Colder = Less Crank Time?

[babyivan]

Originally Posted By: 01rangerxl
Originally Posted By: Clevy
Originally Posted By: jsfalls
All the sensors are telling the computer the engine is cold, and gives it a richer mixture. Some engines even have a cold start injector that does nothing but spray in extra fuel when first starting the engine when cold.



What engines are those that come with the extra injector for cold starts?


A lot of older GM engines with early multiport injection had a cold start injector, like late 80s F-Bodies.

Are you sure about that?

My '87 3.8 mpfi does not have a cold start injector, but rather uses the IAC (idle air control valve) to increase air to the to the intake via a pintle controlled by a stepper motor attached to the throttle body.
The ECU gets readings from the coolant temp sensor, which in turn adjusts the air flow via the IAC increasing idle (more air = higher idle/increased fuel demand). Once engine temp rises, ECU adjusts the IAC and idle rpm lowers.

IIRC, my previous F body Firebird 5.0 TPI had the same set up.

I once had an '88 Camry (3SFE) that utilized a cold start injector rather than an IAC set up. They were prone to get internally leaky, but super easy to change out. I miss that car! The 3SFE was by far the easiest car to work on... not all that powerful, but super reliable

 

[SwampSurvivor]

Originally Posted By: dlundblad
Originally Posted By: Vikas
two second of cranking? That is a L O N G crank time!


Renix 4.0 engines are notorious for this. Lol.




I don't think I've ever seen a Renix 4.0L engine that would start with less than 10 seconds of cranking.

 

[gregk24]

My Accord seems to take LONGER in the cold, crank speed slows down significantly as well. Has a relatively new battery as well.

 

[eljefino]

My neon is on the list of things that start faster in the cold. I figured it held off on injectors until 4 revs (like a ford 4.6) to build oil pressure before lighting off, most of the time. But an exception in the programming for extreme cold kicked in.

 

[Traction]

After growing up with carburetor engines, everything has a short crank time. Had my 08 Chevy for a few months, until my neighbor told me, you just bump the key, and it will crank till it starts. They have come a long way from 6 volt starters on a Model A with 30W oil. Can't even imagine trying to start the early cars in cold weather with a crank. No problems nowadays.

 

[01rangerxl]

Originally Posted By: babyivan
Originally Posted By: 01rangerxl
Originally Posted By: Clevy
Originally Posted By: jsfalls
All the sensors are telling the computer the engine is cold, and gives it a richer mixture. Some engines even have a cold start injector that does nothing but spray in extra fuel when first starting the engine when cold.



What engines are those that come with the extra injector for cold starts?


A lot of older GM engines with early multiport injection had a cold start injector, like late 80s F-Bodies.

Are you sure about that?

My '87 3.8 mpfi does not have a cold start injector, but rather uses the IAC (idle air control valve) to increase air to the to the intake via a pintle controlled by a stepper motor attached to the throttle body.
The ECU gets readings from the coolant temp sensor, which in turn adjusts the air flow via the IAC increasing idle (more air = higher idle/increased fuel demand). Once engine temp rises, ECU adjusts the IAC and idle rpm lowers.

IIRC, my previous F body Firebird 5.0 TPI had the same set up.

I once had an '88 Camry (3SFE) that utilized a cold start injector rather than an IAC set up. They were prone to get internally leaky, but super easy to change out. I miss that car! The 3SFE was by far the easiest car to work on... not all that powerful, but super reliable


Oops, it's not an injector, but a "cold start switch," p/n 19244930, on the intake. Not sure how it functions, but we have had people ask about them.

 

[SHOZ]

My Accent takes longer if it is really cold, single digits or below.

The FI pulse width can be controlled for a longer duration giving a richer mix by the ECU depending on the IAT signal.