Hello to all! I'm the original owner of a red 85 RX-7 GS with the 12A engine and 5 speed.

Recently replaced the coasting valve (thanks to mazdatrix.com for the tutorial). I found removing the rat's nest helped considerably in accessing the carb bolts. Doing this job required a considerable amount of patience especially dealing with all the vacuum lines of said rat's nest.
After reassembly I find I now cannot adjust the throttle sensor so that current flows simultaneously to both test meters. Don't know how critical this is since the shutter valve now operates properly but am concerned. I even replaced the throttle sensor with another but no dice. Readjusted the mixture and throttle screws, rechecked all vacuum connections, valves, gadgets and solenoids associated with the emission system to no avail. Any ideas on this would be appreciated immensely.

 

Well, if it were me, I'd replace the rat's nest. Hope you saved that stuff, that's what makes a Nikki happy.

 

I checked said rats nest and all orifices are clear with no damage or leaks. All vacuum lines were replaced. I wonder if I disturbed or damaged a critical part when lifting the carb to replace the coasting valve? I inspected all around the area I was working in and found nothing amiss. I will continue checking all other emissions related components.
I cringe every two years when the CA emissions check is due. For the first 20 or so years the car passed no problem then the cats started going out, which I had replaced a few years ago. Recently the CO ( carbon monoxide) levels were too high when tested and was told the engine was running too rich. I found that the coasting valve wasn't operating correctly so I replaced it. This time I passed emissions but barely on the CO, something else is going on in the system that needs addressing but what. I'm good for another two years but will probably be sweating it again come test time.

 

Do you have the manual? What you need may be found here.
http://wright-here.net/files/manuals...ssions_12A.pdf

 

Thank you for the info but I already have the factory manual. I'm now methodically and tediously going through all the emissions components until I find the 'smoking gun'. So far, nada!

 

Still checking but to no avail. Since the throttle sensor can't be properly adjusted, knowing how it operates and how it sends and receives info would be helpful. Perhaps the computer or some component is faulty, very perplexing. Any ideas on what may be affecting this problem and course of action I should take would be appreciated.

 

Maybe a new one. The part listed at rockauto was $190.00. Available ebay $162.00. Wish I could help more. The emissions thing is painful. Good luck.

 

Still checking the emissions system out but to no avail...except when I let out the throttle sensor screw all the way I can synchronize my test meters but the engine shakes badly upon deceleration. I must turn in the throttle sensor screw until I cannot synchronize the test meters then it decelerates more or less smoothly. I might just give up on this as I'm not making any headway. What are the ramifications of not having the sensor adjusted properly?

 

I might just undo all the work I've done installing the coasting shutter valve, including the 'rats nest', and see if something went out of place or broke a wire when I first did the job. I wish I didn't have to deal with these emission devices, a hassle to test everything.

 

Hi to All!
I went over my work, removed everything I did and inspected all the emission parts on the carb and vacuum hoses. Everything seems to be in order. After cleaning the carb as best as I could including where it mates to the intake manifold, I carefully assembled everything then attempted start up. It fired up immediately and ran very smoothly. When it got to proper operating temperature, I adjusted the mixture and throttle screws to spec then went to the throttle sensor. After all that work of removing everything then putting it all back together I still couldn't adjust the sensor so both meters (or lights) hooked up to the test connector would go off simultaneously. Don't know what to do now. What component would feed info to the TP sensor, could that component be faulty? Perhaps it's the computer that's haywire. Very frustrating! Any help would be most valued.

 

I've been following your story, sorry I can't help. You run and idle well, it's just the TPS not acting right? What a pain. The ecu is under the passengers feet.

 

Hello Cookboy and thank you for showing interest in my dilemma. The next phase of this process is to focus on the ignition system - checking the distributor, igniters, pickup and ignition coils. Then off to the ecu! Perhaps my findings will help others with a similar problem.

 

Correct me if I'm wrong, it sounds as if your car is running well, you're just not getting the TPS testing within spec. Is that it? I can dig through some stuff and find the one from my 125000 mi car. Yours at no charge if you want it and I can find it.

 

Strong ignition is key to complete combustion. The TPS is available I think from rockauto.com, but ain't cheap. I think I have mine in a box in the shed. If I can find it it's yours NC.
Edit: I didn't think the above post posted. Hence the second.

 

Thank you for the offer, most appreciated! I've replaced the TPS with another used one but didn't achieve the results I hoped for. Perhaps that one was on the outs too. Yes, if you can locate yours, I'd like to give it a go. My email is booboobear-1@hotmail.com, there I can give you my physical address for mailing but I'd like to also compensate you for shipping and something for the TPS through PayPal. Thank you much again for the offer.

 

Thank you Andrew for the emission parts. The issue of not being able to adjust the tps using two voltmeters still exists. I've checked as much as I can but cannot account for the non-synchronization of the tps. I pulled the carb and inspected everything, all seems to be in order. Nothing apparently bent or out of shape. I made an adjustment to the oil metering rod which had too much play but it made no difference with the tps. I hate to just throw parts at it but I may have to purchase a new throttle sensor, though the one I have and the spare seems to test fine, then go from there. If that doesn't do it then...

 

Maybe it's time to move to a state which isn't so picky. I've removed all that stuff from each of the 4 12a's I've had since 1988, and have no other advice. Maybe find an expert? There oughta be at least one in CA.

 

I'd love to remove all the emissions components, it'd make life so much easier. Unfortunately CA requires biennial testing and there's a bill waiting to be passed that requires vehicles 15 years or older to have a yearly inspection. It's the pits! Yes, it may be time to consider a specialist though mechanics in my area are reluctant to work on a RX-7 due to unfamiliarity.

 

Was able to synchronize the tps by backing the adjustment screw all the way but it resulted in the engine shaking considerably upon deceleration. Something is amiss!

 

If you post this in the 1st gen section you'll reach a wider and more knowledgeable audience. Somebody knows the answer.