juan0

i just fired up my project S4 TII and the engine idles fine, only thing is i have the usual bouncy idle around 1500 rmps, and one problem i see is that on the throtle body the car came with, there's only the set of butterfly valves that go in the very back of the TB. i also tryed adjusting the screw that's on the BAC valve and the idle doesn't go up or down, and i can't get the idle to go down to at least 900, it's always bouncing at 1500,i disconnected the TPS to see if the bouncy idle ould go away, and it somewhat did, it would bounce every 5 secs... and i still had high idle, i'm not running any emissions at all, and i'm pretty sure my vacuum lines are routed correctly and all the vacuum caps are also correctly, i have not adjusted timing yet because i've not been able to bring down the idle, i have the CAS right in the center. Any ideas?

juan0

mmmm?

fear740

Adjusting the TPS is a simple maintenance item that should be preformed at any oil change. The benefits include better gas mileage, better performance and a smoother idle. Adjustment only takes a few minutes if you follow the directions below.

What You Need
· Ohmmeter
· Flathead Screwdriver
· Half an hour

How To Adjust
· Warm the car completely by driving for 20 minutes
· If your car is a turbo, remove the intercooler. Loosen the hose clamps on the inlet and outlet, remove the vacuum line, and then remove the four bolts (I believe 11 or 12MM). Lift off the cooler. Do this quickly so the car does not cool.
· Unplug the TPS. On 89+ cars, you want to unplug the connector leading from the lower TPS.
· Hold the TPS connector so the hump points up. Connect your meter between top connection and rightmost connection.
· Adjust the stop screw until the meter reads 1K (1000 Ohms)
· Plug the TPS back in
· If necessary, reinstall the intercooler. Don’t overtighten the hose clamps
· Drive the car for a few minutes, then repeat the procedure

smokimon001

i have 86 GXL N/A, having exactly same problem as you do, not running emission either. i had cleaned bypass air control valve, adjust TPS, changed whole throttle body, adjust any possible set screw(the one on top of throttlebody, set screw on bypass air control valve)still didnt work, some said i need a APEXI AVC-R.

the only one time that give me a steady approx 1000rmp idle was, when i clamp the hose that split from the intake to bypass air control valve to minimized the air flow.

let me know when you got urs fixed.

chino_rx3

iTrader: (3)

Well I just got a 87 rx7 and it idles at 1500 rpms as well , I mess with the set screw in top closed it completly and it went down a bit but it should not do this right .? Not sure what it can be ? hope I can find some answers with yours,,

arghx

iTrader: (3)

Follow the factory recommended procedure in the fuel and emissions control section of the service manual.

smokimon001

http://www.flickr.com/photos/23732694@N03/4561706961/

try to unplug that, and clamp on the air hose(with a blue paper tape on it). i did that, idle went down. not sure if this is proper.

smokimon001

i am running my car with that unpluged, idle around 750 steady, everythign seems fine. if the gas milege is reasonable, i am leaving it the way it is now.