Technical Throttle body replacement (Punto 55 tuning)

[Rubi]

OK, I got a 38mm throttle body from Punto 75, which . I also have a Haynes Manual on Uno, covering a 1108cc engine, with some instructions about dismantling the injection/throttle body, but not in great detail.
Does anyone have experience with replacing the 32mm throttle with the 38mm one? Is it just a "screwdriver and spanner" operation, or it requires some cutting/milling/drilling etc? I'we read a few threads about it on Cinq forums, but now I need some precise advice. All help is wellcome.
Thanks,
Rubi

 

[dave]

did you know the 75 is an mpi and 55 is a spi, most on here get their spi ones bored out to 40mm

 

[Rubi]

I'm aware of it. I'm not changing the intake manifold, nor the injector/ECU. The injector/temperature sensor is located on top of the throttle body, and the manifold is under it.

The question is - are all the tubes/wires/sensors/gaskets/bolt positions/etc. absolutely the same, or is there some work to be done modifying those?

I have a bare "throttle body", just the casing with one moving part (the throttle itself). The most obvious thing is to refit my existing throttle body sensor (figured that out, no problem). I simply wouldn't like to dismantle half of my injection system, only to end up with a handfull of spare bolts and two tubes that don't fit (or something equaly entertaining).
I know that people bore the throttles in Denmark for something over 100 euro, which is a fair price for that job, but I'd have to pay at least another 100 euro to get it to Denmark and back, and I got this trottle body for 30 euro (I got a 75 cam for another 30, hehe). And the 75 throttle body can be bored to 43mm (if I find the point in doing so).

 

[arc]

all the info u could possibly need should be in this thread:

https://www.fiatforum.com/showthread.php?t=23249

 

[Rubi]

Perfect! Now to find some spare time... Thanks mates!

 

[arc]

no problem, if you have any problems i'm sure brian (DJ_Bucho) would be able to help you out.

good luck with it

 

[Rubi]

I got the flap "sharpened", I cut of the screw heads, and made incisions in the screw body, so I can use a flat head screwdriver on them. Now it's smooth, and notning sticks out of the axle. It's far from a pro job, but I'm happy with it. My TB casing is made of a single block, but it shouldn't make a big diference. I'll go to a machine shop on Monday, to get the spacer done.

 

[Rubi]

Just did it! I just installed the new TB, and it works like a charm! No high revs when idle, no "hickups", no engine failure, no fire (all the paranoid ideas I had about it ). And I did it all by myself (exept for the dumb spacer, which had to be machined to 39mm). I had to file the top end of the throttle body into a trumpet shape. I was wee bit lazy to sandpaper all the nicks out before I polished it with wet sandpaper, but it's my first TB, so I can't be blamed alot. I think I did a great job for an effective work time of one day, and a budget of 40 euro (30 for the throttle body, 5 for the machine shop, and 5 for sandpaper and stuff). This operation is very simple and efficient, and I learned alot while doing it. I think every novice tuner with a 1108cc engine should do it.

Here are some pics of what I did. I plan to install a Punto 75 cam next. Then I'll do a "chip tuning" and a dyno test.

 

[beau]

none of them links work