Ok so ive got this lovely '90 N/A FC only about 100k on it. I recently came to discover that the reason i had to drive with my foot on the gas was because the hose leading from my intake pipe to the BAC valve was not connected. I had been attempting to fix the idle via TPS adjustment and the air adjust screw but have never checked that side (also may be important that i have never grounded the test coupler...) so due to my previous attempts to adjust, when this hose was reconnected my idle was about 3000rpm. turning the air adjust screw all the way back in I achieved an idle of 2000rpm. (high but very nice and steady) adjusting the TPS in the same day, i got the idle to go down but when it gets below 2000 it pulses rythmically about 1.5 times per second and between 1100 and about 1700. again it may be of some importance that i have never grounded the test coupler and the ECU may be compensating but I don't know what to make of the eerily steady pulsing idle, and why when i adjust the TPS screw so the idle gets up to 2000 the pulsing just stops.

 

The pulsing indicates the TPS is bad or mis-adjusted. TPS set correctly will not effect idle.

 

The TPS was very recently replaced with a new oem unit. do you think that grounding the test connector with the air adjust screw high and lowering it when its grounded would work? i mean it idles wonderfully smooth as of right now but its at about 2krpm

 

I mean after months of driving with my heel constantly on the gas im happy it idles but i would like to be able to dial it down to at least like 1000

also, this may be unrelated but on the drivers side top of the block near the firewall there is this Y looking connector that has a hose attached to the passenger side of the split and on the drivers side there is a nipple that looks like it should have a hose on it but doesnt. does anyone know what that is and what i should do about it?

 

Sounds like there may be a vacuum leak somewhere. The following links are to the online FSMs. Download and start studying, enjoy,

http://foxed.ca/foxed/index.php?page=rx7manual

http://www.wankel.net/~krwright/cars/rx7/manuals.html

 

*bump*