OBD1 KA unusual idle issue and acceleration issue. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Liquidnite · 08-03-2013, 03:37 PM

I've had my automatic OBD1 S14 for about a year and a half and haven't been able to resolve these issues. After the engine warms up I have issues with a stutter in the acceleration at roughly 3700 RPM (if I slowly increase RPM it will start to stutter and drop RPM starting at 3700, increasing on the accelerator will cause the RPM to jump back up) and with the car in gear while stopped the RPM will drop to about 300. In gear with the e-brake on still sees the drop but with a lesser frequency. If I have the AC on it does still drop, but not as low. Throughout the RPM band I have the CEL light blink, and with each tap on the accelerator the CEL blinks. The CEL never stays on solid.

As I can recall I've replaced the o2 sensor, the fuel pump, the coolant temp sensor, the idle air controller, plugs, wires, cap and rotor, verified voltage is fine at closed and WOT of the TPS (thinking of rigging a wiring up to check it at 3700 RPM to see if the TPS has a dead spot), checked the brake booster and check valve for leaks, and cleaned the MAF.

Any idea's?

milto0n · 08-03-2013, 06:12 PM

Find out why your check engine light is on. Manually pull the codes by checking the ecu. Figure that out and then report back before throwing your money into anything else.

Liquidnite · 08-04-2013, 02:49 PM

Error code 34 and 105 on the original ecm. Found it was turned completely clockwise putting it into a perpetual mode 2.

Liquidnite · 08-19-2013, 09:48 PM

Video of the issue

So I was able to correct the Error 34 and it is still having the exact same issue. I've checked the Vacuum Check Valve for the brake booster and both appear to be fine with no leaks. The issue persists even with the vacuum line plugged before the Vacuum Check Valve.

08-03-2013, 03:37 PM	#1
Liquidnite Join Date: Oct 2012 Location: Pensacola, FL Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	OBD1 KA unusual idle issue and acceleration issue. I've had my automatic OBD1 S14 for about a year and a half and haven't been able to resolve these issues. After the engine warms up I have issues with a stutter in the acceleration at roughly 3700 RPM (if I slowly increase RPM it will start to stutter and drop RPM starting at 3700, increasing on the accelerator will cause the RPM to jump back up) and with the car in gear while stopped the RPM will drop to about 300. In gear with the e-brake on still sees the drop but with a lesser frequency. If I have the AC on it does still drop, but not as low. Throughout the RPM band I have the CEL light blink, and with each tap on the accelerator the CEL blinks. The CEL never stays on solid. As I can recall I've replaced the o2 sensor, the fuel pump, the coolant temp sensor, the idle air controller, plugs, wires, cap and rotor, verified voltage is fine at closed and WOT of the TPS (thinking of rigging a wiring up to check it at 3700 RPM to see if the TPS has a dead spot), checked the brake booster and check valve for leaks, and cleaned the MAF. Any idea's?

08-03-2013, 06:12 PM	#2
milto0n Zilvia Junkie Join Date: Jun 2011 Location: Mesa, AZ Posts: 422 Trader Rating: (3) Feedback Score: 3 reviews	Find out why your check engine light is on. Manually pull the codes by checking the ecu. Figure that out and then report back before throwing your money into anything else.

08-04-2013, 02:49 PM	#3
Liquidnite Join Date: Oct 2012 Location: Pensacola, FL Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	Error code 34 and 105 on the original ecm. Found it was turned completely clockwise putting it into a perpetual mode 2.

08-19-2013, 09:48 PM	#4
Liquidnite Join Date: Oct 2012 Location: Pensacola, FL Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	Video of the issue So I was able to correct the Error 34 and it is still having the exact same issue. I've checked the Vacuum Check Valve for the brake booster and both appear to be fine with no leaks. The issue persists even with the vacuum line plugged before the Vacuum Check Valve.