Making a '80 406 into a TBI thoughts..

[rockosocko]

I have been driving a '95 Cheyenne 2500 5spd for a few months and either a head gasket or head just went (007 white smoke and water in oil)

Ok, so I've been messing with cars/machinery for a few decades and have built up 'resources' of parts.
The truck was showing about 320K and don't know if it's the ACTUAL mileage of THIS motor.
My options are to build up a roller 5.7 with fresh, self ported Vortec heads (hope it just needs a hone and bearings (?) and a Vortec carb intake with a TBI adapter for the throttle body, and a 210/214 Lunati bare bones roller. Pretty much a WHOLE build.

OR, a balanced 406 that I built up about 18yrs ago using Chevy High performance build as a guide, with NEW -at the time- Trick flow heads, -18cc?? dish's and a EX284 cam. (It's been sitting in plastic, and almost afraid to look at it hoping it's not rusted..)
I would have to get a manual flywheel (and TRY to find the balance card) for the NV4500 and pray that it all would 'play nice', and swap out the cam for a EX268. And again use the adapter plate for the throttle body.

What I never read in threads or hear on the youtube vids is what they (people that swapped either Vortec heads or used built up motors) did to ACTUALLY get their TBI system to accept the new transplant.
I've read too many threads of company's like TBIchips.com leaving people hanging with a motor that won't run like what they wanted, or remorse of spending $$$ on stuff that doesn't work.
Actually have a good bud that's going through it right now. $200 and sending chips back and forth wasting time.

SO, what messes up the TBI system? Whatever motor that I use, it will be a fairly small cam, and the TBI only reads temp, 02 and ignition right? (well, map too)
(if I had the money, I'd get the FI-Tech injection and be running.. IF i had the $$$)
Also know buddy's that have installed headers/full exhaust and said ran great with NO problems on EGR!

It's meat to be my daily driver, and WANT to be back up and running before too long.
This happened at a real bad time. So I kinda need assistance pretty quick..

Thank you.
Errol

[Tom]

Well, a hone and bearings is far from a full build on the 350 IMO. More like a freshening. But the 350 will be easier to tune for I'd imagine. As long as you find a good tuner or learn yourself the 400 won't be an issue. There were TBI 454's from the factory so it can obviously work.

[Kudzupatch]

I am going through this thought process too. I have read a good bit. I am looking for a little more power and torque for my Suburban. The conclusion I have come to is TBI is not for a high output motor and many people put together a motor that is not TBI compatable and then try to tune it mail order.

The biggest issue with doing something different is finding someone that can tune your computer, in the case of TBI it's a chip for the computer. I think the guy at TBI chips has the skill but trying to do it without the car in hand is a bad idea. Without seeing what the car is doing I don't see how you can adjust the tuning. So if you going to do something different you better find someone that can tune it for you or you may be wasting your time and money.

[rockosocko]

This WASN'T planned for. So it's like a panic trying to find someone close and who can be trusted.
I've asked on a few sites that I'm on but it seems that people have moved on to the 5.3 tuning and don't have the programs or burners any longer (the ones that I know)

It's a little strange that this technology is close to 30yrs old and one would THINK that there would be a system or program(s) to easily tune a TBI.
By "easy" I mean under 200.00 and within a few hours. Heck, the ricer kids can do all sorts of stuff with their ol OBD-0 stuff..

I know that the Mega-squirt gang can control LT-1 stuff, but haven't read of the TBI stuff.
Looky here..
https://www.google.com/search?q=can+...ddress&ie=&oe=

Kudzu: look into the FI-tech on youtube. It might be good for you.
I would if I had the funds and flywheel for this 406.
Errol

[Mr_Rich]

I think you have to start admitting that these trucks of our are obsolete. Look at the evolution of computers and cellphones and compare. I hate to admit this myself but it's reality. Three years ago I swapped out my flat tappet cammed 350 with a roller cammed 350 I had stored in my garage for eighteen years. I squirted oil in the cylinders and turned the crank every so often during that time and when I was ready to use the engine I replaced the seals and installed the engine. It's been a damn good engine these last three years and I have over 50K since I installed it. I also got 20 mpg multiple times on a trip to Texas last year. A roller cam alone makes a big difference in an otherwise identical engine. It sure made a difference for me. Now if you're set on even more performance I might suggest checking out the ThirdGen.org (Camaro & Firebird) message forums. I believe they're still pretty active with tuning issues with these GenI engines.

