Engine will die, when revved at idle when AC is on (s13 w/ sr20det) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

opponheimer · 06-30-2008, 08:17 PM

s13 sr20det, fmic, stock exhaust, 255lph fuel pump, runs great, idles at 800rpm, ice cold ac.

rpms will dip and die when ac is on and car is revved.... its like the compressor is overworking the engine.. isn't there something that the computer should be doing to makeup for this??

GSXRJJordan · 06-30-2008, 08:21 PM

The computer does have a lead for A/C... I don't know what the stock programming does to compensate... let me take a look and figure out what lead it is, and where it goes.

According to the S13 SR wiring diagram I made years ago...

... it looks like it's one of the plugs that connects to the dryer? Plug 16 or 17? Those are the only things on the engine harness... the A/C compressor itself doesn't connect to the ECU, but does connect to the body harness.

So, all in all, I dunno! :/

opponheimer · 06-30-2008, 08:58 PM

I have that wire connected, otherwise the ac wouldn't work..

GSXRJJordan · 06-30-2008, 09:10 PM

Yeah, those are the only two plugs that connect engine harness to anything A/C related. You might ask Codyace, i think he's got A/C on a S13

opponheimer · 07-01-2008, 11:09 AM

I paid $85 to get an ac line made, i used stock sr compressor

japslapsilvia · 07-01-2008, 12:24 PM

ur idle speed should be higher with a/c on....if its not....check the wires for the fast idle, IIRC the valve is build in to the IACV under the intake manifold.

opponheimer · 07-01-2008, 12:28 PM

Are you talking about the botton nipple below the throttle body? Should that be routed to Intake tubing or a pressure source (charge pipes)??

japslapsilvia · 07-01-2008, 12:33 PM

no the bottom nipple is for charcol canister or boost source..... when u are looking at ur cold pipe there is a ~3/4" hose that connects to the IACV its used for maintaining idle speed...you may need to just clean it.... if the idle speed doent raise when the A/C the valve is eithor stuck or not getting a signal...

opponheimer · 07-01-2008, 12:45 PM

maybe i need to raise my idle to 1100rpm?

japslapsilvia · 07-01-2008, 12:48 PM

you should be ideling at 850~900 with out the A/c on with it on it should be at 900~1000 check the valve or the wiring

its not hard to clean search IACV its been covered several times..

06-30-2008, 08:17 PM	#1
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	Engine will die, when revved at idle when AC is on (s13 w/ sr20det) s13 sr20det, fmic, stock exhaust, 255lph fuel pump, runs great, idles at 800rpm, ice cold ac. rpms will dip and die when ac is on and car is revved.... its like the compressor is overworking the engine.. isn't there something that the computer should be doing to makeup for this??

06-30-2008, 08:21 PM	#2
GSXRJJordan Post Whore! Join Date: May 2006 Location: San Diego, CA Posts: 9,135 Trader Rating: (19) Rides Gallery: GSXRJJordan Feedback Score: 19 reviews	The computer does have a lead for A/C... I don't know what the stock programming does to compensate... let me take a look and figure out what lead it is, and where it goes. According to the S13 SR wiring diagram I made years ago... ... it looks like it's one of the plugs that connects to the dryer? Plug 16 or 17? Those are the only things on the engine harness... the A/C compressor itself doesn't connect to the ECU, but does connect to the body harness. So, all in all, I dunno! :/ __________________ Jordan Innovations has a new web site! www.JordanInnovations.com -- All your favorite FD Pro Drifters love it, trust me -- www.JordanInnovations.com

06-30-2008, 09:10 PM	#4
GSXRJJordan Post Whore! Join Date: May 2006 Location: San Diego, CA Posts: 9,135 Trader Rating: (19) Rides Gallery: GSXRJJordan Feedback Score: 19 reviews	Yeah, those are the only two plugs that connect engine harness to anything A/C related. You might ask Codyace, i think he's got A/C on a S13 __________________ Jordan Innovations has a new web site! www.JordanInnovations.com -- All your favorite FD Pro Drifters love it, trust me -- www.JordanInnovations.com

06-30-2008, 08:58 PM	#3
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	I have that wire connected, otherwise the ac wouldn't work..

07-01-2008, 11:09 AM	#5
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	I paid $85 to get an ac line made, i used stock sr compressor

07-01-2008, 12:24 PM	#6
japslapsilvia Zilvia FREAK! Join Date: Nov 2007 Location: dallas, TX Age: 41 Posts: 1,245 Trader Rating: (12) Feedback Score: 12 reviews	ur idle speed should be higher with a/c on....if its not....check the wires for the fast idle, IIRC the valve is build in to the IACV under the intake manifold.

07-01-2008, 12:28 PM	#7
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	Are you talking about the botton nipple below the throttle body? Should that be routed to Intake tubing or a pressure source (charge pipes)??

07-01-2008, 12:33 PM	#8
japslapsilvia Zilvia FREAK! Join Date: Nov 2007 Location: dallas, TX Age: 41 Posts: 1,245 Trader Rating: (12) Feedback Score: 12 reviews	no the bottom nipple is for charcol canister or boost source..... when u are looking at ur cold pipe there is a ~3/4" hose that connects to the IACV its used for maintaining idle speed...you may need to just clean it.... if the idle speed doent raise when the A/C the valve is eithor stuck or not getting a signal...

07-01-2008, 12:45 PM	#9
opponheimer Zilvia FREAK! Join Date: Apr 2007 Location: Bikini Atoll Posts: 1,267 Trader Rating: (3) Feedback Score: 3 reviews	maybe i need to raise my idle to 1100rpm?

07-01-2008, 12:48 PM	#10
japslapsilvia Zilvia FREAK! Join Date: Nov 2007 Location: dallas, TX Age: 41 Posts: 1,245 Trader Rating: (12) Feedback Score: 12 reviews	you should be ideling at 850~900 with out the A/c on with it on it should be at 900~1000 check the valve or the wiring its not hard to clean search IACV its been covered several times..