Problem keeping the engine speed at 2500rpm

[Martin_CRX]

Hallo everybody my name is Martin and I am from Austria

I tuned my Honda CRX with Hondata S300 V3, because of my turbo built. The engine runns quiet good during driving, just wenn you pull the throttle the engine starts to rev imedeately. To be more precise, the transition from rolling to accelerating is always hard and not smooth as with a standard car.
It is therefore very difficult to maintain a constant speed. This is also the problem I have with the exhaust gas test. When I am racing this is no problem because you are most of the time wide open anyway. I would be very grateful if someone could give me a tip where I can put this on. I already played around with trottle tip in, but the changes were minimal. The idle speed keeps the car very well at 850 rpm.

[Spunkster]

Make sure that the TPS has been calibrated properly.

[Martin_CRX]

Okay thanks I will calibrate it again tomorrow

[Martin_CRX]

I recalibrated the TPS, when i did it 3 months ago were I started my tune it was 5,3% and 98%
Now its 4,7% and 60%
But now I can hold the rpm at speed 0 at 3000rpm under it the engine reves up and down. I set the duty cycle to the 3rd position from the left.
But right know it works better, but the tune is not at the level i want to go.
So can you please give me some further tips.
I also think I have another Trottlebody than un USA my engine is called D16a8, its like the ZC in USA.

Thanks for the help!!!

[Spunkster]

It sounds like there is a problem with the sensor or the throttle body as it would be close to 0% and 100%. You should check to make sure that the sensor is installed on the throttle body correctly.

[Martin_CRX]

Yess i will check it

[Martin_CRX]

So today i built in my new TPS Sensor. Now the TPS reading is 4,66% and 99,8%. The engine is running quiet good, I also can rev the rpm to 2500 at zero speed. But the 4,66% are stil a problem and I have an oportunity wy this is so. I have a under presure cylinder at my throttle body, which keeps the trottlebody always a little bit open. If I would put this cylinder away, the throttle would close completely. I swaped from OBD0 to OBD1 and I can find no OBD1 throttle body with this cylinder in the internet. Is that the truth and should I build this thing away?

Thanks for any answering!!!

[DaX]

So today i built in my new TPS Sensor. Now the TPS reading is 4,66% and 99,8%. The engine is running quiet good, I also can rev the rpm to 2500 at zero speed. But the 4,66% are stil a problem and I have an oportunity wy this is so. I have a under presure cylinder at my throttle body, which keeps the trottlebody always a little bit open. If I would put this cylinder away, the throttle would close completely. I swaped from OBD0 to OBD1 and I can find no OBD1 throttle body with this cylinder in the internet. Is that the truth and should I build this thing away?

Thanks for any answering!!!

Which engine do you have? Are you talking about a vacuum diaphragm or "dashpot" on the throttle body that cracks the throttle plate open? I know these were present on the B18A1 (OBD0 "LS") engines in the US market...they may have been used on other engines as well. If the diaphragm inside the mechanical valve is broken, when the engine is under vacuum it will still hold the throttle plate open. I recommend removing this from the throttle body if it's still present - you don't need it. It was only intended to hold the throttle plate open a small amount during starting. Here is a picture I found on the internet of what I'm talking about:

1.png (3.43 MiB) Viewed 1340 times

[Martin_CRX]

Yess exactly!!!

I will remove it today thanks for the help!!!

My engine is a D16z5 its like the D16ZC.

[Martin_CRX]

Thanks for the help, now the engine is running perfect!!!

[DaX]

Thanks for the help, now the engine is running perfect!!!

Excellent! Glad to hear it.