Chevy & GMC Vans

Was wondering if any of you might be able to identify this TBI system. Every time i go to the auto part store? they give me the wrong part and we keep arguing about it.

I know for sure i took that one off my old boss's 94 Suburban 4x4 C1500 as i needed that tbi for the conversion for my Astro into a V8. Now i have a Vacuum leak and looking to get another TBI system and no one gives me the right one.

If anyone here are able to identify where and year and model of the vehicle that came from? you will be a saviour.

Some of the TBI system, the Accelerator cable clips on the throttle, as you can see, mine wraps around it.

And OH SHIT, maybe i put the wrong throttle in it, Have I? looks like a V6 throttle with a V8 injectors, that could be my problem, or maybe i'm loosing it.

TIA

Angel

Well, i should of known better.

i have a new set of a tbi system coming for the van and looks like my no power was from day one. i have the injectors right, but not the tbi as i wanted to re-use the throttle cable for the van use the same tbi "ie V6" so looks like i have a ratio issue of air fuel as we all know that V6 have a smaller bore than a v8.

So will be picking up my tbi today and work on my beast this week end. Cant wait for a full power

Take a peek at this link:

www.TBICHIPS.com

1Gary wrote:Take a peek at this link:

http://www.TBICHIPS.com

Thanks Gary, will give it a try. ;)

My understanding is that the SBC and 4.3V6 TBI are the same body with the same bore but different injectors.
The only Body with a bigger bore is for a BB 427/454 etc.
BTW, your throttle cable looks nothing like mine (87 & 90), not even close.
Mine, (all 3) have a plastic "Cable" not a metal "Cable"
Jus sayin....

doyoulikeithere wrote:My understanding is that the SBC and 4.3V6 TBI are the same body with the same bore but different injectors.
The only Body with a bigger bore is for a BB 427/454 etc.
BTW, your throttle cable looks nothing like mine (87 & 90), not even close.
Mine, (all 3) have a plastic "Cable" not a metal "Cable"
Jus sayin....

That's what I now recall about them too.When I bought my V8 Astro donor van,the TBI had 65lb injectors lifted.What TBI Chips does is re-chip and preform work to smooth out the TBI and narrow the throttle shaft.The limit of TBI's is they don't like cam center line over 112.More like a 114 is better.In fact cam profiles should be within 10% of OEM.So to get a 400 hp TBI is a crowning achievement.Actually most end up at 350hp or alittle less.The TPI's are alittle better,but are all done by 4500 rpm to 5000 rpm.The other thing that is a limitation is the size of the V8.The 383 strokers is a issue with OEM EFI's and the aftermarket stuff is very expensive.A Eldelbrock new in the box will cost $3500 or more.The Fast systems are in my mind a nickel dime go broke same costs at the end of the day.All along with my 383 project I wanted to go EFI,but given the costs,I haven't decided what I am going to end up using.I do remember a Ohio member we had with a 355 V8 that did the conversion to carb and regretted it.Lockdoc had a crate 350 cammed correctly that was pretty stout.He did alot of the mods himself to the EFI.Not many plug and play situations unless you duplicating the OEM EFI.

doyoulikeithere wrote:My understanding is that the SBC and 4.3V6 TBI are the same body with the same bore but different injectors.
The only Body with a bigger bore is for a BB 427/454 etc.
BTW, your throttle cable looks nothing like mine (87 & 90), not even close.
Mine, (all 3) have a plastic "Cable" not a metal "Cable"
Jus sayin....

Interesting reading from your post and Gary's, not saying that you were wrong or anything, but i have heard from my mechanic that they do have a different size for the tbi from a v6 and from a v8 motor.
I have replaced my Injectors to a v8 and did replaced the ecu off a 94 Suburban and i always some issues "read my previous post on my project" that it always ran rich since the day i got her back on the road and never replaced the tbi system on the motor. i bought another accelerator cable "off a 90 safari van" for my van as the one i have simply wont fit on my new tbi system.

I could shave my tbi system to gain an extra 50 CFM, but i don't think it would solve the issue of what the real problem is.

My mechanic said anyway that my timing was dead on, all my ignition are working properly and all the reading off my sensors are showing properly. Fuel pump was replaced, o2 sensor and so as the fuel filter and the problem is still there.

So come down to the conclusion that the TBI is the only thing that i haven't replaced and that could and hoping that is the main problem from day one.

will install it either today or tomorrow and will go from there.

ANyone knows which Accelerator cable should be used on the Astro van? i ordered one off a 1990 safari van and it is a little short even though the cable is about 60" long, my throttle is a little open when i start the motor, Maybe a G30 1 ton van might do the trick?

Also have a New Holley Intake manifold and put the Brass looking adapter to take those kind of V8 acc cable

All TBI units are the same bore and such until you go past the 5.7/350 engine in size, The Injectors are different I have a list of numbers and flow rates and such in another PC in my garage. the linkage you show I believe is 90 to 95. SO you can use the TBI unit from the original V6 and swap the V8 injectors on to it with a rebuild kit from rock auto or TBI specialties. and then use your original cable. I have rebuilt/modified 5 or 6 tbi units they are simple to do. If you were closer to me in California I would rebuid it for you free you just buy the parts. I prefer TBI over all other types of fuel systems so far just because they are simple to troubleshoot and fix.
If you want the flow/part number list let me know

markinnh wrote:All TBI units are the same bore and such until you go past the 5.7/350 engine in size, The Injectors are different I have a list of numbers and flow rates and such in another PC in my garage. the linkage you show I believe is 90 to 95. SO you can use the TBI unit from the original V6 and swap the V8 injectors on to it with a rebuild kit from rock auto or TBI specialties. and then use your original cable. I have rebuilt/modified 5 or 6 tbi units they are simple to do. If you were closer to me in California I would rebuid it for you free you just buy the parts. I prefer TBI over all other types of fuel systems so far just because they are simple to troubleshoot and fix.
If you want the flow/part number list let me know

Ya Thats right Mark. some of my vans have a round clip cable end, and the big block chevs with OBDI TBI have a larger different Throttle Body with bigger bores.
the OBD-I 4.3 and SBCV8 use the same Throttle Body and even the same computer box with diffrent chips.
I bought a chip, matched injectors, and shaved off the TBI's bumps and lifted the injector pod up as well. It still runs
here is a link with pictures that shows how to instal OBDI TBI on any SBC engine or 4.3. They even use use thame number computer box as I have.
http://www.gearhead-efi.com/gm-ecm-pcm- ... rsion.html

So, Aqua, You can use an Astro Throttle-Body unit like Mark said, and put V8 injectors on it.
Make sure the injectors you use are for a v8 of the same size as you run cuz 262 & 305 & 350 & 400 Injectors flow at diff rates.
Also (I assume you already did?) be sure to get the right V8 Chip for your OBD1 Computer box. Dont rely on a mechanic to do it for you.
What number was the Computer box you used?

Now, If you talking about the OBDII Throttle bodies, those are different again completely !

As of my current setting? i took a V8 throttle with an older V8 injectors, i have a rebuild one sitting in my van still with a V6 throttle body. Still made no difference. i will put back my V8 injectors with my V6 throttle back in it.

As for the chip? i used a 94 chevy suburban 4x4 ecu for my beast. to get the number, i'll have to take the kick panel out again, but it was running fine before, wondering if my O2 sensor could be faulty.

if you need a 7747 ecm I have a few extras but no extra V8 chips just let me know. Any time I do a V8 swap I use as much of the doner parts as possible get it installed and check everything prior to changing any parts such as a better intake, headers etc. that way I know if anything is messed up such as a gasket or whatever prior to spending more money. Good luck, Mark