Ok so I searched the forum and cant seem to find any threads that describe the problem I am having with my car. any help is appreciated

The car runs and drives ok except for one little issue, the car idles great but...

if I just touch the gas and try to hold it at about 1100rpms the revs rise and fall ~ 300rpm, and it just wont hold steady

if i try to rev it just a little higher, say 1200-1300rpms it runs choppy and almost sounds like it has cams

at idle or once it hits 1500rpms and up its perfectly smooth

now this is expecially annoying since when i first start the car cold it wants to idle in that range so it runs like crap untill its warm. My first thought was MAF sensor, so I took it out and it was filthy, since Im at about 100k I figured hell why not just replace it and I bought one off the forum with 45k on it, and no change. also I did a boost leak test and there are no leaks.

also my wideband reads lean, about 15.5-16 when this is happening, not sure if this is the cause or effect

 

the problem seems to have started happening when I rebuilt the throttle body (shaft seals) and added the 10.5 hotside turbo (blew the stocker) although this is when I really noticed it so im not 100% about that

its a 03 Evo, 105k
intercooler pipes
10.5 hotside
3 inch down pipe - no cat - stock catbak (3inch cutout)
injen intake w/cone filter
jdm mr bov

I think the cars running on the stock tune right now, I took out the utec the car came with and am planning adding some mods and having it tuned very soon, but I want to make sure there are no problems with the car before I dump money into it and make more problems.

 

Just put the seals in my self and having the same issues

 

Did you set the TPS after the shaft seals install? Check with Tactrix cable and ECU Flash.

If you need help, let me know as I pass through your neck of the woods every day. I can always have my diagnostic stuff and tools on hand.

 

well the reason I dont think the problem is the tps is because it does this while the throttle is closed but the idle is higher due to warmup... my theory could be wrong though so I did adjust it.

What time you leave work 4retech? maybe on your way home you can stop by the shop... its in central valley off 32 by the commons

this things been driving me nuts... I cant wait to put my fp green and cams in but i dont want to till its fixed

 

PM me.

Anyway, during your throttle removal, Did you clean the ISC bore or valve itself? It might be going south. I might be able to get my old one for tomorrow. It works fine unless you idle in traffic for 20 minutes. Idle fluctuates between 1,500-2,500. But at least it would be a start to diag.