OriGiNaL TyPe R

iTrader: (2)

Okay first before the flagging and bashing starts. I do look up plently of information and the 2nd gen search and destroy(the problem on hand) is never easy, so many threads so little time.

Okay this is it. I have done a 87TII swap. complete 87TII motor,ecu, and tranny. the car is running starts fine, good compression however the idle is rough, she bounces between 1100 to 1800. i have checked for vac leaks nothing yet(by way of carb cleaner)will check again though. TPS set, will get some PVC to remove my TMIC to set the idle and fast idle, then rest the TPS.

my question is on the left hand harness i created from scratch(1x gangplug) i dont have the port air solenoid valve (1S), water nor the air bypass solenoid valve(1c) connected to anything. do i have to have them plugged into anything? would it help my idle issue?

those part seem to have a connecting coupler already.

gsl-se addict

iTrader: (3)

port air is emissions related. It is OFF anyway once the mileage switch in the 2nd gen cluster would exceed 20,000 miles..so it would generally be inactive in a 2nd gen car. No impact to idle.

The air bypass solenoid valve seems to only be active during cold conditions. It probably wouldn't cause your problem.

It acts like a misadjusted TPS, but we set the TPS and it still does it. It even does it with the BAC disconnected, so it is not caused by the BAC opening and closing.

OriGiNaL TyPe R

iTrader: (2)

Good Day all,

I have tested the resistance on my bac,cas,port air sol,water thermo, air thermo, tps and variable resistor(round thing that adjust rich/lean). i have removed the TMIC sprayed everywhere for vaccum leaks nothing found and my boost gauge is showing -5@1100 then when it bounces to 1800 its between -8 to -10psi. from what i was told that is normal.

I have removed and reinstalled the cas to ensure correct timing good fuel pressure and everything. funny thing is when i unplug the bac nothing changes. from what i have read there should have been a change, but the bac had good resistance.

i read on here that the BAC connection inside the ecu could be bad thus not signaling the BAC. anyone had that issue here.?

OriGiNaL TyPe R

iTrader: (2)

Hey Kent,

I got some PVC and removed the TMIC, there doesnt seem to be a vac leak. i got the temp gauge, oil pressure gauge on point, shes not getting hot, checked the compression 85 front and back . i am at a loss. i am still trying to find out exactly what the Intial coupler set does.

gsl-se addict

iTrader: (3)

I found that the initial set coupler looks like it is just used for checking the knock sensor. Don't know if it is used for anything else.

When you start the car, try pressing the throttle to the floor 1 time before starting. That will engage the fast idle cam. You should fast idle (1500 rpm or so) until the car is warm. Then it should drop to about 800 rpm if everything was working correctly.


For the BAC system, the FSM says it uses the following inputs for it:
- CAS
- TPS
- Water Thermo sensor (back or water pump)
- water temp switch (maybe the one in the water pump outlet?..I'll have to check)
- intake air temp switch (this may be an error. I know of 2 intake air sensors, but not an intake air temp switch)
- power from ignition switch
- signal from A/C if A/C is on

Maybe something is disconnected causing the BAC system not to function?? Perhaps it would be worth warming the car up and then checking all of the ECU voltages again. Most of them looked good when we checked them, but maybe we overlooked something. This is the easiest way to tell if something is unplugged.

gsl-se addict

iTrader: (3)

Sounds like these guys are having the same problem:

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/bouncing-idle-bad-gas-mileage-833519/

This also might be helpful, but doesn't cover your problem:

http://www.teamfc3s.org/info/articles/idle.html

OriGiNaL TyPe R

iTrader: (2)

i will try this one >https://www.rx7club.com/showthread.php?t=833519

this one i have tried to the best of my abilities>http://www.teamfc3s.org/info/articles/idle.html[/QUOTE]

i sure hope its a hose. but it doesnt seem like it is.two cans of carb cleaner has lead me to believe that

OriGiNaL TyPe R

iTrader: (2)

I was looking over my thread(s) and decided to update the ones that have no end result..with the end result.

the final fix on the was replacing my Primary injectors.

mazdaverx713b

iTrader: (91)

good to know and thanks for updating. i edited your thread title so that when other people are searching for help they might be able to come across this thread eaiser and use it for reference.

OriGiNaL TyPe R

iTrader: (2)

thanks man...was just on here and wanted to finalize my threads as i dont like to search for info and read threads without a final result of the original posting.