Sr20det redtop problem!! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ll_EvOluTIoN · 02-18-2011, 07:38 AM

So just did my swap and I'm having an idle problem. It seems to be idling around 1000rpm(tach nonop) then it seems to cut out for a sec. I was checking the injector pulse with test light and when the engine cuts out the injectors stop pulsing.

I checked tps adjustment an it's at .4v. I'm getting spark at all plugs. New spark plugs n gas. New stock injectors spray great. I switched between 3 ignitor chips n same prob. Switched in known good ecu. Same prob.

Any ideas of what it could be?

92dagrey · 02-19-2011, 10:49 AM

when you say "cut out" do u mean the engine fully dies or it almost dies n then barely comes back to life? There could be some kinda short thats happening. check ecu for codes

ll_EvOluTIoN · 02-19-2011, 01:36 PM

No. Its like a momentary drop in idle it doesn't cut out enough to die or almost die

92dagrey · 02-19-2011, 02:30 PM

do all the injectors cut out at the same time?

ll_EvOluTIoN · 02-19-2011, 03:33 PM

Not sure. Ran codes n got 55. Checked tps it's .48v-3.8v wot. Maf is .8v key on engine off.

ll_EvOluTIoN · 02-22-2011, 01:56 AM

Bump!!! Still need help

anarchyperf · 02-22-2011, 03:58 AM

I would try swapping out your maf first. Also sounds like you might have a loose/broken wire in the harness

codyace · 02-22-2011, 07:37 AM

How does the car drive?

ll_EvOluTIoN · 02-22-2011, 11:16 PM

I haven't driven it yet I'm afraid it will damage the engine.

codyace · 02-23-2011, 09:43 PM

Is the engine itself literally cutting out, or is it just sorta/kind stumbly at times?

EDIT: Can you take a video with your cell phone and post it to youtube for us?

ll_EvOluTIoN · 02-23-2011, 09:58 PM

It's cutting out and it's consistent. It doesn't die cuz it's idling high so when it cuts out momentarily. Even if I accelerate a little higher it will still cut out the same unless I hold it at wot

ll_EvOluTIoN · 02-28-2011, 07:21 PM

So the injectors are cutting out. I tried a new tps n it fixed the idle for 5 min n did the same. So put a new maf and the problem goes away untill I hit the throttle. Then idles bad again. Now today no matter what I do it idles bad. Here's what I got.

YouTube - Sr20det problem

codyace · 02-28-2011, 09:16 PM

It sounds like you have a HUGE vacuum leak, or something wired incorrectly.

slomar91 · 02-28-2011, 09:33 PM

Quote:

Originally Posted by codyace

It sounds like you have a HUGE vacuum leak, or something wired incorrectly.

+1 on the vacuum leak.

Kingtal0n · 03-01-2011, 12:43 AM

the computer has a method for controlling fuel when the tps is untouched.

if anyone with an SR20det raises the idle without moving the tps eventually the engine hits a cut off point for fueling, its called idle fuel cut rpm. For instance if the engine is getting extra air from a vacuum leak and the idle raises to 1200rpm or so, the fuel will cut if the tps is unmoved (no one is touching the gas pedal). this is because the ecu thinks the car is in a deceleration. You want the fuel to cut when you lift your foot from the gas pedal so the engine can brake to a lower rpm.

anyways, my point is that it sounds like you have a vacuum leak, and this raises the idle to the fuel-cut RPM which causes the engine to sudden "cut out" till the rpm drops back down.

find the air leak and create a stable idle, the sudden cutting out is an actual proper mechanism within the ECU nothing is wrong with it.

DirtyLoud · 03-01-2011, 12:48 AM

Quote:

Originally Posted by Kingtal0n

the computer has a method for controlling fuel when the tps is untouched.

if anyone with an SR20det raises the idle without moving the tps eventually the engine hits a cut off point for fueling, its called idle fuel cut rpm. For instance if the engine is getting extra air from a vacuum leak and the idle raises to 1200rpm or so, the fuel will cut if the tps is unmoved (no one is touching the gas pedal). this is because the ecu thinks the car is in a deceleration. You want the fuel to cut when you lift your foot from the gas pedal so the engine can brake to a lower rpm.

anyways, my point is that it sounds like you have a vacuum leak, and this raises the idle to the fuel-cut RPM which causes the engine to sudden "cut out" till the rpm drops back down.

find the air leak and create a stable idle, the sudden cutting out is an actual proper mechanism within the ECU nothing is wrong with it.

+1
I'm gonna have to go with what he said!

ll_EvOluTIoN · 03-01-2011, 10:51 AM

Thanks that was a pretty awesome explanation. I'm gonna make boost leak tester n see what's up. Thanks for the input!

ll_EvOluTIoN · 03-01-2011, 05:44 PM

So made my boost leak tester n sure enough. Intercooler is leaking hardcore!!! Thanks for the help everyone.

codyace · 03-01-2011, 09:49 PM

Nice stuff! Awesome troubleshooting by everyone!

anarchyperf · 03-01-2011, 10:48 PM

Quote:

Originally Posted by ll_EvOluTIoN

So made my boost leak tester n sure enough. Intercooler is leaking hardcore!!! Thanks for the help everyone.

