I installed a Edelbrock 52mm TB with my new 383 setup (daily driver) and am still trying to resolve a few pesky drivability issues. There's one curious thing I noticed and I am wondering what you guys think about it. Let me preface by saying that I have an annoying little hesitation every time I put it in or out of gear. I suspect it to be IAC related, but can't be sure. I also have the infamous "whistling sound" that others have mentioned with their aftermarket TB's. It sounds like the sound air would make when it's being forced through a small opening, such as the IAC opening on the TB. Anyway, the curious thing is that if I am driving down the road and put my car in neutral as I'm rolling along, the RPM stays high....never drops down to the level it should be in neutral UNTIL I come to a stop. Seems to be that it should drop down to the normal neutral idle RPM regardless of whether I'm going 45 mph or at a standstill. Does anybody have any ideas of why this is the case?

Thanks in advance!

Robert

 

If it makes you feel any better, my 95 T/A M6 has been doing that since day one when I bought it brand new. My guess is that the vehicle speed sensor is telling the computer something when the car is moving, and something different when it is stopped. I found it strange also. I'm sure someone can tell you better than me though.

 

Its part of the normal programming. As long as the vehicle speed is not "0", the idle RPM is elevated.

 

Pretty common with the Lt1's from what I've heard. If Im rolling down the road and push in on the clutch, the revs will come down to 1200-1300 rpms. Once I come to a stop they drop to 800 where it idles.

Brandon

 

As fred said, that is normal.

You can change the RPM via programming. You want to mess with the MPH vs IAC counts table.

 

Thanks to everyone for the prompt replies. I'm glad to know this is something normal

Robert