Motor Stumbles on Cold Startups

[Mario]

Just recently (last couple weeks) the motor takes a good 3-4 seconds before it will actually begin to crankover and start. Seems almost like it is starving for fuel or something. It has 2 step colder plugs... plug wires both new.

What would cause this and what would remedy it?

[john]

Are you running sufficient boost or nitrous to validate using 2 heat range colder plugs? They are not cleaning themselves, you can pretty much be assured...

[exciv2000]

what weight oil are you using?

[Mario]

John - haven't run nitrous yet, just gotta mount the bottle to finish it... and I may run it today, although I dunno if this weather will work for it. Also, it'll be a 75 dry shot on a ZEX system.

Scott - I am using 5w30 fully synthetic Mobil 1 oil with PureOne filter.

[exciv2000]

I'd wait till it gets warmer. The oil should be fine, just wanted to make sure you weren't running something like 15w50... that would make a difference.

[Dustin]

John - haven't run nitrous yet, just gotta mount the bottle to finish it... and I may run it today, although I dunno if this weather will work for it. Also, it'll be a 75 dry shot on a ZEX system.

Scott - I am using 5w30 fully synthetic Mobil 1 oil with PureOne filter.

Change plugs at the track, when you will actually use the nitrous....

[HONDA GHANDI]

If you have the timing retarded for N20 that will cause problems starting too. Cold engines like a little advance to get started.

[Mario]

Dustin - I was under the impression they'd be fine for daily driving as well? :confused:

Tobi - no timing retarded, it's whatever you had it when I bought the car from you.

Thanks for all the input guys. :)

[ryanman]

Umm, 2 step colder plugs will definately have an effect on cold start ups, from my experience anyways.

[exciv2000]

not in my experience.

[john]

Use your normal heat range plugs for daily driving.

FWIW, a generic rule of thumb is 1 heat range colder for each add'l 50-100 hp added.

I took the supra from 320 crank hp to 730 crank hp and went 1 heat range colder. Anything more than that and the plugs weren't able to self-clean.

[ryanman]

:werd:

I normally go by the rule of 1 step colder plug per 50hp shot and always worked fantastic.

[Mario]

Thanks for the information guys, I definitely appreciate it! So 1 range colder plugs will work then. Thanks!