88 SE

So everything seems hooked up ok , but I noticed I found this sensor that is still plugged in, but not stuck into the radiator / engine.

Come to find out , the car has an S5 radiator in it. Damndest thing. The sensor in question is resting on the drivers side fender well right now but it obviously looks like it goes somewhere , havent had a chance to fumble with it yet

The car is running pig rich and emissions are due soon so im going through trying to figure out what the devil is going on. The car smells like a rolling gas station, im assuming this has something to do with it.

Next on the list is exhaust leaks and O2 sensor, sigh, it never ends

I'm also assuming this is the proper radiator for the car since it's an auto, i guess ill have to look further into it and make sure it is.

Any idears?

NZConvertible

i assume you're talking about the coolant temp switch in the bottom left side of the S$ radiator. This switch is for emissions only, and removing it or unplugging it will but affect the normal running of the engine. It certainly won't cause the symptoms you describle. Neither will the O2 sensor or exhaust leaks.

Grab the FSM and perform the checks on the more important sensors, namely the AFM and coolant temp sensor on the back of the water pump.

88 SE

Guess I'll have to dig out the multimeter, after a bit of reading I've come to see a few things

Mainly the car stinks like a rolling gas station only at idle .. at speed seems to get *ok* gas mileage so it probably isnt related to the O2 sensor system. <sigh>

I do have to pass emission very soon though...

I guess I'll just jumper the wires for the sensor since it doesn't get cooler than 90F at night here right now anyway...

Never had to delve this deeply into an FC before .. im assuming theres room to jam a probe from a multimeter into the harness connector at the CPU? (since i don't have that creepy looking tool the FSM speaks of)

NZConvertible

You mean the ECU, not the CPU. Yes, it's easy to back-probe the ECU plugs to read their voltages. In fact that's exactly what the S5 FSM tells you to do. The creepy looking tool in the S4 FSM is nothing but a glorified voltmeter.

HAILERS

This brings up Factory service bulletin no. 047/88 titled Water Temp Switch - Rought Idle. The bulletin tells the mechanic to check the wiring of the switch and to check the voltage at the ECU for the right voltage.

Now either THEY know better than us OR there's something we don't know. I more or less dismiss that bulletin given that my wiring and voltage are good anyway. Just a curiosity.

88 SE

Definetley worth looking at, car has such randomly "ghetto rigged" things on it and with the heat here i guess it's something worth looking at too with how brittle the wires are. I'm going to die of heat stroke getting this thing to pass a sniffer test

HAILERS

A foul smelling exaust can mean the catalytic converter is kaput AND/OR the ACV/AipPump are not working in harmony.

I'd spend a day looking to see if the ACV is working properly. At IDLE there should be only a whisp of air being dumped out the relief port on the acv. That's the large hose on the bottom of the acv.

If there is a whisp only, then rev the engine to just over 3800rpm and then there should be a LARGE amount of air being relieved out the relief port.

That's not an official test but should give you a clue if its working right or not.

At idle MOST of the air from the airpump is being sent to two holes in the exaust ports of each rotor to mix with the exaust gas prior to it getting to the catalytic converter. IF the air is being dumped overboard at the acv's relief nipple, then obviously it isn't getting to where it is supposed to go and the acv is NOT functioning right and you'll fail emissions testing.

88 SE

Ah, thanks for shedding some new light on that.

I noticed while I was under there the car has an aftermarket filter but the air pump itself is drawing air straight out of the engine bay. Maybe the stupid thing has gone bad. I'll check for ACV operation for sure though.

oh man would it be nice to be able to come to work not smelling like RX7 exhaust.

I have the cat suspected in the back of my mind but the exhaust smells like unburnt fuel more than anything.

I'm going to be ordering the replacement system from discount-converter.com and just get all new cats but I don't want to risk burning up a brand new one until I can figure out the stinky exhaust.

HAILERS

With the car fully warmed up (hot) do this: just above the acv there are two vacuum hose about a half inch apart. With the car idling, pull one hose off at a time and see if there is a suction on each HOSE. There should be a vacuum on each HOSE. As in HOSE and not metal NIPPLE.

88 SE

Did a few of the tests and narrowed the problem down to the blue solenoid being bad, and now...

Both of those vacuum lines have very strong vacuum. The port is dumping barely a huff of air at idle, but more air is dumped as RPM's rise, by 2000 rpm it feels like a nice bit of wind being dumped .

should it be dumping out any at all before 3800 RPM?

Found a local source for the water thermo sensor for 16 bucks so I'll be putting that on tomorrow as well.