Irregular idle fix KADE - Page 2 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

SnakeKack · 11-26-2008, 03:53 PM

Oh by the way when I stripped the casing i noticed 2 of the ground wires were kinda chewed up looking. I fixed them though but I thought I'd post that.

Rogue240sx · 11-26-2008, 04:13 PM

Your charging system should be fine. I'd clean (Don't forget the connections. These cars are notorious for corroded connectors in the engine bay. While you're at it throw some dielectric grease into the connectors to avoid corrosion.) and check the TPS (Throttle Position Sensor) and IACV (Idle Air Control Valve) those two things were the cause of my dipping throttle. If the TPS does not send the proper signal when at rest (idle) it will not tell the ECM to activate the IACV and the throttle will dip and possibly stall the engine.

In my case liquid had seeped into the TPS causing it to give erratic readings and ultimately stalling my engine during heavy braking, especially when the headlights were on. Check the Factory Service Manual for testing procedures.

*wangan_cruiser* · 03-31-2009, 02:14 PM

Quote:

Originally Posted by SnakeKack

I don't like ressing things but I tried this and it didn't work. So far i had replaced the alternator with a Nissan Quest alternator. That made my voltage with loads on go from 13.5 to 14.5 which is nice but the idle still dips when there is too much load.

For an example after the car is fully warmed up at night I'm driving and when I come to a stop because my foot is on the brakes and the lights are lit the idle goes down. Or after I stop and let off the brakes it goes back to normal if for an example my window is down and I press the down button again the idle dips the same way.

I've checked my regular battery ground and it's good. The new alternator seems to be doing real good. And I just did the trick in this thread and I have the ground going straight to the negative term.

As far as I know the battery is ok last time I tested it with the car off it was putting out 12.65 volts. Could a bad battery still do this to a car though? I have seen batteries that seem ok but still perform like shit.

Maybe I should look into a grounding kit?

does it happens that you have a subwoofer and amp?

HS13KLS · 03-31-2009, 02:53 PM

i dont get it, so when you cut the harness apart there are 4 wires?

and to fix this all i am doing is cutting into the wires and putting an extra wire on it, and ground it to the chassis?
i guess i need more clairification

racepar1 · 04-01-2009, 11:25 AM

Quote:

Originally Posted by HS13KLS

i dont get it, so when you cut the harness apart there are 4 wires?

and to fix this all i am doing is cutting into the wires and putting an extra wire on it, and ground it to the chassis?
i guess i need more clairification

All you are doing is grounding the sensors directly. You just splice another wire into the 4-wire ground junction and ground the wire directly to either the chasis or the battery.

People need to keep in mind that there are MANY different problems that can cause idle issues and this will not fix all of them. This only works if your problem is a grounding issue, which is common. Idle issues are a serious PITA to diagnose.

miklos · 04-24-2009, 01:19 AM

My TPS has 2 wires and a shielded silver cable around them which are plugged in [not the 3 wires coming from the top of the TPS. The shield wire isn't attached to anything. Should I ground the silver shield? It doesn't go to my TPS.

Rogue240sx · 04-24-2009, 06:23 AM

No, leave the shield alone.

11-26-2008, 04:13 PM	#32
Rogue240sx Zilvia Junkie Join Date: Apr 2005 Location: Springfield, MA Age: 39 Posts: 466 Trader Rating: (9) Rides Gallery: Rogue240sx Feedback Score: 9 reviews	Your charging system should be fine. I'd clean (Don't forget the connections. These cars are notorious for corroded connectors in the engine bay. While you're at it throw some dielectric grease into the connectors to avoid corrosion.) and check the TPS (Throttle Position Sensor) and IACV (Idle Air Control Valve) those two things were the cause of my dipping throttle. If the TPS does not send the proper signal when at rest (idle) it will not tell the ECM to activate the IACV and the throttle will dip and possibly stall the engine. In my case liquid had seeped into the TPS causing it to give erratic readings and ultimately stalling my engine during heavy braking, especially when the headlights were on. Check the Factory Service Manual for testing procedures. __________________ There's not enough hours in the day.

04-24-2009, 01:19 AM	#36
miklos Zilvia Member Join Date: Sep 2006 Location: South Bay California Posts: 269 Trader Rating: (0) Feedback Score: 0 reviews	TPS Ground My TPS has 2 wires and a shielded silver cable around them which are plugged in [not the 3 wires coming from the top of the TPS. The shield wire isn't attached to anything. Should I ground the silver shield? It doesn't go to my TPS.

04-24-2009, 06:23 AM	#37
Rogue240sx Zilvia Junkie Join Date: Apr 2005 Location: Springfield, MA Age: 39 Posts: 466 Trader Rating: (9) Rides Gallery: Rogue240sx Feedback Score: 9 reviews	No, leave the shield alone. __________________ There's not enough hours in the day.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

11-26-2008, 03:53 PM	#31
SnakeKack Zilvia Junkie Join Date: Dec 2005 Location: Florida Age: 33 Posts: 306 Trader Rating: (6) Feedback Score: 6 reviews	Oh by the way when I stripped the casing i noticed 2 of the ground wires were kinda chewed up looking. I fixed them though but I thought I'd post that.

03-31-2009, 02:53 PM	#34
HS13KLS Zilvia FREAK! Join Date: Aug 2006 Location: Illinois/California Age: 32 Posts: 1,114 Trader Rating: (13) Feedback Score: 13 reviews	i dont get it, so when you cut the harness apart there are 4 wires? and to fix this all i am doing is cutting into the wires and putting an extra wire on it, and ground it to the chassis? i guess i need more clairification