Hot/cold Sr20 hard start issue - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

angel mkiv · 10-17-2015, 03:58 PM

Hey so I have a s13 sr20 with a power FC l-jetro that has been tuned. Before I blame the tune I wanna see if anyone has any suggestions. So basically either hot or cold it will take 3-4 cranking sessions for it to finally start. And while it's cold I have to wait 5-7min before I can drive it since if I touch the gas pedal it just stumbles and dies. I already checked for the starter 12v signal wire at the ecu and it's fine.

cotbu · 10-17-2015, 07:54 PM

3-4 cranks then fire is normal, and you should wait till the engine is warm before you drive. So let's say you just want it a certain in way, ok!

Slow cranking and fast cranking make a difference, both will have 12v at the starter but a bad/weak starter could be the culprit for the slow crank.

I've replaced starters and the same amount of revolutions seem to take place, but it spins the engine faster as a result the engine fires at what seems like a shorter crank. Htms

Strong compression may result in slow cranking, but valve timing might be an issue. Check verify timing.

The sr uses batch fire for startup so all the injectors fire at the same time until the ecu detects the engine is running. So the engine may have excessive fuel to burn off and the timing is probably not optimal for you to just take off and drive, even like a normal person, I've Tuned issues like that out, so again pretty normal. Normal means everything else is probably setup ok without ecu codes and or boost leaks etc. Everything else means all the stuff you didn’t check like wire corrosion, grounds etc. Changing spark plugs is usually a quick fix but a bandaid fix, IMHO.

Sent from a Highly Tuned Note 4.!!!

angel mkiv · 10-18-2015, 01:56 AM

I didn't mean 3-4 crank revolutions I ment like 3-4 cranking sessions of like 3-5 seconds. And that's both hot and cold. And I know you should let your car warm up but it shouldn't die if you hit the gas or even attempt to move it. The timing was set before the tune and the cas bolt in centered still so I know it hasn't moved. It's a pretty fresh rebuild with a wiring specialties pro harness. Everything runs perfect aside from the starting issue.

angel mkiv · 10-18-2015, 01:59 AM

And no it's not a slow crank. It cranks over fast/normal.

cotbu · 10-18-2015, 09:11 AM

Well then apparently nothing is wrong. The ecu controls timing, fuel and spark based on certain sensors, so just because the "stationary bolt" doesn't move, does not mean timing hasn't changed. Check codes for coolant temp sensor.

Sent from a Highly Tuned Note 4.5!!!

10-17-2015, 03:58 PM	#1
angel mkiv Zilvia Addict Join Date: Sep 2009 Location: Seattle, wa Posts: 727 Trader Rating: (4) Feedback Score: 4 reviews	Hot/cold Sr20 hard start issue Hey so I have a s13 sr20 with a power FC l-jetro that has been tuned. Before I blame the tune I wanna see if anyone has any suggestions. So basically either hot or cold it will take 3-4 cranking sessions for it to finally start. And while it's cold I have to wait 5-7min before I can drive it since if I touch the gas pedal it just stumbles and dies. I already checked for the starter 12v signal wire at the ecu and it's fine. __________________ Instagram username:angelmkiv

10-17-2015, 07:54 PM	#2
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 49 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	3-4 cranks then fire is normal, and you should wait till the engine is warm before you drive. So let's say you just want it a certain in way, ok! Slow cranking and fast cranking make a difference, both will have 12v at the starter but a bad/weak starter could be the culprit for the slow crank. I've replaced starters and the same amount of revolutions seem to take place, but it spins the engine faster as a result the engine fires at what seems like a shorter crank. Htms Strong compression may result in slow cranking, but valve timing might be an issue. Check verify timing. The sr uses batch fire for startup so all the injectors fire at the same time until the ecu detects the engine is running. So the engine may have excessive fuel to burn off and the timing is probably not optimal for you to just take off and drive, even like a normal person, I've Tuned issues like that out, so again pretty normal. Normal means everything else is probably setup ok without ecu codes and or boost leaks etc. Everything else means all the stuff you didn’t check like wire corrosion, grounds etc. Changing spark plugs is usually a quick fix but a bandaid fix, IMHO. Sent from a Highly Tuned Note 4.!!! __________________ LoverTechnologies "Half Broken Things!"

10-18-2015, 01:56 AM	#3
angel mkiv Zilvia Addict Join Date: Sep 2009 Location: Seattle, wa Posts: 727 Trader Rating: (4) Feedback Score: 4 reviews	I didn't mean 3-4 crank revolutions I ment like 3-4 cranking sessions of like 3-5 seconds. And that's both hot and cold. And I know you should let your car warm up but it shouldn't die if you hit the gas or even attempt to move it. The timing was set before the tune and the cas bolt in centered still so I know it hasn't moved. It's a pretty fresh rebuild with a wiring specialties pro harness. Everything runs perfect aside from the starting issue. __________________ Instagram username:angelmkiv

10-18-2015, 01:59 AM	#4
angel mkiv Zilvia Addict Join Date: Sep 2009 Location: Seattle, wa Posts: 727 Trader Rating: (4) Feedback Score: 4 reviews	And no it's not a slow crank. It cranks over fast/normal. __________________ Instagram username:angelmkiv

10-18-2015, 09:11 AM	#5
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 49 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Well then apparently nothing is wrong. The ecu controls timing, fuel and spark based on certain sensors, so just because the "stationary bolt" doesn't move, does not mean timing hasn't changed. Check codes for coolant temp sensor. Sent from a Highly Tuned Note 4.5!!! __________________ LoverTechnologies "Half Broken Things!"