TPS, how to: install and adjust?
 

Well, I have no idea what's wrong with it. I can jab the throttle up and down and it seems fine that way but if I slowly depress it then it bogs and stalls. I've tried the TPS all the way forward, middle and back and then in between but it still bogs. If it's rotated too much in one way the IACV buzz's. I've tried reinstalling the TPS about 5 times. Maybe it will only hold compression on idle? Maybe the rear main seal is bad and that's where the oil is comming from? Maybe that's the cause of the low compression? Maybe the apex seal springs are squished and under load they don't flex out?

THis last time I tried installing it with the TPS connector upwards and rotating down towards drivers side. I was trying to make shure that the two rotating pins would be behind the square cups of the TPS. I've tried it with the pins inside the cups but that doesn't work since moving the TPS will then move the throttle. :icon_no2:

just want to make sure that you know that there are specs that are supposed to be checked while doing that, it sounds like you are just guessing. you are supposed to check two of the wires with a voltmeter on the TPS connection when the car is at idle temp( or extend the spring to trick it.) Check the lightning in a world of thunder site and they give you a walk through.

I cant remember the specs off hand. I have them in the shop though lol. Yet i got them out of this thread...

https://www.rx7club.com/showthread.p...tle+adjustment

I can post the specs tomorrow but i figured if you in a rush you can just read through.

-Lance

Specs are in the manual. Voltage can be monitored from PFC commander. Question still remains since there is no diagram or instruction on how to mount the TPS itself. Nor does it mention the placement of the pins to the square cups.

It is a very very simple mechanical to electrical device device.
The throttle body main shaft rotates the twin variable resistors.
The two tabs on the TB shaft engage the TPS unit.

If a person can not figure how it goes together, they do not have the basic ability to be a mechanic and should not be working on the car. Mazda knows this, that is why they do not show it. It is that simple! You got it or you don't!

I can get it within closed to open specs but fully closed I don't understand and can't do. I decided to insert the TPS strait on instead of trying to rotate it on. I have a smooth idle. I started with the adjustment screw ondert he elbow all the way open (counterclockwise) and then had to close it all the way to lower the idle. I was able to get it down to 800rpm allthough I was trying for 750rpm's.

So idle is fine or acceptable as well as TPS voltage. Both the TPS and IACV are brand new. I thought the car was fixed but it still bogs or shuts off when you depress on the gas pedal.

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The TPS is always under spring tension, even at closed throttle and has to be rotated on so that the tension is there.

Did you study the complete cold start system: hot wax rod and fast idle cam?
If the engine is not fully warmed up or the fast idle cam disengaed, the throttle and TPS will not be fully closed.

I do not have a fast idle cam, double throttle nor an AWS control. Manual does not state to rotate TPS but if it is under constant tension then the pins should be on the backside of the TPS cups (not shure what they are called). I could try reinserting again with the connection upwards then rotating counter clockwise but it doesn't sink in from the upwards position.

Anyhow, manual is pointing to charge releif valve which I replaced brand new. I know it's easy to break, so i'll have to check it. It also refered to leaking primary's, FPR and TPS.

Pin your fuel pump and see what your fuel pressure is. Use a paper clip in the FP and GND in the diagnostics port on the drivers side of the engine bay. Then check your fuel pressure.

I still have a little looping idle like you and have gone through a bunch of stuff. I removed the wax rod assembly and it seemed to help a little bit more to stable the idle. It may have been seized a little bit.

^ thanks, I beleive that is so I can test fromt he engine bay instead of using the commander but my meter doesn't go below 5v. The other two I had are broken and lost.

I just received my new Sard RJ (race) FPR and was stoked because the bracket holes lined up perfect with the AWS holes. Since it's blocked off, I thought it was great. But it won't with with the ACV, D'oh! So, since with all my custom work and pissing thousands of dollars and still having to go around smog, I think it's time to ditch the shit!

I thought about removong the whole wax rod assembly and blocking it off but i'm not so comfortable not have any coolant going through the whatver even though i'm in CA.

My pump was tested on my first tune. I haven't tested it since. Fuel pressure holds steady and rises smoothly and quicky. I had it set to 36psi (stock pressure) but tried 40 to see if that would make any difference bu ti didn't. My idle is fine, it stalls when I het the gas and sounds like a three (of 4) cyclinder piston engine under load.

Might want to check out your compression. Could also be ignition related...

My compression on my new motor is bad. I tested it to about 80psi. I had almost all 7's on the last tune with one 6.7 on a Mazda tester. Went to local shop (RR&R) to restest and they got 4's and 6's. Took it to my builder and they said it was tested wrong. Went back to RR&R and they retested but charged claiming the 1st test was acurate. They got about 80-85psi on a Mazda tester from the 1700's that uses ticker tape and no ink. So, that's why I bought a piston tester and redid it myself. The only problem is it's hard to judge exactly since it bounces very quickly. So it's no less then 80psi and no more then 85psi.

i would use an actual tester and not the comander voltage. and talking to the guy at mazdatrix(forgot his name), he told me that a mechanical tester is the only way to go and not a digital voltmeter.

I can't get an appt with Mazdatrix (always told to call back in a few weeks) and would have to tow it there anyhow but John did help me to adjust it over the phone and explained the pins had to be behind the cups. Sorry, don't know what they are called. I'm not shure what mechanical tester there would be to test voltage for the TPS. Maybe you are refering to the Mazda compression tester compared to my piston compression tester?

I think your lost right now... how are you crossing tps reference and engine compression? To calibrate your tps you take a paper clip and insert it into the second wire down green/something and check the voltages at closed and open. Then do the same for the black wire at the bottom. I'll post the specs tonight when i get my book in the shop.

Though if you dont know that the metal tabs go behind the plastic on the tps sensor i dont think your going to have much luck checking for voltages...

I would talk to your engine builder though about your low compression. How many miles are on the motor?

^ I was reply to three different threads at once and they got mixed up. I am awaiting some block off plates, getting rid of air pump. I can check the voltage with the commander but only closed to open. I can't do the completely closed since I din't have the wax rod, AWS, etc. TPS is mounted with clips behind the cups, alot easier to do with the extension manifold off. Builder is allready aware of low compression, response was possibly flattened apex seal springs but no solution offered. Engine has 5k miles since latest/curent $5k rebuild.

How can you not check closed voltage without that stuff? Its going to be closed no matter what. I also have that stuff removed and can check values... oh and for what its worth dont check with the commander its been known to be off from the actual values. Boost readings have been varied and i know for a fact that tps voltage will be different.

The manual has three boxes.
the first fully closed which is the one I don't understand how to do. In a previous reply it was stated to check the wax rod and whatever for the fully closed numbers.
the closed to open box, those numbers I can get with the commander.
I forget the third box, think it's wot.

Anyhow, my first problem was narrow is listed on top in the manual but it's NTA2 on the commander and I kept thinking it was NTA1.

I know the commander will be off like .2v which shouldn't be enough of a concern if I set the voltage in the center of the range.

The reason I could not get an acurate reading and adjust my idle was becuase my cruise control was too tight and slightly holding the throttle open. It was allready adjusted to the maximum slack, so they disconected it and TPS is fine.