Cold start sr20det in ae86 issue - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

marley4us · 11-19-2013, 07:17 PM

Ok, I figured I would come here and try to get some help. I have searched and read a ton stuff, but I feel like I am at a loss.

I have a AE86 with a redtop s13 SR20det.

Under cold start, it will immediately die out. If you throttle it a bunch and keep cranking it seems to get it to idle, but rough and you have to feather the throttle until it is fully warmed up.

Once it is warmed up, the throttle will idle, but it bounces, from 2000 to about 1500. Some times it will idle ok, but mostly it does this.

It is a stock SR20det red top with B.C. 268 cams. An new external walbro 255.

Fuel pressure is around 3 bar (43.5 psi)

I am running oem 4ac fuel lines to sr20 but it does not seem to effect the fuel pressure.

My I swapped my maf, and even tried un plugging it and re plugging it in while the car was on, and it changed the idle slightly but never solved the issue.

I installed a old greddy boost gauge, and it says I have 500mm/hg or torr (10psi) vacuum, so maybe I have a boost/vacuum leak... but I am not sure....

The orange wire (cold start map) I read about but I am not sure I understand it... I am not using a SR20DET body harness, so info on that might help too

Any help idea's etc. I think this is a common SR20det problem

s13mikesr20 · 11-19-2013, 07:36 PM

i have same prob on my black top mine was tps no getting signal while cold but when it warms up works fine dafuq lol

Sileighty_85 · 11-20-2013, 09:21 AM

Check ECU for codes.

Might be a bad coolant temp sensor.

Of course check for Vac leaks.

Maybe this will help out
http://zilvia.net/f/builds-builds-on...ject-sr86.html

ultimateirving · 11-20-2013, 09:38 AM

That really sounds like a stuck open iacv valve try removing it and cleaning and then resetting the idle putting the SR in timing mode

mr.nismo. · 11-26-2013, 07:23 PM

Check your CTS, also 43.5 psi is your fuel pressure w/ vacuum? If so that's too much. Should be 37 w/ vac 43.5 w/o. Do you have a wideband?

11-19-2013, 07:17 PM	#1
marley4us Leaky Injector Join Date: Jun 2010 Location: Milpitas ca Age: 39 Posts: 80 Trader Rating: (0) Feedback Score: 0 reviews	Cold start sr20det in ae86 issue Ok, I figured I would come here and try to get some help. I have searched and read a ton stuff, but I feel like I am at a loss. I have a AE86 with a redtop s13 SR20det. Under cold start, it will immediately die out. If you throttle it a bunch and keep cranking it seems to get it to idle, but rough and you have to feather the throttle until it is fully warmed up. Once it is warmed up, the throttle will idle, but it bounces, from 2000 to about 1500. Some times it will idle ok, but mostly it does this. It is a stock SR20det red top with B.C. 268 cams. An new external walbro 255. Fuel pressure is around 3 bar (43.5 psi) I am running oem 4ac fuel lines to sr20 but it does not seem to effect the fuel pressure. My I swapped my maf, and even tried un plugging it and re plugging it in while the car was on, and it changed the idle slightly but never solved the issue. I installed a old greddy boost gauge, and it says I have 500mm/hg or torr (10psi) vacuum, so maybe I have a boost/vacuum leak... but I am not sure.... The orange wire (cold start map) I read about but I am not sure I understand it... I am not using a SR20DET body harness, so info on that might help too Any help idea's etc. I think this is a common SR20det problem

11-20-2013, 09:21 AM	#3
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Check ECU for codes. Might be a bad coolant temp sensor. Of course check for Vac leaks. Maybe this will help out http://zilvia.net/f/builds-builds-on...ject-sr86.html __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

11-20-2013, 09:38 AM	#4
ultimateirving Zilvia FREAK! Join Date: Nov 2010 Location: arizona Age: 36 Posts: 1,521 Trader Rating: (1) Feedback Score: 1 reviews	That really sounds like a stuck open iacv valve try removing it and cleaning and then resetting the idle putting the SR in timing mode __________________ Z32 with lq4 swap Desert Street Scene \|\| Dssevents.com

11-26-2013, 07:23 PM	#5
mr.nismo. Nissanaholic! Join Date: Feb 2012 Location: Oxnard, CA Age: 30 Posts: 1,890 Trader Rating: (31) Feedback Score: 31 reviews	Cold start sr20det in ae86 issue Check your CTS, also 43.5 psi is your fuel pressure w/ vacuum? If so that's too much. Should be 37 w/ vac 43.5 w/o. Do you have a wideband?

11-19-2013, 07:36 PM	#2
s13mikesr20 Nissanaholic! Join Date: Sep 2011 Location: las vegas Age: 34 Posts: 1,792 Trader Rating: (8) Feedback Score: 8 reviews	i have same prob on my black top mine was tps no getting signal while cold but when it warms up works fine dafuq lol