Cold start issue 4th gen jdm vtec - any suggestions?

[vanzep]

jdm car so no need for fuses in bay 6&12

[vanzep]

any thoughts on why 20amp fuse in 5 (voltage regulator)

[wurlycorner]

Would need to check the service manual. That has all the wiring diagrams and fuse permutations for all markets.

[vanzep]

ok im going to leave the fuses as they are as i doubt this has anything to do with cold start issue.
i will try starting it using a battery booster - if it starts first time then it will point to a weak spark/battery problem if it doesnt start first time then it will point to a fuel/sensor issue.

[vanzep]

Battery booster used this morning and it started on 2nd attempt
same as
Holts cold start - started on 2nd attempt
Dont know if either of these "tests" prove anything
if neither of the above is used then it takes 4 attempts to start it from cold when left overnight

Tomorrow morning Im going to try Davies suggestion of turning the ignition on and off 3 or 4 times and see if this builds fuel pressure

[vanzep]

turning ignition on and off to build fuel pressure had no effect at all

but this morning after sub zero temps overnight i got it start on the button, first turn of the key - mind u i had sprayed some cold start into the intake
so by my reckoning its got to be fuel related in that its not getting a rich enough mixture - i will be checking out any sensors that have input and then onto the fuel regulator and pump.

thanks for all the helpful suggestions

[Prelude danny]

This is very interesting, even I want to know what it is now lol

Sent from my E6653 using Tapatalk

[hondaddict]

I know it may looks stupid but it could be caused by a weak starter motor... , you should try to clean it .

[JEBB4]

Tested coolant sensor? Sounds suspect if starts better with a drastic temperature change..

Edit: coolant temp sensor (one in thermostat housing with green plug I think) will alter fuel delivery rate from injectors.. A resistance test with a basic multimeter and a bowl of boiling water is easy way to test, you may not need to the boiling water though as your problem is when cold, unsure on what the resistance should be but workshop manual will have this info.. Hope this helps

Edit 2: I see you have swapped the sensor once

[vanzep]

i changed the white coolant temp sensor at the side of the block but ive not looked at the green one on the thermostat housing