Good find. Let me know if you plan on ordering a new intercooler. I'll hook you up.

ll_EvOluTIoN · 03-17-2011, 08:24 PM

Hey guys here's an update. I replaced my intercooler and checked for leaks got rid of most of them holds pressure for a min then it goes back to zero. I started it up still cutting out. Drove it just for kicks and when I was almost to my driveway it started revving on it's own so I shut it off before it went up to high. Since I tach wasn't working didn't want to permenently damage engine.

Now I put a decent tps and fresh harness. Same ecu already tried a different maf same prob. Got my rps working

going forward atleast. Tach bounces off 1500 to 2000 rpm. I disconnected the iacv to see what happens wile running and nothing changed. Still cutting out

Kemps · 03-17-2011, 08:30 PM

So the engine harness has been replaced? Change the ecu and try again, could very well be a wiring problem.

ll_EvOluTIoN · 03-17-2011, 08:35 PM

Yea I have a brand new harness. I changed the ecu also to my Buddys ecu I know it fir sure works cuz it just came off his running car.

Should the car turn off when I disconnect the iacv?

Kemps · 03-17-2011, 08:44 PM

Did you clean the IAC? Spray carburetor cleaner into the IAC passages and see if that works, if not then replace it and see if the idle comes back.

ll_EvOluTIoN · 03-17-2011, 08:48 PM

Haven't done that yet. So just spray into where the 2 hose connect to right?

Kemps · 03-17-2011, 08:50 PM

ya just to clean out all the carbon build up in it

ll_EvOluTIoN · 03-17-2011, 08:53 PM

Thanks for the help.
You think that might have caused that random rev up as well?

SR20Driftking4lyf · 03-17-2011, 09:11 PM

I did this one time.....smelled like hell, I would do it outside and not in a garage

Kemps · 03-17-2011, 09:17 PM

it very well could be

ll_EvOluTIoN · 03-21-2011, 04:50 PM

So I took the iacv all the way off n super cleaned it. Same problem occurs idle bounces from 1500to 2000 n still have the injector cutt off.

Y is it that when I unplug my tps it revs up instead of getting regulated by ecu. Is the iacv used to reg the idle when tps is disconnected?

This same thing happens when I unplug coolant temp sensor.

I did a boost leak test n it holds pressure but looses it after 1min or so. I fill it to 10 psi. Does that leak seam big enough to keep causing injector cutt off?

02-18-2011, 07:38 AM	#1
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Sr20det redtop problem!! So just did my swap and I'm having an idle problem. It seems to be idling around 1000rpm(tach nonop) then it seems to cut out for a sec. I was checking the injector pulse with test light and when the engine cuts out the injectors stop pulsing. I checked tps adjustment an it's at .4v. I'm getting spark at all plugs. New spark plugs n gas. New stock injectors spray great. I switched between 3 ignitor chips n same prob. Switched in known good ecu. Same prob. Any ideas of what it could be?

02-22-2011, 03:58 AM	#7
anarchyperf Zilvia Member Join Date: Dec 2010 Location: Nazareth, Pa Age: 40 Posts: 194 Trader Rating: (1) Feedback Score: 1 reviews	I would try swapping out your maf first. Also sounds like you might have a loose/broken wire in the harness __________________ www.anarchyperformance.com - Your source for 240sx Performance! https://www.facebook.com/anarchyperformance - Like us on facebook Email: [email protected]

02-22-2011, 07:37 AM	#8
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 40 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	How does the car drive? __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

02-23-2011, 09:43 PM	#10
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 40 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	Is the engine itself literally cutting out, or is it just sorta/kind stumbly at times? EDIT: Can you take a video with your cell phone and post it to youtube for us? __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

02-28-2011, 09:16 PM	#13
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 40 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	It sounds like you have a HUGE vacuum leak, or something wired incorrectly. __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

02-19-2011, 10:49 AM	#2
92dagrey Join Date: Feb 2011 Location: Harrisburg, PA Age: 36 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	when you say "cut out" do u mean the engine fully dies or it almost dies n then barely comes back to life? There could be some kinda short thats happening. check ecu for codes

02-19-2011, 01:36 PM	#3
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	No. Its like a momentary drop in idle it doesn't cut out enough to die or almost die

02-19-2011, 02:30 PM	#4
92dagrey Join Date: Feb 2011 Location: Harrisburg, PA Age: 36 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	do all the injectors cut out at the same time?

02-19-2011, 03:33 PM	#5
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Not sure. Ran codes n got 55. Checked tps it's .48v-3.8v wot. Maf is .8v key on engine off.

02-22-2011, 01:56 AM	#6
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Bump!!! Still need help

02-22-2011, 11:16 PM	#9
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	I haven't driven it yet I'm afraid it will damage the engine.

