ATTN: midnightriderZ24

[merlot566jka]

I cant seem to pm, it redirects me to the login page...that being said i have questions about your 4.3 throttle body modification...

I have the throttle body coming to me, but it will be a week or so before it gets here. I will be using it on a 3.4 in a fiero. I have the trueleo package, crane 272, heavy port n polish, 22lb injectors...and so on. I need the bigger tb.
I want to know what you did for the IAC and TPS. Since i dont have the tb here i cant see what it uses or has on it. I beilive i have the same style tps and iac as you on your 3400/3500 hybrid. the only difference is im obd1. i belive the tps and iac are the same from my 87 fiero, in that the tps reads 0-5v and the iac is the 4 pin, pintle valve type. does the 4.3 tb have the iac on it like other 60*v6 tb's? when mounted, which side of the engine is the throttle cable linkage on, cyl 2,4,6 or 1,3,5?
any pics or info would help. BTW i saw your initial post on the 4.3 tb, but it wasnt ever updated about the iac... just curious as to how you got it working and if it was working well.

thanks!

[IsaacHayes]

It looks like certain year ones probably are plug and play for IAC and TPS

http://www.v6z24.com/pictures/users/fallenz24/image/3500vs3100_2.jpg

Linkage on 246 side. Just get an adapter plate and then angle your linkage right and you should be good. It seems the linkage attaches 90* rotated more than a 3x00 does.

[merlot566jka]

thanks! a picture says 1000 words. i wonder if id have to adjust iac counts with the new tb....so that the comp doesnt over or under adjust the iac...

[IsaacHayes]

I would think the computer would learn. I swapped from a 52mm to a 56mm 3400 TB and re-used my IAC and the car idled high until it re-learned where it had to be. The IAC motor may be the same between the 4.3L and a 3x00 TB even? Maybe, maybe not...

[merlot566jka]

while the computer may adjust to get the target rpm, it wont be right in the programing. if the vacuum passage is smaller or larger than the stock the pintle may have to open more or less to achieve the same idle rpm...possibly throwing a code if the pintle has to either stay all the way down or all the way up to achive the target rpm. thats what i meant...

[IsaacHayes]

Right. My 3400 TB I actually had to grind open to look like the older 52mm one because they added a notch in the 3400 plenum that I do not have. I think the IAC area too was different but the same IAC motor worked. The new plate too didn't have a hole like my old one did in it.

The 4.3L however could be a lot different though and use a different IAC (but still function on the ECM).

I don't remember anyone mentioning having to adjust their ECM. But if you have the tuning ability to do so might as well take a look at the IAC counts and see where you are at.

[merlot566jka]

good deal....

[FallenZ24]

The iac and tps are all integrated into the t/b. I'm not sure if the plugs are the same as the fiero sensors, they should be though. I didnt have any problem with the comp. running the 4.3L parts. I did have to modify the throttle linkage to get proper leverage. This is in my 90z24.

Here's a little pic. You can kinda see the sensors and the massive size difference.


-Joseph

[IsaacHayes]

I looked at a 1500 truck that had the 4.3l in it last night. The IAC and TPS look just like my 3100 ones (connectors at least). The 4.3l TB sits on top like TB injection, with the linkage coming from the front.

So when it's bolted to out engines, you need the linkage coming from the bottom of the car straight up to the TB to match how it normally operates.