Sr20det s13 wiring question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Dsmguy1993 · 03-09-2021, 12:01 AM

So I have a rebuilt sr20det s13 in my car it runs good and I got the alternator to start charging the strange thing is even after I installed a new optima yellowtop and secured my battery ground by using one that fits the terminal very tightly, I notice that basically if I drive for a bit say 20 minutes then shut the car off and come back like hours later it doesnt likee to start, but if you start it up right after shutting it off it starts up perfectly! So my positive battery cable connects to the fuse box from there a 4 gauge wire goes to my alternator positive post and from my alternator theres a 4awg wire to the starter and on the starter is my harness constant 12v (wiring specialties pro harness). So do you think its having a hard time initially cranking and only crank easy when jumper cables are involved orr do you think my battery positive should go straight to the starter and only the alternator connects to the fuse box this way the starter gets direct power? Thanks for any help btw my sr runs good otherwise afrs are looking good the starter receives constant 12v ive seen it with multimeter it cranks up perfectly when jumper cables are used btw.

jedi03 · 03-10-2021, 07:24 AM

having same issue on fc swapped with sr...am going to try a relay for the solenoid as well as a battery shutoff for when done driving it an see...I was going to try a solar battery maintainer but not sure how much that might help...

*brndck* · 03-10-2021, 10:55 AM

ok when it won't start, whats the battery voltage?

you may have a parasitic draw, but to drain down in just an hour or two it would have to be a pretty big load.

Dsmguy1993 · 03-10-2021, 11:17 AM

I fixed the issue guys I wired my positive cable to the start directly using a 4 gauge wire to connect the starter and positive cable as well as the small 12v starter/harness power eyelet. From the starter to alternator its a small 4awg wire length and from alternator to fuse box its another 4awg wire. Now my car cranks up perfectly fine and runs good I had it at the mall yesterday I also installed an optima yellowtop battery and yes they are worth it I notice improvement. Yeah my car starts and runs fine now also if you have this issue drive it around for at least 20-30 minutes so the alternator can recharges it. previously when I had the wiring like starter to alternator then alternator to fuse box and my positive cable connects there when I would try cranking it with 13v in my battery itll drop to 12.7 and not crank unless jumper cables were involved. Its more a current issue than anything I say use 2 gauge wire for the starter but the store only har 4 so I used that instead and it works just fine how its wired makes a difference imo.

Kingtal0n · 03-10-2021, 04:17 PM

probably bad grounds in combination with a leaking fuel pump check valve.

An sr20det can crank over using a lawn mower battery. I know somebody who ran a $33 home depot tractor batt for years. It doesn't take much to get that engine going. You should not be seeing massive voltage drop and dimming lights etc... unless the wiring is crappy

*brndck* · 03-10-2021, 04:31 PM

Quote:

Originally Posted by Kingtal0n

probably bad grounds in combination with a leaking fuel pump check valve.

An sr20det can crank over using a lawn mower battery. I know somebody who ran a $33 home depot tractor batt for years. It doesn't take much to get that engine going. You should not be seeing massive voltage drop and dimming lights etc... unless the wiring is crappy

I ran an interstate lawn tractor battery on my s13 (redtop sr20) for like 4 years. zero issues.

Dsmguy1993 · 03-10-2021, 11:24 PM

could be bad grounds maybe who knows I have a thick ground cable that connects my cylinder head to the car body along with the battery negative cable which I have connected through the passenger seat bolt. In regards to a leaking fuel check valve my line runs to the filter and from there to the feed then the regulator goes to return not too sure what the check valve is but all my fuel connections are definitely on tight fuel pump primes good im
using a walboro 255. Ill let you guys know if it keeps having this issue but I was just driving it around earlier today seems fine right now.

03-09-2021, 12:01 AM	#1
Dsmguy1993 Leaky Injector Join Date: Aug 2019 Location: Illinois Age: 30 Posts: 135 Trader Rating: (0) Feedback Score: 0 reviews	Sr20det s13 wiring question So I have a rebuilt sr20det s13 in my car it runs good and I got the alternator to start charging the strange thing is even after I installed a new optima yellowtop and secured my battery ground by using one that fits the terminal very tightly, I notice that basically if I drive for a bit say 20 minutes then shut the car off and come back like hours later it doesnt likee to start, but if you start it up right after shutting it off it starts up perfectly! So my positive battery cable connects to the fuse box from there a 4 gauge wire goes to my alternator positive post and from my alternator theres a 4awg wire to the starter and on the starter is my harness constant 12v (wiring specialties pro harness). So do you think its having a hard time initially cranking and only crank easy when jumper cables are involved orr do you think my battery positive should go straight to the starter and only the alternator connects to the fuse box this way the starter gets direct power? Thanks for any help btw my sr runs good otherwise afrs are looking good the starter receives constant 12v ive seen it with multimeter it cranks up perfectly when jumper cables are used btw.

03-10-2021, 07:24 AM	#2
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,837 Trader Rating: (8) Feedback Score: 8 reviews	having same issue on fc swapped with sr...am going to try a relay for the solenoid as well as a battery shutoff for when done driving it an see...I was going to try a solar battery maintainer but not sure how much that might help...

03-10-2021, 11:17 AM	#4
Dsmguy1993 Leaky Injector Join Date: Aug 2019 Location: Illinois Age: 30 Posts: 135 Trader Rating: (0) Feedback Score: 0 reviews	I fixed the issue guys I wired my positive cable to the start directly using a 4 gauge wire to connect the starter and positive cable as well as the small 12v starter/harness power eyelet. From the starter to alternator its a small 4awg wire length and from alternator to fuse box its another 4awg wire. Now my car cranks up perfectly fine and runs good I had it at the mall yesterday I also installed an optima yellowtop battery and yes they are worth it I notice improvement. Yeah my car starts and runs fine now also if you have this issue drive it around for at least 20-30 minutes so the alternator can recharges it. previously when I had the wiring like starter to alternator then alternator to fuse box and my positive cable connects there when I would try cranking it with 13v in my battery itll drop to 12.7 and not crank unless jumper cables were involved. Its more a current issue than anything I say use 2 gauge wire for the starter but the store only har 4 so I used that instead and it works just fine how its wired makes a difference imo.

03-10-2021, 04:17 PM	#5
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 41 Posts: 4,829 Trader Rating: (17) Feedback Score: 17 reviews	probably bad grounds in combination with a leaking fuel pump check valve. An sr20det can crank over using a lawn mower battery. I know somebody who ran a $33 home depot tractor batt for years. It doesn't take much to get that engine going. You should not be seeing massive voltage drop and dimming lights etc... unless the wiring is crappy

03-10-2021, 11:24 PM	#7
Dsmguy1993 Leaky Injector Join Date: Aug 2019 Location: Illinois Age: 30 Posts: 135 Trader Rating: (0) Feedback Score: 0 reviews	could be bad grounds maybe who knows I have a thick ground cable that connects my cylinder head to the car body along with the battery negative cable which I have connected through the passenger seat bolt. In regards to a leaking fuel check valve my line runs to the filter and from there to the feed then the regulator goes to return not too sure what the check valve is but all my fuel connections are definitely on tight fuel pump primes good im using a walboro 255. Ill let you guys know if it keeps having this issue but I was just driving it around earlier today seems fine right now.