TweakGames

iTrader: (3)

Hello all. I have tuned and retuned my TPS mulitple times attempting to rid my problem, and I am about to replace my TPS unless someone can recommend me something. I REALLY didnt know I had a problem till I got into my friends rx7 and cold or not, the idle never bounced. EVER!

Well I have read to have my TPS set to 1 ohm, when the car is warm. I have that, but here is my problem.

Right when I start my car in the morning the idle will raise and hold very high, ~2500ish range, not allowing me to put my car into first. When I put the clutch it it holds at 2,500, when I let it out it drops, allowing me to quickly press the clutch in and throw it into gear.

My idle will surge (higher rpm 1500-2000) when its super cold, and 1000-1500 when I first take it for a drive and let it warm up.

If I put my clutch in at ANY time when it is surging, the surging will either stop and hold at 2,500, or the surge will jump to the higher rpm range if it I have been driving for a while.

ONLY AFTER I drive the car for a while, THEN turn it off and let it sit for a little bit (im guessing getting the TPS fully warm), THEN starting and driving again will the idle be steady at 750. (clutch in or out never surges)

After all my experiments, I feel either my TPS is shot, or I need to set my TPS when its a little colder (not fully warm after driving and letting it sit.)

What do you guys think? I don't quite understand why the rpm and surging changes RPM when I have the clutch in or out... I am really confused. Any help would be awesome!

Thanks
~Tweak

TweakGames

iTrader: (3)

I went outside, and unplugged my TPS, I guess that would tell me if its the TPS sending the wrong signal or not correct? I havn't had a chance to get my results yet though.

TweakGames

iTrader: (3)

ohhh, I just read from this site,

http://fc3spro.com/TECH/HOWTO/TPS/tps.html

that if I dont have cold start assist, that I need to mess with the throttle stop screw. Seeing how I don't think I have cold start assist (I removed the rats nest) should I look into this? I remember playing with those a long time ago with my other t2 TB, but have been scared to ever since. :P

Roen

iTrader: (2)

You don't have thermowax or fast idle cam?

If you're bucking, that's a TPS issue, but this doesn't sound like your run-of-the-mill TPS issue.

lax-rotor

iTrader: (1)

Car running the minimum should be set to 1 Volt, not Ohm.
It shouldn't hold for very long if at all beyond a few seconds. If you'd like to avoid that put the car into gear before starting it. Then start with the clutch depressed.
To me it doesn't sound like your TPS is on it's way out. But my experiences with TPS's are they get dead spots in certain locations during the throttle range. Just my two cents.

Roen

iTrader: (2)

Cars will still rev to 2500 rpm with the clutch depressed, they won't hold at 3000 rpm for 17 seconds though. It definitely sounds like the thermowax and the fast idle cam are just working the way they're supposed to, especially if the OP isn't sure if he removed his cold start assist.

Are you sure you're not talking about your sub-zero assist, which just injects coolant?

TweakGames

iTrader: (3)

I have not modified the TB, so I'm pretty sure I have the thermowax, (and the fast idle cam, but I'm not sure what it is. If its on the TB stock, than it's still there.)

Is that possibly the problem? I removed the rats nest, but did not remove the TW?


Thanks

TweakGames

iTrader: (3)

Im am SURE I removed the sub zero assist, but the cold start assist is just the thermowax? I did not remove the TW.

Roen

iTrader: (2)

Yea, that's the way the car is designed to run, so it doesn't take forever to warm up. If it acts normally as soon as the car is warm, this really shouldn't be considered a problem, unless driveability is affected.

My RX-7's have always acted this way (all 4 of them), and I just drive lightly. (Max revs 3k rpms when car is cold).

Now, I've also had the infamous TPS pulsing idle problem, more common to S5's than S4's. When you idle starts bouncing between 1500 rpm and 1000 rpm at about 0.67 Hz to 1 Hz, that's the dreaded pulsing idle. RPM range can vary. (I've seen 2k rpm to 1k rpm bounce, as well as 2k rpm to 1.5k rpm bounce).

TweakGames

iTrader: (3)

surging idle is not normal. I have had it for so long I thought it was (normal), until I got a ride in a 7 that has never been touched. And now I remember how easy it was to drive my NA right when I got it before I started tweaking things. O.o

I am going to go change my TPS to read 1 volt instead of 1 k ohm and see if that helps.

Also I am just going to drive my car a little, and then set the TPS. Instead of driving it a lot, letting it set a little bit and then set the TPS. That seems to be the only time the TPS is correct (currently), is after I drive around, get it completly warm, AND let it sit for an hour, warming up the thermalwax completely. NO amount of just driving will fix the surging problem till AFTER I get it warm and let it sit.


Anyways, off to go work on the 7, I will be back in an hour with results.

sp00led

hahahah mine idles at 4500 when its less than 40 out.

mike_merryguy

iTrader: (8)

TPS should read 1kohm black to green at idle and 5kohm + or - 1 kohm at WOT engine fully warmed up
after you adjust the TPS you need to set the initial set coupler, start the car attach a tach to coil, adjust the variable resistor located on the pass strut tower next to the pressure sensor, should have some epoxy over the screw, i don't remember what RMPS you have to adjust to but you have to adjust that resistor and the air / fuel mix screw at the top of the TB, the end result should be a stable 750 rpms when warm
mine was acting dumb before too, never had any problems with clutch in/out though
running normal if you start in neutral you will surge about 3k rmps for a few seconds, drop to 1500 and stay there until the temp reches a certain level, if you start in 1st or R you shouldn't get the 3k surge but should still idle high until your all warmed up

edit: i said all this assuming this was ur 88na in ur sig, i am not sure of the exact fix for t2 or s5, but should be similar

HAILERS

What's the idle speed when your setting the TPS? It MUST be below 1100rpm and closer to 750rpm.

