Car startup issue

  • Updated Latest Activity Bar for Forums main page / Bump Button for The Marketplace / Bigger Fonts / Thread Thumbnails / Similar Threads after post / Dark Mode via header lightbulb / Hi All, the forums have just been upgraded, please bear with us while it is being improved - May 30 2030hrs Please post any feedback here: FAQ Help

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
My car if shutoff for too long it will have this one small issue. Basically after shutoff for >8 hours, on first start up it will always die immediately if i didnt press the gas a bit. To prevent this everytime after shutoff for more than 8 hours, when i turn the key need to give it a bit of gas then only ok.

If shutoff for short period, this issue wont happen. Any thought?

Car is a nissan sentra with na sr20ve engine.

Thanks
 

lsm1991

1,000 RPM Member
Senior Member

lsm1991

1,000 RPM Member
Senior Member
Sep 30, 2011
1,302
148
663
PJ
My car if shutoff for too long it will have this one small issue. Basically after shutoff for >8 hours, on first start up it will always die immediately if i didnt press the gas a bit. To prevent this everytime after shutoff for more than 8 hours, when i turn the key need to give it a bit of gas then only ok.

If shutoff for short period, this issue wont happen. Any thought?

Car is a nissan sentra with na sr20ve engine.

Thanks
does your car have any sort of icv? sounds like a cold start issue.
 

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
does your car have any sort of icv? sounds like a cold start issue.
I dont think its the icv issue. The car idles fine during cold or after warm up. Very solid idle. Just the first start up after sleeping too long it will stumble. Also the car starts easily everytime.
 

lsm1991

1,000 RPM Member
Senior Member

lsm1991

1,000 RPM Member
Senior Member
Sep 30, 2011
1,302
148
663
PJ
I dont think its the icv issue. The car idles fine during cold or after warm up. Very solid idle. Just the first start up after sleeping too long it will stumble. Also the car starts easily everytime.
fuel pump possible? try leave the car in on for abit before cranking?
 

leinnz

Known Member
Senior Member

leinnz

Known Member
Senior Member
Sep 28, 2005
249
28
1,528
what was change recently before the issue happen?
 

vr2turbo

Beyond 20,000 RPM!
Helmet Clan
Moderator

vr2turbo

Beyond 20,000 RPM!
Helmet Clan
Moderator
May 11, 2010
29,260
8,172
1,713
Petaling Jaya
My car if shutoff for too long it will have this one small issue. Basically after shutoff for >8 hours, on first start up it will always die immediately if i didnt press the gas a bit. To prevent this everytime after shutoff for more than 8 hours, when i turn the key need to give it a bit of gas then only ok.

If shutoff for short period, this issue wont happen. Any thought?

Car is a nissan sentra with na sr20ve engine.

Thanks
My VR same problem for years already, so just need to gas a bit then will idle properly.......lol
 

Izso

Boooooossst
Helmet Clan
Moderator

Izso

Boooooossst
Helmet Clan
Moderator
Mar 28, 2004
14,739
6,218
3,213
KL
My car if shutoff for too long it will have this one small issue. Basically after shutoff for >8 hours, on first start up it will always die immediately if i didnt press the gas a bit. To prevent this everytime after shutoff for more than 8 hours, when i turn the key need to give it a bit of gas then only ok.

If shutoff for short period, this issue wont happen. Any thought?

Car is a nissan sentra with na sr20ve engine.

Thanks
Does your SR20 transplant come with a coolant temperature sensor? What ECU are you using? There's two possibilities I can see that's causing this.

1. A faulty coolant temperature sensor that's reading wrongly during cold start hence when you give it some gas the thing straightens out. Once the car is going you're able to idle without holding the gas? You only need to blip the gas?

2. A faulty or going to be faulty fuel regulator and/or fuel pump. How old is your regulator and pump? Maybe it's just time.
 

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
Does your SR20 transplant come with a coolant temperature sensor? What ECU are you using? There's two possibilities I can see that's causing this.

1. A faulty coolant temperature sensor that's reading wrongly during cold start hence when you give it some gas the thing straightens out. Once the car is going you're able to idle without holding the gas? You only need to blip the gas?

2. A faulty or going to be faulty fuel regulator and/or fuel pump. How old is your regulator and pump? Maybe it's just time.
1. Comes with coolant temp sensor. Reading is correct so far, after idle 1-2 minute the temperature will slowly goes up. The car idles fine even when very cold. Just when starting give it a blip of gas, and it will start right up and idles fine. If didnt give blip it will crank a bit more, around 6 turns before start n dies immediately after. Normal crank turn only 2-3 times.