02-23-2011, 09:58 PM	#11
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	It's cutting out and it's consistent. It doesn't die cuz it's idling high so when it cuts out momentarily. Even if I accelerate a little higher it will still cut out the same unless I hold it at wot

02-28-2011, 07:21 PM	#12
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	So the injectors are cutting out. I tried a new tps n it fixed the idle for 5 min n did the same. So put a new maf and the problem goes away untill I hit the throttle. Then idles bad again. Now today no matter what I do it idles bad. Here's what I got. YouTube - Sr20det problem

03-01-2011, 12:43 AM	#15
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 42 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	the computer has a method for controlling fuel when the tps is untouched. if anyone with an SR20det raises the idle without moving the tps eventually the engine hits a cut off point for fueling, its called idle fuel cut rpm. For instance if the engine is getting extra air from a vacuum leak and the idle raises to 1200rpm or so, the fuel will cut if the tps is unmoved (no one is touching the gas pedal). this is because the ecu thinks the car is in a deceleration. You want the fuel to cut when you lift your foot from the gas pedal so the engine can brake to a lower rpm. anyways, my point is that it sounds like you have a vacuum leak, and this raises the idle to the fuel-cut RPM which causes the engine to sudden "cut out" till the rpm drops back down. find the air leak and create a stable idle, the sudden cutting out is an actual proper mechanism within the ECU nothing is wrong with it.

03-01-2011, 10:51 AM	#17
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Thanks that was a pretty awesome explanation. I'm gonna make boost leak tester n see what's up. Thanks for the input!

03-01-2011, 05:44 PM	#18
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	So made my boost leak tester n sure enough. Intercooler is leaking hardcore!!! Thanks for the help everyone.

03-01-2011, 09:49 PM	#19
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 40 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	Nice stuff! Awesome troubleshooting by everyone! __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

03-17-2011, 08:24 PM	#21
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Hey guys here's an update. I replaced my intercooler and checked for leaks got rid of most of them holds pressure for a min then it goes back to zero. I started it up still cutting out. Drove it just for kicks and when I was almost to my driveway it started revving on it's own so I shut it off before it went up to high. Since I tach wasn't working didn't want to permenently damage engine. Now I put a decent tps and fresh harness. Same ecu already tried a different maf same prob. Got my rps working going forward atleast. Tach bounces off 1500 to 2000 rpm. I disconnected the iacv to see what happens wile running and nothing changed. Still cutting out

03-17-2011, 08:30 PM	#22
Kemps BANNED Join Date: Mar 2011 Location: Orange County Age: 36 Posts: 47 Trader Rating: (0) Feedback Score: 0 reviews	So the engine harness has been replaced? Change the ecu and try again, could very well be a wiring problem.

03-17-2011, 08:35 PM	#23
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Yea I have a brand new harness. I changed the ecu also to my Buddys ecu I know it fir sure works cuz it just came off his running car. Should the car turn off when I disconnect the iacv?

03-17-2011, 08:44 PM	#24
Kemps BANNED Join Date: Mar 2011 Location: Orange County Age: 36 Posts: 47 Trader Rating: (0) Feedback Score: 0 reviews	Did you clean the IAC? Spray carburetor cleaner into the IAC passages and see if that works, if not then replace it and see if the idle comes back.

03-17-2011, 08:48 PM	#25
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Haven't done that yet. So just spray into where the 2 hose connect to right?

03-17-2011, 08:50 PM	#26
Kemps BANNED Join Date: Mar 2011 Location: Orange County Age: 36 Posts: 47 Trader Rating: (0) Feedback Score: 0 reviews	ya just to clean out all the carbon build up in it

03-17-2011, 08:53 PM	#27
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	Thanks for the help. You think that might have caused that random rev up as well?

03-17-2011, 09:11 PM	#28
SR20Driftking4lyf Leaky Injector Join Date: Oct 2005 Location: Florida Posts: 66 Trader Rating: (0) Feedback Score: 0 reviews	I did this one time.....smelled like hell, I would do it outside and not in a garage

03-17-2011, 09:17 PM	#29
Kemps BANNED Join Date: Mar 2011 Location: Orange County Age: 36 Posts: 47 Trader Rating: (0) Feedback Score: 0 reviews	it very well could be

03-21-2011, 04:50 PM	#30
ll_EvOluTIoN Zilvia Member Join Date: Jan 2005 Location: Elk Grove, Killa Cali. Posts: 277 Trader Rating: (1) Feedback Score: 1 reviews	So I took the iacv all the way off n super cleaned it. Same problem occurs idle bounces from 1500to 2000 n still have the injector cutt off. Y is it that when I unplug my tps it revs up instead of getting regulated by ecu. Is the iacv used to reg the idle when tps is disconnected? This same thing happens when I unplug coolant temp sensor. I did a boost leak test n it holds pressure but looses it after 1min or so. I fill it to 10 psi. Does that leak seam big enough to keep causing injector cutt off? Last edited by ll_EvOluTIoN; 03-22-2011 at 02:16 AM..