Now that i have the spacer installed, when my car is idling at running temperature, when i rev it, the rpm come down to about 400, there is
a slight shudder, which you can hear at the blower, then rpm increases
to 600 and idles fine. Do i need to reset the ecu? Will i have to let
the ecu learn the new mod? It never did this before. The only other thing
i can think of is maybe i have too much vaccuum now because i took one spring out of my greddy type s bov to stop the whistle at idle. TIA

 

Yes ...try resetting the ECU . You might have a vacuum leak also

 

Yeah I was thinking vacuum leak as well...

 

If you have a vac gauge it should be in the 20 ish range...If it reads in the 10's likely a leak..and idle will be off..

 

vac on boost gauge is at 20 like you said. I dont think i have a vaccuum leak. The car idles great, its only when revved up then let off the throttle to let the rpms settle that it drops briefly to about 400 rpm, the blower shutters and makes a mechanical grating whirring noise for about 2 seconds then rpm goes up to 600ish and stays. I did disconnect the battery overnight but that didnt make a diff. I may try reinstalling the other spring back in the bov to see if that makes any diff as well. Any other imput would be appreciated.

 

belts too tight?

 

cant see it. It didnt do this before i took it off the road for the winter. Its either the plenum and ecu thing, or the bov spring. I have not changed pulleys or played with the belts.

 

To rule rule the plenum you would obviously have to go back to stock unit..Or have a dealer raise the idle.. I had to do that after several mods..

 

I spoke to tony at motordyne today regarding the warm idle issue. He asked about the throttle body and if it was unplugged which it was. He seems to think that a throttle body reset will help my problem. Stupid me also pushed the butterfly tb valve a bit before reading the instructions not to.

 

At least you did it yourself! I often try to do the job w/o reading the directions. Or in my case, when I did my motordyne spacer install, I mis-read the directions and set the tq wrench to high and broke a bolt (don't make fun, but misread ft-lbs instead of in-lbs). No big deal since it broke clean, and was able to remove the remains w/o a problem and the local hardware store had bolt I needed.

Live and learn

And no I didn't tq the others to the higher setting, once I re-read the directions, I got them all to the ~90 in-lbs.

 

My Vortech w/ Motordyne runs fine----I situations like that I use a spray sealer made I believe by Peratex on all gaskets including the solid reusable ones----Its a red spray ---Iv been using it for yrs. Chk Vaccum----OH ! I also use it on the Thottle Body Gaskets. Any place u have a potential Vac Prob

 

fwiw, the only time i ever had idle problems with a plenum mod, and i've tried quite a few, was when i forgot to put that little cap on my crawford. look for leaks.