Crazyw0lf

Hello,

Recently bought a FC GXL NA from 1987 and i got some trouble getting it to run normal.

Ill start by explaining what i did already to fix some problems and what i tried after that to fix other ones.

When i got the car the idle ran 2500-3000rpm wich after some looking around was cuased by clogged up coolant pipes going to the BAC and Waxstat. I cleaned em out gave the engine a good flush and put new coolant in the engine.
After i did this i had a engine that ran lower but erratic rpm 1000-1200rpm after looking around i noticed i had to set the TPS wich stated the waxstat had to be out to do so, wich pointed me to a broken waxstat it just doesnt move outwards when the engine heats up. So for now i have disabled the fast idle system and adjusted the TPS to 1000ohm and the idle is ok but maybe a little low? (500-700rpm).

But now the current troubles start, If i leave everything connected i get strange 4gas analyzer readings. CO 0.7 O2 +15 HC +-600 and lambda is off the charts. Wich after some reading got me looking at the air valve control, but that part is currently confusing me. If i unhook it (pipe coming from air pump) and run the car the CO goes up the roof to a 8.0-10.0. Cant you run the car like that on idle? Or does this just mean the valve is stuck open?

Looking around all i can find about testing the air controll valve is take off the intake hose and check if it sucks air when the rpm is suddenly dropped from over 3000rpm... cant say i notice it doing that and i think i can also feel a slight pressure comming out the hose when running idle but not sure.

Hope some can help on this as well i am thinking is it worth doing all this and trying to fix the injection controll systems or should i look into a Holley Carb swap? ( i always did like Carburated cars more for there rough feeling). Does anyone know what kind of emission a Holley carb has idle so i know if i can even consider it with my country's laws on emmision, they are pretty easy though think a 87 model is allowed 4.5 or 3.5 co on idle and hc isnt even looked at over here.

Well hope someone has some advice

Edit: Just remeber something else i found odd the temp gauge in the car doesnt get close to halfway and the radiator feels pretty cold. Does a rotary not heat up alot when undriven?

satch

iTrader: (1)

!/4 up the temp gauge is normal and 1/3 would be the highest it should go when running the A/C.

Crazyw0lf

ah ok thanks that clears 1 thing up already
Now on to the air valve

EDIT: Just found a "training manual" in a other post and noticed something i did find odd from the start. My FC has a 3rd exhaust pipe wich goes past the cat and muflers. Wich i think is called "relief air pipe" wich i geus i only supposed to open under decelleration... well mine is open non stop and if im not mistaken it is operated by the air controll valve? So do they tend to get stuck? Or am i looking at a broken one?

lduley

iTrader: (1)

The pipe you see is what engages the 5th/6th ports, the backpressure opens them. If you follow that pipe up, it should go directly into the air control valve IIRC, been a year since i looked at my ACV as i've taken it off

Crazyw0lf

Sorry wasnt clear enough i think, the pipe i mean isnt something like a rubber pipe or tube that goes to the engine (this is the one you mean i think?) but a metal pipe that runs allong the driver side exhaust line to the back of the car. Only NA engines have it and as far as i can tell not all country's have this exhaust pipe system?

Going to try and put vacuum on the control valve manualy to see if i can notice the valve do anything or not. Atm the vacuum hose going to the valve has no vacuum on it not sure if the standard running state should be with or without vacuum though.

misterstyx69

iTrader: (142)

Yes,
That is what my friend is speaking of.
That pipe goes operates the 5/6 ports in an S4.

Look up: split air pipe.

Crazyw0lf

Right didnt have much time, but had a look at some things

Seams this is indeed the split air pipe got confused becuase it starts in the exhaust after the manifold (was comparing the wrong exhaust system before) so is it normal this part of the system has a constant flow of exhaust gas comming out bypassing the catalist? Find that a tad odd?

I also took my air control valve off as i though it was defective, took it appart and look like everything works on the valve itself and no rubbers are torn. The air control check valve is also in order.

But one thing i really do not understand and i am not sure if this is normal and i am just looking at all the drawing i find wrong or not. On idle my air control valve is letting my air being pumped into the check valve into what looks like the intake manifold?? (going to blow some air in it tomorow with valve out to check) because i though it was to standerd blow air into the air silencer?

Since i unbelted the airpump the car is very hard to start,floods easy and doesnt run normal under 3000rpm is this normal aswell? Going to put everything back tomorow as i drained the battery a tad much trying to move it a couple of times while it would almost not start (have to hold accel pedal down)

This engine mangement is confusing the hell out of me still even after reading up on it alot, i also keep finding diffrences to my car then any manuals i find. For instance my car doesnt seem to have the Initial set coupler to adjust the idle speed/mixture as far i can find, i checked around the coils over 4 times now (i have 2 normal coils not a electronic one as i see in most pictures).