Around 1100-1200 rpm the ECU advances the timing, so make sure the rpms are below 1100 rpm and preferably the stock 750rpm when setting the TPS. If it isn't, then you just wasted your time trying to set the TPS.

A properly set TPS will output one (1vdc) on the green/red wire to the ECU when the engine is fully hot.

Actually the 2500 rpm on a cold startup has zippity doh dah with the TPS setting. It's related to the water thermowax and the setting of the fast idle screw. Prior to adjusting the fast idle screw you need to check the throttle plate opening per the FSM, FUEL SECTION. It's likely someone has screwed with the fast idle screw and screwed its setting up.

Nope. Not a TPS issue at all in fact. The 2500rpm if steady, is too high for the fast idle when cold. It should be around the 1300-1500 rpm range. The higher speed is likely related to the throttle plate opening being too large i.e. not set to the FSM. You set that opening at the time you check the rigging on the water thermowax.

TweakGames

iTrader: (3)

Ok guys, I feel so stupid on this one. BUT I'm happy now

First of all, thanks VERY much for all the help. I know these "bouncing idle" threads get annoying.

Ok, so I went out for a drive, got my car warmed up, adjusted the TPS Volt wise, and got it set perfectly. Turned the car back on and it was still high RPM and bouncing.
*insert sad face*

But then I got a crazy idea to unplug the TPS like I was going to do this morning. I unplugged it and the RPM SHOT up and held steady at 2,500ish.
*insert confused face*

I was semi happy cause I didnt have any bounce any more! I was like ohhh yeah no bounce haha. But then I remembered that 2,500 idle is only for p-port and I am not even close to that. haha

I got my small screw driver to see if I could turn down the idle with the screw on top of the bac. I start to screw it in, expecting it stop any time soon, but it doesn't. 1 rotation, 2, 3, 4, 5, 0.o my idle starts to drop slowly. MY IDLE screw was all the way unscrewed!!?!11 haha I screwed it all the way in, and then back it off a hair and I had a nice steady ~850 rpm! I tilted my head back and threw my arms up, SUCCESS! All the people outside the dorm came over and they were like what happened? I said ITS ALIVE! haha

I jumped in my car and and went for a drive. WOW haha I dont even know how to drive the car so smooth any more haha. I have changed my driving style and clutch techniques to make up for this bouncing idle crap! ITS SO EASY NOW!

There is only 1 small battle, that I dont really care about. but someone might have the answer off the top of their heads. I drive, come to a stop with my clutch in, and my RPM is 1,100, I let the clutch out in Neutral and the rpm still drop to 850... Weird, but still a LOT better! I sound like a normal car now omg, so happy haha.

People used to ask me, whats wrong with your car, and I would just say, "its a rotary", but I really should have said, "its owner is stupid and left the idle screw all the way out!" haha

ok guys, well there ya go! If you have a bouncing idle, check your BAC idle screw. (I would think this would work for Turbo and NA)

LATERS!
THANKS AGAIN!!
~Tweak

Roen

iTrader: (2)

Did you plug the TPS back in????

HAILERS

Next time it's at 1100rpm, instead of putting the clutch in, open the hood and disconnect the bac's plug and see if that drops the rpms to your 850rpm. That might tell you something.

I still think the 2500rpm is caused by what I wrote earlier. I'm not talking about how you start a stock RX on a cold day and the rpms go to approx 3000rpm for about 17 seconds and then drops to approx 1500rpm and gradually falls to a normal 750 rpm idle speed, as the water temp comes up.

TweakGames

iTrader: (3)

haha yes sorry I forgot to say I DID plug it back in.

arghx

iTrader: (3)

The way I see it, you need to troubleshoot this systematically, and you also need to understand how all these systems work together. This is a T2 swap? You need to remove the TB, clean it, and set all the screws and clearances according to the FSM. Then you know for sure that it won't be a problem. Then you've got to clean your BAC and get that set right. Then you start the car up, get it to warm up, and set your TPS. With the car warmed up the thermowax (if properly set) should retract and the fast idle cam will not be holding your throttle plates open. Then if your TPS is out of spec then replace it.

Remember that during a cold start, the thermowax/fast idle cam physically opens the throttle plates. The BAC is open to allow extra air in, while the AWS allows in extra air for 30 seconds or whatever. After the AWS stops, the thermowax slowly melts and the fast idle cam closes the throttle plates down to 750rpm. The BAC valve, if adjusted correctly, just lets a little extra air in when the engine is under load. If you understand how the systems work together it's easier to troubleshoot. This information is available in the training manual that's floating around.

The throttlebody has multiple adjustment screws on it. If everything isn't set correctly on the TB, cold start, idle, and driveability will be noticably affected.

TweakGames

iTrader: (3)

um ... k O.o

thanks.

turboIIrotary

iTrader: (9)

get a new tps a known good one....my car had a idle surge everytime it warmed up i adjusted it about 20 times without any sucess so i borrowed my friends tps of his car and i new his worked his car didnt surge or anything and guess what my car didnt surge anymore.

Roen

iTrader: (2)

lol, I'm loving these responses

TweakGames

iTrader: (3)

hehe they are just trying to help.