RotarysNoPistons

My motor is idling at 1500 rpms and bounces just a but also when I'm on the throttle. Anyone know how I can lower the idle. (Already messed with throttle went down from 2000 to 1500 noticed my tps looks different from most rx7s) and fix the throttle bounce? Please help.

misterstyx69

iTrader: (142)

Post a pic of your TPS if you think it is different.

RotarysNoPistons

This is it.

RotarysNoPistons

It's looks alot different from tps I have seen

Rotaryhaven

iTrader: (17)

what year RX-7? looks 86ish....most of the time is because you have an intake leak...that is what causes the surges and idle to be off wack...

satch

iTrader: (1)

You have an S4 so you have an S4 TPS. If you had an S5 you would have an S5 TPS which looks different from the S4 version. After driving for at least 20 minutes turn the engine off and w/key to on measure the Green/Red wire of the TPS for DC voltage. It should read 1 volt. If it does not then adjust the screw in the spring right next to the TPS until it measures 1 volt and maybe this will help w/the surging idle. As previously noted, it could be a vacuum leak and it can also be an incorrectly set CAS.

RotarysNoPistons

Alright man I appreciate it if it doesn't read 1 volt at all the tps is bad? Could the BVAC effect idle also?

satch

iTrader: (1)

No, you would have to adjust it to 1 volt though it can be one volt, but be bad at the same time. There is an ohm method to test if it is within spec and if it is adjusted to one volt then it should top out at almost 5 volts when the piston is maxed out and the process of going from 1 volt to 5 volts should be smooth w/no bumps.

The BAC could either cause an idle which is too low or too high, but 'usually' doesn't cause an erratic idle.

RotarysNoPistons

Well it did idle at 2k before but alright ill try that out and let you guys know thanks!

satch

iTrader: (1)

Chances are the CAS is set incorrectly or the throttle cable is too tight or the BAC is stuck in the open position or the AFM flapper door is open too much or a vacuum leak.

RotarysNoPistons

Well the throttle cable actually isnt tight and I feel like the bac may be stuck or the afm. The afm is next to tps isn't it?

satch

iTrader: (1)

AFM is under the air box. You could tell if the throttle cable was wrong by pushing up on the throttle linkage at the front of the engine associated w/the TPS. If the idle speed lowers then the cable is either too tight or the throttle plates are opened too much.

satch

iTrader: (1)

And of course the Fast Idle Cam on the rear of the throttlebody could be the cause of the high idle.

RotarysNoPistons

I was looking at throttle plates and they are always open I think it's the bvac I'm pretty sure now

satch

iTrader: (1)

The primary throttle plates should barely be open if you took the intake off to look at them and I mean barely open. Did you try to press upwards on the throttle linkage as suggested while the car was idling? You need to check these things if you want to solve your problem.

RotarysNoPistons

Well I checked the plates and it's wide open I think the vacuum line to it has a leak so it's not pulling the plates to a close.

satch

iTrader: (1)

What vacuum line to the plates are you talking about? And for krikey sake will you just try pressing upward on the front throttle linkage to see if they close or not. I mean how hard could something so easy be? W/the engine off and the intake removed from the throttlebody the primary plates should be almost completely closed. If they are not it has nothing to do w/a vacuum hose. And are you sure you are looking at the primary plates and not one of the set of secondary plates?

And if you removed the air hose to the BAC and plugged both ends and the car still idled high then it is not a function of the BAC.