[Marv D]

This is exactly the problem when you start 'hot-rodding' these trucks. FEW have the burner or the blank OBDI chip to burn,, and if you find the hardware to do it,, the guys that have the expertise are FEW and VERY far between.

Here is one option (although I have not personally used this), it looks to be sound option. Actually I found this link from another thread here in this forum.

http://www.dynamicefi.com/

I built a 383 for my 94 4x4 using a roller block, RHS vortec heads, modified a GMPP Vortec intake to accept the 500cfm Holley throttle body, and had 3 different shops that were "THE GUYS of the day" for OBDI burn chips for it. It's STILL not exactly right and after 10 years I will either dump the TBI and slap a carb and HEI on it,, or give the dynamic EFI guys a try. Looks promising

[SCOTI]

I have a similar situation so I'm watching & investigating info from threads like this. My 90 4.3/5spd is worn. At 240k on the original parts, blow-by is the main issue.

It still has good pep in it's step but I've been watching for easy swap options. I considered a 350 roller block swap but it's hard to cough up money for that when I have a decent 509 .030 over 400 short block sitting on a stand in my shop (from a previous transaction). I would really like to swap it along w/a 700r4 (I know the nv3500 wouldn't live very long w/any 'fun').

I could retro back to a carb but I like the 'get-in & go' reliability + efficiency OE TBI offers. The FI Tech set-up looked promising but I've heard/read of issues (cold start, accel/decel stumble mainly) & other 'self-learning' set-ups move you into the higher cost group almost to the point where you consider an LS swap.

Sure wish there was an EASY button w/these early CC set-ups.

[Twin Turbo Skylark]

Hi there, I have quite a bit of experience with the TBI engines, chips, upgrades and all that stuff and here is some info that may help:

1. It is the larger camshafts with changed vacuum readings that throws off the TBI
2. Plus it is a rudimentary setup that just cannot adapt on the fly like the new stuff can. It is pre-programmed with the chip and thats that.
3. I used a few custom chips in TBI 350s after I made upgrades and I never was happy with how it ran. I always went back to the stock chip.
4. The TBI system is low on CFM, about 470 CFM if I remember correctly, maybe 500 but no more. Yes you can use a 454 TBI but thats bunch of hassle for little gain I tried that just got worse fuel mileage.
5. Megasquirt works well, I had that on a TBI engine no problems... Paid a guy to dyno tune it and it was perfect, much better than the chips in the stock computer. Plus you can upgrade the EFI system and keep the megasquirt.
6. The TBI just isn't the best performance over 4000 RPM, under that it is great. It is simple, low cost, easy to troubleshoot, just 2 injectors, reliable, reliable, reliable.

I even had a 90s Chevy truck with a 383 and a Holley 670 TBI and it was using the stock computer and it actually ran better when I swapped a stock small cf. TBI back on it needed extensive tuning to run right and it was not worth the hassle to me.... Got the truck for $1200 because it ran like crap, swapped on a stock TBI, and it ran perfect and sold for $3000.

If it were me i would setup a run stand and try out that built engine you already have. And if you are not sure about the balance then just take it apart, clean it up and you may need a hone anyway if it sat that long. Try the engine out of the truck, and have a flywheel match balanced, or the assembly balanced whichever way you need to go. You say you have a balance sheet I am guessing that is your bob weight? Was the engine balanced internally or externally?

The NV3500 is a pretty stout trans, I would not swap that out for a 7004r no way! I understand the gains of an auto don't get me wrong but I would buy a different truck before I did a manual to auto swap.

Oh and one last thing... Fitech is a good setup, but there are lower cost options for aftermarket TBI and they all work really good. It is not like it is a race car, for a street driven truck even the low cost TBI setups are really good these days. 8 years ago when I was messing with GM TBI stuff we did not have an option for the low cost aftermarket stuff.