edwin-82/rx7

iTrader: (1)

So last night i tore out the rats nest, made blocking plates and what not and cleaned up the engine bay. The car ran fine before i did everything, although i had to up the idle a little bit on the way home from work. Now, it is hard to start, and has a flat spot right above idle. I did some searching and looked at the accel. pump assembly while operating the throttle, and there is just a tiny tiny bit of throttle movement before the a/p kicks in. I'm fairly sure there is no vaccum leak, because there is no idle problem now. Driveability sucks now at low rpms, the car wants to stall on take off unless i let out the clutch around 1.7-2k rpms.
My mods are:
Mech. secondaries
Stripped emmissions
Racing beat streetport exhaust
I guess the best way to describe the feeling is the "flat spot" from the mech. secondaries moved down to right above idle. feels like the same thing (too much/too little fuel). Now that i think about it, would an overly rich idle setting cause this? I may have bumped the idle mix screw while fumbling around w/ vaccum caps and such, its still got the cap on it tho. Sorry for the long post, thanks in advance!

Jason

edwin-82/rx7

iTrader: (1)

*bump* anyone?

RexRX

Are all the required vacuum lines hooked up?

edwin-82/rx7

iTrader: (1)

yeah i followed the rats nest removal and double checked everything. just as a test i gave it a vaccum leak today so i could tell the difference, very rough idle! also sprayed some stuff around the plates to make sure they aren't leaking. i'm pretty sure its not a vaccum leak, i think i've ruled it out pretty well. any other suggestions? any carb gurus around??

Kentetsu

Check your ignition timing, this can make a huge difference in performance off idle. Adjust your AP so that as soon as the throttle starts to move, the AP moves with it. Make sure that your secondary plates are fully closed at idle, and not propped open due to the mechanical mod. If the plates are partially open at idle, you will be flooding (hard starts, stall off idle, etc.). Adjust the mechanical linkage so that the secondary plates are wide open at wide open throttle, but make sure that they are fully closed at idle and you should be all set. You will have to get used to not being able to floor it coming off idle though, either push the gas peddle slowly, or wait unti you are higher in the rpms before you floor it.

To check for vacuum leaks, use a lenght of hose as a stethoscope. Put one end to your ear, and move the other end around the engine and you will be surprised at what you can hear.

edwin-82/rx7

iTrader: (1)

the car was idling at around 1k, i lowered it down to 750-8 and most of the flat spot went away. i did the mech secondary mod about a year ago, so i'm used to it now and the secondary butterflies are closed at idle. the car performs great (i beat a '89 240sx with around 150hp at the crank several times tonight) but its not perfect. in fourth gear around 32-36mph is where the flat spot is consitantly noticed, but its so much better than it was. i think i'm going to have to go out and pick up a timing light soon, i've never used one before so i've got some learning to do. thanks again for the responses, any more ideas out there?