can find it I will at least tell you where to look. They say the earlier ones are easier mostly because of theft-prevention devices impremented into later years. I hope it helps...

Originally posted by dieselcruiserhead
FWIW, there is a really good Toyota Trails article from about 2 years ago all about which years of EFI GM engines are better and why, comparison, what you should do for each swap, etc etc. Really in depth. If I can find it I will at least tell you where to look. They say the earlier ones are easier mostly because of theft-prevention devices impremented into later years. I hope it helps...

The anti-theft is easy to defeat with a chip programmer. The thing I stay away from are the LT-1 ECMs and any other flash ECM for that matter. It is very easy to wipe out a flash PCM with nothing more than opening the car door. If there is one glitch when programming an LT-1 PCM, the PCM is toast and costs $200 to repair. Any GM truck after 1995 had a flash PCM. That would be all the Vortecs. The Vortecs used what is called CPI, Central Point injection. It was a cross between TBI and port. I dont mess with it.

Tom, I was alerted to a poster here who hacked my Ebook. I came here to see what it was all about. I am normally too busy building EFI kits to hang out much on these forums. I will now only sell the manual in paper form thanks to him.