Intermittent high idle. Help! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

5t341tH · 10-31-2019, 03:06 PM

Hello all. I have a s13 Sr20det swap in my datsun. I’ve had it tuned with a powerfc. I have an issue where the idle is about 1100-1200 rpm about 80% of the time. The other times, it’s good at the 900 I’ve set it at. I’ve checked for vacuum leaks and even sprayed the vacuum areas to see if any changes. Anything that y’all recommend for me to test? Besides that, the engine pulls strong and boosts to 16 psi without issue. Thanks in advanced

Pic for attention

S14rebuild · 10-31-2019, 08:07 PM

Probly iacv acting up/sticking.

Remove it and clean it, or delete it and tune with power fc with throttle plate cracked open

5t341tH · 11-02-2019, 04:39 PM

I thought when the iacv is bad it causes low idle?

S14rebuild · 11-02-2019, 05:02 PM

It could be opening like idle jump for ac on or powersteering adjust

5t341tH · 11-11-2019, 08:10 PM

took my iacv valve off and checked it out. it was pretty clean but i cleaned it some more. still have a high idle. anything else to check?

5t341tH · 11-14-2019, 06:54 PM

So I redid the tps setting again. On the powerfc, my tps reads 0.41 but shows 0.46 when I do it with my multimeter. I get a max of 4v at wot and at closed it’s 0.46. I took apart my intake manifold to find any potential leaks and also redid all my intercooler piping. I don’t believe it’s a vacuum leak as those should lower my idle and not raise it. I played with the throttle body screw and set it at the minimum opening. What I do notice though is my ignition timing would be jumping around while my idle is high. It would go from 0-14 and jump all over the place. What could be causing this? Unplugging my z32 maf kills the engine and unplugging the tps does nothing too. Unplugging the iacv has no affect either

carcrazee · 11-15-2019, 11:47 AM

ya know i think we have the same issue and ive yet to figure this out either..., every sensor on my sr was brand new oem except for the iacv... my car has been like this for almost 4 years now lol...runs just fine though

10-31-2019, 03:06 PM	#1
5t341tH Post Whore! Join Date: Jun 2006 Location: socal (Huntington Beach) Age: 35 Posts: 2,787 Trader Rating: (14) Feedback Score: 14 reviews	Intermittent high idle. Help! Hello all. I have a s13 Sr20det swap in my datsun. I’ve had it tuned with a powerfc. I have an issue where the idle is about 1100-1200 rpm about 80% of the time. The other times, it’s good at the 900 I’ve set it at. I’ve checked for vacuum leaks and even sprayed the vacuum areas to see if any changes. Anything that y’all recommend for me to test? Besides that, the engine pulls strong and boosts to 16 psi without issue. Thanks in advanced Pic for attention __________________ lexus baby

11-02-2019, 04:39 PM	#3
5t341tH Post Whore! Join Date: Jun 2006 Location: socal (Huntington Beach) Age: 35 Posts: 2,787 Trader Rating: (14) Feedback Score: 14 reviews	I thought when the iacv is bad it causes low idle? __________________ lexus baby

11-11-2019, 08:10 PM	#5
5t341tH Post Whore! Join Date: Jun 2006 Location: socal (Huntington Beach) Age: 35 Posts: 2,787 Trader Rating: (14) Feedback Score: 14 reviews	took my iacv valve off and checked it out. it was pretty clean but i cleaned it some more. still have a high idle. anything else to check? __________________ lexus baby

11-14-2019, 06:54 PM	#6
5t341tH Post Whore! Join Date: Jun 2006 Location: socal (Huntington Beach) Age: 35 Posts: 2,787 Trader Rating: (14) Feedback Score: 14 reviews	So I redid the tps setting again. On the powerfc, my tps reads 0.41 but shows 0.46 when I do it with my multimeter. I get a max of 4v at wot and at closed it’s 0.46. I took apart my intake manifold to find any potential leaks and also redid all my intercooler piping. I don’t believe it’s a vacuum leak as those should lower my idle and not raise it. I played with the throttle body screw and set it at the minimum opening. What I do notice though is my ignition timing would be jumping around while my idle is high. It would go from 0-14 and jump all over the place. What could be causing this? Unplugging my z32 maf kills the engine and unplugging the tps does nothing too. Unplugging the iacv has no affect either __________________ lexus baby

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

10-31-2019, 08:07 PM	#2
S14rebuild BANNED Join Date: May 2019 Location: Florida-FAIL Posts: 2,495 Trader Rating: (8) Feedback Score: 8 reviews	Probly iacv acting up/sticking. Remove it and clean it, or delete it and tune with power fc with throttle plate cracked open

11-02-2019, 05:02 PM	#4
S14rebuild BANNED Join Date: May 2019 Location: Florida-FAIL Posts: 2,495 Trader Rating: (8) Feedback Score: 8 reviews	It could be opening like idle jump for ac on or powersteering adjust

11-15-2019, 11:47 AM	#7
carcrazee Zilvia Member Join Date: Jan 2012 Location: failorida Posts: 236 Trader Rating: (1) Feedback Score: 1 reviews	ya know i think we have the same issue and ive yet to figure this out either..., every sensor on my sr was brand new oem except for the iacv... my car has been like this for almost 4 years now lol...runs just fine though