Rb20det won't start

[JDMfreak07]

I searched around with my issue and couldn't really find anything, so i'll post in here hoping someone knows something.

I have an rb20det in one of my s13's. Problem being, the car will not start without me helping it with the gas pedal a bit. When it gets pretty cold out (like it is now) the car barely starts. I literally sat and cranked it 7-8 times before it finally turned over. And that was with me pushing the gas pedal in a good bit, and i tried to start it yesterday it did not want to.
Also, the weird part is once the motor is at normal operating temp it will start first try every time. No pedal assistance, nothing. The colder outside it gets the harder it is to start. When its like 70 degrees out you have to try to start it maybe 2-3 times, after that it will turn over. Any help is appreciated.

[kpjo4]

Time to compression test it. Try this out, remove all 6 spark plugs, add a cap full of oil in each bore, plug the sparkplugs back in and wire it up, try cranking it. If it fires easier, you obviously have low compression in the block, but it is still possible for your head or gasket to be leaking.

When the motor is warm, the piston rings expand helping to seal better; yielding to more compression. That may be the reason why it's easier to fire your motor on a warmed up motor.

[JDMfreak07]

Thanks for the help kpjo4, i will try that and get back to you.
What other suggestions if it was not the compression or a leak the head and gasket?

[JDMfreak07]

Thanks for the help kpjo4, i will try that and get back to you.
What other suggestions if it was not the compression or a leak the head and gasket?

[g35gabby]

Could be something as simple as the fuel pump or battery. what does it do when it doesn't crank over, as in if you don't pump the gas? done it just crank and fail to start?

[shocker854]

Check your IACV? I've heard of them giving problems upon cold starts as well.


Theres a thread for you to check out as well.

http://www.skylinesaustralia.com/forums/topic/281410-cold-start-issue/

[JDMfreak07]

It tries to start itself, or keeps on cracking, the last time i tried to turn it on, the battery became weak!

[JDMfreak07]

Thanks shocker854, i will check it and get back to you.

[JDMfreak07]

It surely needs a new battery, it cracked on today, but had to help it with pushing the pedal 3 times and weather was warmer.

[240boi115]

honestly that sounds like a starter issue bro...

[JDMfreak07]

I checked the starter, looks fine to me. it cranks but sometimes needs more time and a little help pushing the pedal.
and when it is really cold, it won't start sometimes.

[240boi115]

try tapping it with a screwdriver ( the starter) while your trying to start it.. if that helps then it is indeed your starter

[240boi115]

never hurts to get a new battery either though..

[JDMfreak07]

i am getting a new one tomorrow. and i will try doing that with my starter. i just hope it is not a big issue.
Thanks for the help

[Yellow4g63]

There is supposed to be a 5v signal wire going to the ecu if I remember right. This tells the ecu that the car is trying to start. I don't remember what pin it is either been too long. I had that problem when I had a S13 RB20, wired it up and it started like a champ when cold.

[JDMfreak07]

I will check that out.
Could you check which pin it is ? Thanks !

[Yellow4g63]

Don't have a S13 anymore that's why I don't remember.

[Yellow4g63]

RB20 DASH PLUG

BLACK/PINK-------------------- FUEL PUMP
YELLOW/RED------------------ TACH SIGNAL
YELLOW/GREEN-------------- VEHICLE SPEED SENSOR
BLACK/YELLOW-------------- IGNITION START SIGNAL
ORANGE/BLACK-------------- CHECK ENGINE LIGHT
TEAL----------------------------- AC RELAY
TEAL/RED---------------------- AC SWITCH
*NOTE*------ FSM states PIN #32/Check engine light as PINK/BLACK
But mine was ORANGE/BLACK

S13 WIRE/RB20 WIRE
SOLID/STRIPE

DASH PLUG WIRING

YELLOW/RED------------------- TACH SIGNAL------------------ YELLOW/RED
YELLOW/GREEN--------------- SPEED SIGNAL----------------- YELLOW/GREEN
ORANGE-------------------------- IGNITION START-------------- BLACK/YELLOW
*NOTE* The BLACK/YELLOW wire should trace back to PIN #43, which you might have read about on the other guides.
BLACK/PINK---------------------FUEL PUMP---------------------- BLACK/PINK
S13 wire found on the BROWN plug. RB20 wire found on the DASH PLUG.
I actually extended the wire from the dash plug to the brown to make sure it would reach
and plug in.
RED------------------------------ CHECK ENGINE LIGHT-------------- ORANGE/BLACK
BLACK---------------------------- GROUND

http://www.s-chassis.com/resources/wiki/images/c/c8/ECURB20DET.jpg