Mouse2k4

1987 TurboII rx7
Mild streetport
rtek 1.7

My car seems to have a slight hiccup or choke while holding a speed. Only way to avoid it is to constantly accelerate or decelerate I cant maintain it. Its not very noticeable but its a slight cause for alarm.

Is this a TPS issue or a coil issue maybe idk.

Hazard15301

iTrader: (5)

Definitely sounds like maybe a flat/dead spot in the tps.

satch

iTrader: (1)

Does it occur at a particular speed only?

Mouse2k4

nah just when I hold any speed.

Mouse2k4

bermp

satch

iTrader: (1)

Have you tried unplugging the TPS for a test drive?

Mouse2k4

No I havent but what should I expect?

satch

iTrader: (1)

Maybe the hiccups would not occur.

Mouse2k4

Ill give it a shot and return the results.

satch

iTrader: (1)

And make sure the Boost Sensor is working properly and that the vacuum hose is hooked up properly.

Mouse2k4

If the boost guage doesnt seem to work properly would that mean that the sensor is probably bad?

Boost guage seems to work when it wants to.

Mouse2k4

Tried driving with the TPS disconnected and the problem persists.

AGreen

iTrader: (11)

I used to call this symptom "fish bites". Usually occurs when cruising or lightly accelerating. Not saying this is the exact cause, but most times it's solved by plugs and wires.

satch

iTrader: (1)

Did this problem just appear out of nowhere? And did it occur after doing some work on the car?

Silverfc88

iTrader: (7)

Maybe check the o2 sensor?

monty11ez

Have you looked at your motor mounts? If they are bad it can cause a bucking like feeling when transitioning from accelerating to decelerating.

Mouse2k4

This problem has existed since I bought the car. I could try changing the O2 sensor out. The motor mounts look and seem alright except I get some clutch chatter coming out of first gear. Maybe solid mounts could be an idea.

satch

iTrader: (1)

Read post #7 to check the Oxygen Sensor.

https://www.rx7club.com/2nd-generati...-gauge-497578/

lastphaseofthis

iTrader: (8)

have had this issue before, and helped a few others resolve theirs'. for me a new O2 sensor. some other things are exhaust leaks before the O2 sensor( cracked manifold ) bad gasket.

my understanding of the issue is the car doesn't run rich enough during closed loop( O2 sensor monitored fuel control) and falls on its face until you give it throttle pulling out of closed loop.
when you return to cruise does it seem to run perfect for 4 or 5 seconds and then fall on its face again? replace O2 first if you know you have no exhaust leaks

TheIMightyHutch

I had the same problem in my NA, it was the TPS for me, re adjusted it and now it drives smooth as can be again.

Mouse2k4

See now just an object of interest but my BAC sensor pretty much isnt connected and is pretty much a block off plate because its all kinda sealed up.

Mouse2k4

Okay so now just in a practice of testing a TPS I used this spare one so I wouldnt have to pull off the intercooler just yet. But in this video it shows a clean sweep from 5.99 thousand all the way down to 122.7 However, when manipulated quickly it would O.L which if im not mistaken means that it has a blow open meaning that this TPS is bad.

Can I get a confirmation based on this video.
<iframe src="https://www.facebook.com/video/embed?video_id=582174801818030" width="1280" height="720" frameborder="0"></iframe>

satch

iTrader: (1)

For testing dead spots when using a multimeter you would be better served if using an analog/needle meter and not a digital version.

Mouse2k4

I just spent a good hour at the car trying to figure out how to get my current one at 1k ohms but the lowest I can get it is 1.6k ohms. Also mine doesnt look like the one in the picture(FC3S Pro v2.0:&nbsp TPS adjustment for 1986-1988 RX-7 Turbo II models) mine is more horizontal and the adj screw is upside down. does this mean its on wrong or just a different series or something?

Mouse2k4

I guess I could make this work though.. Loosen up the throttle cable should let me hit that 1k but idk how it will effect the idle because it seems like it would bog in some situations.