i just installed my new homemade intake manifold (pics later) and throttle body that i bored out from 58mm to 63.5mm and i have an idle problem. it used to idle at about 1100rpm, now it is 2200rpm even after warming up! there is no vac leak, infact i am getting 22 in/hg of vac at idle, whereas with the stock setup i was getting 21 in/hg of vac at idle. i checked the tps and it is set up properly reading .4ohms at closed and 5.0 at wot. i am pretty sure that it is a tb problem because i tried to install the overbored tb on the stock im before and had the same problem. my fuel pressure is set correctly and my oil pressure is now always around 60psi because of the high idle. i tried adjusting the idle adjustment screw all the way in and it doesn't seem to make a difference. why would i get such a high idle without a vac leak somewhere? any help would be greatly appreciated.

 

Don't take offence, but I ask this only because I don't know what you know about machining etc. You did make a larger butterfly to fit the newly bored throttlebody right? Might as well get the simple questions out of the way first :P

 

yes. if it didn't fit properly i probably wouldn't draw more vacuum than when i had the original tb on right?

 

here are some pics of my homemade im.

http://www.villagephotos.com/pubbrow...elected=823546

 

hmm...thats a tasty IM you fix the problem yet?

 

maybe u got a vacuam leak somewhere. the welds dont loook lik they hold up all that great. heh the whole peice look nice but the welds look like ---- man

 

they look a little thick, but I don't know about "looking like ----" that's a little harsh

 

Have you bored a throttle before. What did you use to make the new plate. I'm assuming you used a lathe? i would take the throttle body off and drop some water into the base of the plate if it leaks onto the other side you have your problem.

 

They look a little thick, but not like ----. Welding aluminum takes alot of skill. I think it turned out nice. Looks like you have alot of nice tools at your dispose. And a nice welder too!

 

i am pretty sure the leak is the butterfly valve not sealing off properly. i can't see it being anything else. i've uploaded some more pics and you can see where i got a little aggressive when i was boring it out and had to fill a hole with some jb weld, hmt style! i just ran the bore again after patching it up and it looked fine!

i'd say they aren't too bad for only having had one lesson. welding aluminum is a lot different than welding steel. perhaps you could show me some of your aluminum welding, ya know, how it should look? or maybe we could do an educational trade off... you could show me how to weld properly and i could teach you how to spell.