3. Ecu is sr20ve p11 ecu piggyback emanage blue. Originally this engine pairs with sr20ve p12 ecu from factory.
 

Izso

Boooooossst
Helmet Clan
Moderator

Izso

Boooooossst
Helmet Clan
Moderator
Mar 28, 2004
14,739
6,218
3,213
KL
1. Comes with coolant temp sensor. Reading is correct so far, after idle 1-2 minute the temperature will slowly goes up. The car idles fine even when very cold. Just when starting give it a blip of gas, and it will start right up and idles fine. If didnt give blip it will crank a bit more, around 6 turns before start n dies immediately after. Normal crank turn only 2-3 times.

3. Ecu is sr20ve p11 ecu piggyback emanage blue. Originally this engine pairs with sr20ve p12 ecu from factory.
I am not familiar with the P11/12 ECU so can't comment but I suspect it has something to do with that. Cold-start is all the ECU and what sensor data it picks up. So if the coolant temp sensor is working then it might be the parameters of the ecu itself since it's not the original P12? I dunno. Is there some setting in he emanage you can check to check the cold-start?
 

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
I am not familiar with the P11/12 ECU so can't comment but I suspect it has something to do with that. Cold-start is all the ECU and what sensor data it picks up. So if the coolant temp sensor is working then it might be the parameters of the ecu itself since it's not the original P12? I dunno. Is there some setting in he emanage you can check to check the cold-start?
Well even at overseas it is common to switch to p11 ecu when plonking the engine down to sentra b13, because they do not know how to retain the original coil on plug ignition system, so need to switch to distributor type. Hence the change of ecu.

For the emanage, i have no knowledge on how to tune it..
 

gunnerzz

1,500 RPM Member

gunnerzz

1,500 RPM Member
Jul 3, 2014
1,794
560
713
34
Melaka
On my old Pajero, adding grounding cable solve the problem. Starts easily when cold.

When hot, need to crank a bit longer.
 

sweelt

2,000 RPM Member

sweelt

2,000 RPM Member
Nov 6, 2016
2,187
204
163
Penang
Since last time is like that hahaha. Even after full overhaul last year also like that lol. Suspect is nozzle clogged or leaking (where to do nozzle ultrasonic In penang?)
wild guess, was your fuel pump priming when key ON ?
 

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
wild guess, was your fuel pump priming when key ON ?
can hear it prime for 1-2 seconds then quiet. Tried after prime immediately turn, after prime 20 seconds only turn, no wait prime immediately turn, all can start the car. Also all same result, the car will die immediately afterwards. Very rarely it will stumble till almost 0 rpm then somehow manage to go back up the rpm and idle.
 

Izso

Boooooossst
Helmet Clan
Moderator

Izso

Boooooossst
Helmet Clan
Moderator
Mar 28, 2004
14,739
6,218
3,213
KL
can hear it prime for 1-2 seconds then quiet. Tried after prime immediately turn, after prime 20 seconds only turn, no wait prime immediately turn, all can start the car. Also all same result, the car will die immediately afterwards. Very rarely it will stumble till almost 0 rpm then somehow manage to go back up the rpm and idle.
I still think this is something to do with the coolant temp sensor and your ECU. Cuz warmed up the car no issue - I suspect the cold start management of the ECU is not working properly somehow.
 

brokenjars

Known Member

brokenjars

Known Member
Jun 7, 2012
160
10
518
Kedah
I still think this is something to do with the coolant temp sensor and your ECU. Cuz warmed up the car no issue - I suspect the cold start management of the ECU is not working properly somehow.
Comes to think about it, it might be the coolent temp not detected by the ecu. When started in cold, the idle is at 950 rpm. Supposed to be higher i think. After warm up, it will go down to 850.

How do i check whether the ecu is detecting or the coolant temp is not faulty?
 

Izso

Boooooossst
Helmet Clan
Moderator

Izso

Boooooossst
Helmet Clan
Moderator
Mar 28, 2004
14,739
6,218
3,213
KL
Comes to think about it, it might be the coolent temp not detected by the ecu. When started in cold, the idle is at 950 rpm. Supposed to be higher i think. After warm up, it will go down to 850.

How do i check whether the ecu is detecting or the coolant temp is not faulty?
I don't think you can with stock ECU unless you have some sort of diagnostic tool. And you're right, cold idle is usually higher.

You mentioned you changed your coolant temp sensor recently right?