My car stumbles like a drunk - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

MacDrevi0us · 05-06-2007, 07:45 PM

92' Coupe 5spd. Only thing done to the engine is intake at this point. Car has also been seafoamed but it did not help this problem.

Ok so ive been doing a lot of reading about this because its a problem that ive had for a while, but heres the deal. Im basically have a type of idle issue. When i start up the car cold its totally fine ive NEVER had a problem with the idle on a cold start. When i notice it the most is ill be coming off the freeway and ill shift into neutral and the rpm's will drop to about 3-400 and sometimes stick and then pop back up. Its like the idle isnt catching it. Same thing happens when i start the car when its already warm. But now recently something new has started where when im sitting at a light it will bounce up and down. Ive read that this is commonly IACV which gets easily clogged with crap but im wondering if there are any other possible solutions for these symptom? Also, if someone has a picture of the location of IACV assembly that would be great. I saw it in a thread on here but cant find it anymore. Thanks

lazierhobo · 05-06-2007, 08:20 PM

IACV is a cylinder sort of thing attached to the intake, after the throttle plate. should be held on by a couple of small bolts. when you take it off, you will easily be able to see how to clean it. sorry i dont have any pictures, but if you have a FSM you will be able to see it.

benefitx · 05-06-2007, 08:24 PM

run seafoam in the IACV tube

MacDrevi0us · 05-06-2007, 10:14 PM

Aite thanks for the feedback it was very helpful. Is there only one tube on the IACV? And if not which one should I run seafoam into?

Edit: Also is this something a new fuel filter might solve or are these symptoms not typical for that?

Thanks in advance i cant wait to figure this out

beetlejuice · 05-07-2007, 01:27 PM

The IACV is on the underside of the intake manifold, near the firewall.

There is a hose going from the stock intake tube to a metal tube (underneath the upper portion of the intake manifold), which leads to the IACV. It is the larger of the two hoses connected to the intake tube, a few inches from the throttle body.

You want to spray seafoam, carb cleaner, etc in this tube while the engine is running.

If you have ABS, it will be extremely difficult to get your hands on the IACV unit itself, as the ABS control module thing in the corner of the engine bay is a monster.

Canaduh · 05-07-2007, 01:36 PM

after a 10 second search i found this...

http://www.zilvia.net/f/showthread.p...ght=idle+screw

It shows you the hose to disconnect and spray throttle body cleaner into.
Done it to my car many times, very simple.

MacDrevi0us · 05-07-2007, 04:29 PM

thanks for the info i appreciate it!

edit;;Just swapped the fuel filter with the z32 one. big difference but not solved yet so next is cleaning of the iacv.

05-06-2007, 07:45 PM	#1
MacDrevi0us Leaky Injector Join Date: Sep 2006 Location: Walnut Creek Age: 37 Posts: 84 Trader Rating: (0) Feedback Score: 0 reviews	My car stumbles like a drunk 92' Coupe 5spd. Only thing done to the engine is intake at this point. Car has also been seafoamed but it did not help this problem. Ok so ive been doing a lot of reading about this because its a problem that ive had for a while, but heres the deal. Im basically have a type of idle issue. When i start up the car cold its totally fine ive NEVER had a problem with the idle on a cold start. When i notice it the most is ill be coming off the freeway and ill shift into neutral and the rpm's will drop to about 3-400 and sometimes stick and then pop back up. Its like the idle isnt catching it. Same thing happens when i start the car when its already warm. But now recently something new has started where when im sitting at a light it will bounce up and down. Ive read that this is commonly IACV which gets easily clogged with crap but im wondering if there are any other possible solutions for these symptom? Also, if someone has a picture of the location of IACV assembly that would be great. I saw it in a thread on here but cant find it anymore. Thanks

05-06-2007, 10:14 PM	#4
MacDrevi0us Leaky Injector Join Date: Sep 2006 Location: Walnut Creek Age: 37 Posts: 84 Trader Rating: (0) Feedback Score: 0 reviews	Aite thanks for the feedback it was very helpful. Is there only one tube on the IACV? And if not which one should I run seafoam into? Edit: Also is this something a new fuel filter might solve or are these symptoms not typical for that? Thanks in advance i cant wait to figure this out Last edited by MacDrevi0us; 05-07-2007 at 01:15 AM..

05-07-2007, 01:27 PM	#5
beetlejuice Leaky Injector Join Date: Jun 2005 Location: Me? Posts: 145 Trader Rating: (0) Feedback Score: 0 reviews	The IACV is on the underside of the intake manifold, near the firewall. There is a hose going from the stock intake tube to a metal tube (underneath the upper portion of the intake manifold), which leads to the IACV. It is the larger of the two hoses connected to the intake tube, a few inches from the throttle body. You want to spray seafoam, carb cleaner, etc in this tube while the engine is running. If you have ABS, it will be extremely difficult to get your hands on the IACV unit itself, as the ABS control module thing in the corner of the engine bay is a monster. __________________ jollydwarf.com

05-07-2007, 04:29 PM	#7
MacDrevi0us Leaky Injector Join Date: Sep 2006 Location: Walnut Creek Age: 37 Posts: 84 Trader Rating: (0) Feedback Score: 0 reviews	thanks for the info i appreciate it! edit;;Just swapped the fuel filter with the z32 one. big difference but not solved yet so next is cleaning of the iacv. Last edited by MacDrevi0us; 05-08-2007 at 01:03 AM..

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05-06-2007, 08:20 PM	#2
lazierhobo Zilvia Member Join Date: Sep 2006 Location: upstate NY Posts: 228 Trader Rating: (0) Feedback Score: 0 reviews	IACV is a cylinder sort of thing attached to the intake, after the throttle plate. should be held on by a couple of small bolts. when you take it off, you will easily be able to see how to clean it. sorry i dont have any pictures, but if you have a FSM you will be able to see it.

05-06-2007, 08:24 PM	#3
benefitx Banned from the Marketplace Join Date: Oct 2006 Location: suwanee ga Posts: 670 Trader Rating: (0) Feedback Score: 0 reviews	run seafoam in the IACV tube

05-07-2007, 01:36 PM	#6
Canaduh Zilvia Member Join Date: Jan 2007 Location: Winnipeg, Canada Posts: 227 Trader Rating: (0) Feedback Score: 0 reviews	after a 10 second search i found this... http://www.zilvia.net/f/showthread.p...ght=idle+screw It shows you the hose to disconnect and spray throttle body cleaner into. Done it to my car many times, very simple.