OK, just put on a BBK 52mm TB and my TPS sensor is our of wack on this thing. So with some research I found that I need to extend the mounting holes in the TPS so I can rotate it to achieve the correct idle voltage.

Now the questions.

1. What is the correct idle voltage for a 95 Z28 LT1?

2. Where do I test it, at the TPS connector?

 

OK, I did a lot of research on this online and came up with varying number for voltage.

.5 @ idle and 5 at WOT
.6 to .73 @ idle and less than 4.8 @ WOT
These are close, but what to go with?


Also ran across some IAC numbers but they were all over the board. What should the correct IAC count be at idle?

 

my book calls for .5 at idle and more than 4.6 at wot.

 

heres the typical values. it says .4 to .9 on the tps and 5-50 on the iac count.

 

Well I took my little auto xray out and messed with it. Got the TPS to read .54 @ idle and 4.94 @ WOT, but that didn't solve my high idle problem. But then looked at the IAC readings and the learned was at 36, but the other one was at 120. So I didn't know what to do so I was just messing around and turned the sensor 90 degrees to where the clip for the connector was facing up and it went from 120 to 0 and the learned stayed at 33-36. And that seemed to fix the problem. Now it idles around 900-950 RPM, a little higher than a normal Z's of 800. And at the .54 @ idle it's reading 0% trottle and at the 4.94 it's reading 99% idle.

Craby, you see anything wrong with this.

 

sounds like the iac is sticking or may have connection issues. whatever works, i have idle issues with the 58 mm tb i have but it seems to have learned. it may help to set the minimum idle setting. while not running you put the system into diognostic mod so the iac is closed, mine i just short the a and b terminals, then unplug the iac and set idle at about 500 rpms, shut off and plug back in.

 

does your car actually idle at 500? Any ideas if that would be the same way on my 95?

 

nope it idles between 850 and 1000 depending on how it feels. lol. still working on the system and have a bug in it somewhere. it will idle at 500, not so easy now as it did before the motor change. i think it said 450 rpms and i have been looking for it in the book but havent found it again yet. i have set both of my cars this way but with mine acting up i did set the idle stop up a bit from then so it would idle when cold. with the 52 mm tb in it i had no problem getting it low but the 58 is different and doesnt like that low idle. i couldnt keep the low idle, she is running rich and it would degrade to the point of stalling.
im pretty sure you set the early lt1s this way. once it went to electric throttle i dont know.

 

IC, well this TB has a idle screw, but the blades are already setting straight up. I don't know, when I start it it revs up to like 1500-2K and then goes down to around 1K in about 5 secs. I guess it's pretty much like what the stock TB caused, but it didn't rev that high when starting as it does now. Unless you think somethings wrong I'm just going to leave it as is.

 

when i first put the 52mm on, (used) it would not settle down and when i checked the minimum idle it was down or closed to far, reset and reset the tps, it still took a couple days for it to settle down. i think it was learning.