If it doesn't change position then either the thermowax is broken or the coolant that supplies the unit is clogged and thus not reaching the thermowax (most likely scenario). You can disconnect the coolant supply hose and if you see a bunch of residue in the hose and or thermowax then that would obviously not be good.

On an S5 if you start the car by pressing on the pedal all the way that will cause the car to go through a deflooding procedure. Your injectors could very well be clogged. Your fuel pressure might not be in spec. The cat might be clogged (if the oxygen sensor is removed and the car runs better then you have some insight to whether it's clogged or not). And when fully warmed the G/R wire of the TPS needs to measure 1 volt w/key to on. And last but least, the grounds for the ECU need to be good.

 

Maybe I'm wrong, but I think a part of your problem could be an issue with the setting of the air adjust screw or variable resistor? You said you get no idle, so maybe one or both are set to a point where the idle speed is so low that the engine simply won't idle? Maybe a more experienced user can point you in the right direction to try to get these devices properly tuned if that is in fact a part of the problem you're having.

 

Could be. I have no idea what has been previously done... or what the symptoms where before the previous owner tinker'd with it.

 

Just for fun, I went ahead and checked the fuel pressure. The max pressure was about 55psi. I let it sit after that and it backed off to 50psi after 5mins. Per the FSM, the max should be 71.1-92.4psi and should hold 57psi. Is this correct? I've seen posts about 35-40 psi.... ?? This was tested at the fuel filter.

 

I left a reply about the problem u stated it was not the ecu and i don't like giving bad info HEC

Sent from my N860 using RX7Club

 

Thanks for letting me know. What did it end up being?

 

35-40psi w/the pressure measured inline w/key to on and fuel check connector. You tested it w/the gauge 'deadheaded' and not inline. The way you measured it is appreciably lower than it should. When most people measure it inline they get 90 psi.

 

So I guess a fuel pump is on my "to do" list?? Or should I go ahead and check it inline first?

 

If its not providing a proper reading deadheaded then I wouldn't think things will improve after that point. You 'might' want to change the fuel filter if you haven't already and see what difference if any it makes. And if the thermowax piston is not changing position relative to engine temp then you also need to figure what the cause is.

 

Guess that's the next order of business. Thanks for the input.

 

New fuel pump and filter today.... not much change. BUT, while standing on my head with a mirror and flashlight looking at the thermowax.... I noticed the cruise control cable was not on the throttle body. I hooked it back up... and now it starts a little better and idles about 1500.... never changes though... cold or warm 1500. But things are looking up

 

Have you tried adjusting the throttle cable at all. If it's too tight it will open up the primary throttle plate more than required and lead to a higher idle speed.And w/respect to the Thermowax you can affect perhaps a positive change by doing one of two things. You can located the upside down screw related to the Fast Idle Cam and either place a large rubber vacuum cap on top of the screw which will force the associated linkage downward as the top of the cap will press against the Thermowax rod which then would lead to a lower idle hopefully or you can tighten the screw so it presses against the rod that is supposed to extend outwardly which will have the same affect as the rubber cap.

And look at the supplied link and see if your CAS timing matches what it's supposed to look like in post #9

https://www.rx7club.com/2nd-generati...estion-978911/

 

Progress! Now when it's idling at 1500, play with the adjustment nuts on the cruise control cable's mounting bracket. You should be able to lower the idle down to 750 rpm. If that goes well, adjust your throttle position sensor, check your timing, and check for vacuum leaks with brake clean.

 

Ya, I'm doing this as time allows... I'm really starting to feel better about it. As Satch said, I'm going to play with the fast idle and make sure she's timed right.... and adjust the cruise cable. Progress!!

 

Not much in the way of progress latley. How tight or loose should the throttle cable be? It has quite a bit of slack in it.

 

The adjustment is done with the car warm and all the thermowax stuff out of the way. Normal adjustment is about 1/8" of deflection before pulling on the exposed part of the cable moves the throttle body.

Your car sounds like the other throttle adjustments are out of whack, so start with it tight and loosen the cable until you get the car down to the idle speed you want. It's not a permanent fix, but will help with diagnosing what else is going on.

 

Got some adjustments made... starts and idles about 600-700 now... It still didn't seem to have "crisp" throttle response when reving it. I pulled the O2 sensor... it made a little difference.... I'm wondering if it has a clogged cat. It's still hard to start... gotta give it peddle...then it's ok

 

Try checking the BAC valve as it is supposed to keep the idle from falling below 750 rpm, plus it helps add additional air on start up which makes starting the car easier. W/the car idling and the A/C on pull the electrical connector from the BAC and the engine should want to stall out. This will tell you something about the operational aspect of the unit.

 

I'll try that next. Thanks for the input.

 

Ok, I may be on to something here.... while playing around, I kicked on the heater.... guess what? No heat... I'm almost 99% sure the thermostat is stuck open. My top hose is not hard.... this could be why my thermowax does nothing.... and why I'm running rich... I'm gonna put in a new one.

 

No heat could also be caused by blockage in the Heater core or a problem w/the Logicon or a problem w/the valve which opens up the access to the Heater Core.

 

This is true. I just threw the stat in 180 deg water and nothing.....

 

If you replace the thermostat you'll want to get the factory replacement as the aftermarket units are for the birds.

 

Ok, that's what I'll get. Gotta go to the Stealership?? A thermostat really can't be the root of my problems, can it??

 

Coolant flow affects the Thermowax but not much else outside of the normal things.