Recently finished my 383. Running LE2 heads and LE2 383 cam (sorry , no specs but it is comparable to the GM847..but with a lil more lift ). To get it to idle I had to crack the plates open. This also was advancing my timing to 36 degrees and idled at approx. 1500 rpm. My throttle plate angle was at 3% and the voltage was at 1.3 volts. I reset the throttle angle to 1% and the voltage went to 1 volt. This car barely idles with the factory specs. Infact it can (and has died) on me causing a flooding type situation. It MUST sit for approx. 20 minutes before it will run. If I crack the plates it will fire but then I get the higher idle and the lope can't be heard. If I slot the tps sensor this should allow me to crack the plates open a tad wider but still allow me to dial in my tps voltage and not advance my timing. When put back to factory specs the timing went from 36 degrees to 28 degrees. Am I correct in slotting the sensor to adjust it? Any suggestions?
I have pretty much decided on scanmaster but have yet to purchase it. I am hoping this will help me fine tune the car and get it to where it should be. I know there is more power in there, I just need to get the car running good at this point and go from there.

 

Anyone?

 

Yeah you need to slot the damn thing. Pay $300+ for a throttle body and youd think it would be a bolt-on installation. I believe the newest version or maybe Edelbrocks(essentially the same as BBk) actually have the TPS slotted out of the box.

 

My cam is big and it can hardly idle. It stalled once on me at a gas station and wouldn't restart. I had to wait 20 minutes at which time I cracked the plates open a bit more. It makes sense that I can crack the plates, slot the sensor and still keep it from advancing my timing.

 

You've definitely got something wrong here. You shouldn't need to crack the blades much at all if everything is correct. I currently have a BBK 58mm with an enlarged IAC bypass hole (there isn't one there normally on the BBK but the stocker has it), and my blades are completely closed. My cam is larger than yours @242-248. My engine idles quite happily at 850rpm with IAC counts ~55-65. The IAC bypass mod is pretty much mandatory on the BBK. BTW, my tps voltage is .65v with the blades closed. Never had to slot the tps.

 

I am interested in the by pass mod. Where do I find some info on it? Tried a search....WAY TO many threads came up mostly having nothing to do with the IAC valve at all.

 

Unfortunately I don't have any pictures to share. Take your stock throttle body and look at the iac opening from the front. It's the lower passage between the two main butterflys. You will see that there is a small hole drilled that esentially bypasses the iac circuit. Now look at the BBK, and you'll notice no hole at all. This means that with the BBK ALL idle air must go through the iac passage. The problem is that there simply isn't sufficient capacity in the iac circuit to supply the increased idle air that a cammed engine requires. What I did initially, was drill a hole in the same relative location as the stocker, the same size as the stocker. I found that this wasn't enoug as the iac counts were still high at around 90. I continued to enlarge the bypass hole until I got the iac counts where I was happy, around 50-65 warmed up. This is assuming that everything else is right, which it sounds like it may not be in your case. Never the less, you should be able to duplicate the factory sized hole to start with. Doos luck!

 

Thnaks, I'll give that a try before I start slotting the tps.