cold starts
 

I cannot get the car to start well in any air temps less than in the high 60s or more like into the 70's. Anyone have any idea what the coolant temp map should look like? or maybe it's the cold primer map??? I'm lost. I have a streeported motor with stock injectors. The motor is fine...it's new...hot starts are perfect, great boost, compression etc...it's a Haltech thing and I can't figure it out at all!!

sorry..E6K

Hey,

You can try to enrich the fuel system more in the colder temp area in the COOLANT MAP and advance timing more in IGNITION COOL MAP in the colder temp area too... under vacuum of course.

Cold start is the most time consuming part of tuning because you only get one shot at it. Once the engine is warm you have to wait half a day to try it again. It'll take you a few shots to hit it. Here's what I do.

-Wait for the car to cool completely. Overnight is best.
-Get your laptop hooked up and ready. O2 sensor ready etc. You don't want to be scrambling around while the car is idling and warming up.
-Start the car. Let it try to idle on it's own. See what the a/d ratio is. Any engine will need an a/f ratio that is more rich when it is cold than when it is warm. To start shoot for something around 12:1. Maybe even richer. Right now we just want to get it to stay idling while it warms up.
-Have the Coolant Map called up when you start the car and work each highlighted bar as the engine warms up. You'll need to make raw adjustments to start to all of them. But once the engine begins to move through each bar you can fine tune them.
-As the engine warms and gets closer to operating temp you can take some fuel out and shoot for a leaner a/f ratio.
-The colder the engine the more rich it'll need to be. If it gets very cold where your at sub-11:1 may indeed be neccesary.
-You won't get it completely right the first or even second time. If you drive the car to work take your laptop and work the coolant map every chance you get while the engine is cold until you're happy with it.

That will most likely be what you need. Work on that first and then come back to after start enrichment. Once it'll idle up from cold to warm if you still have a problem with it firing then immediately dying you can add some fuel or duration to afterstart enrichment. Most likely you'll just need to add some duration. However this setting is usually pretty darn close if you started out with something like a Hitman base map.

fellas.....thanks a LOT for your responses....yeah, I've been trying like you suggested, looking at the coolant map each time I go to fire it up while cool..so I'll just keep trying for now and also with your other advice that was thrown in there....very helpful guys....thank you....hope it's not a dumb question (I'm not great with the EMS)...with my streeport and just boltons for mods....would you at least have a ballpark at what the bar heights might be in the cooler zones so I know whether or not I'm even in the right zone....cause the confusion is this...I do think I need more fuel like you're saying...but I get crazy backfiring when trying to start cold (only after I've tried starting more than ten times or so..then the backfiring might start)...obviously that's suggesting extra fuel is already there, but I think it's there because of the 15 failed cranks, and not because it's acutally tuned too rich....if that makes any sense lol....


Mark

I forgot to mention in my suggestions to make sure the idle is tuned correctly when fully warmed before begining to work on the correction maps. If you are lean at idle when the engine is warm you don't want to be chasing that with the correction maps.

The backfiring is most likely a lean mixture. Are you checking the a/f meter? Like I said look for something in the 11:1 range when very cold and then slowly lean it out as the temps come up.

If it won't fire on the first attempt you need to look at your primer and post start maps. Adjust the amount and duration until you're there. If you're not sure which way to go save your current setting and then start adding fuel in increments to see if it helps. If you don't make any progress you can always reload what you had and go back the other way. Always backup your work. The primer and the post start maps just kind of have to be done by feel.

ok cool man...yeah that's what I've been doing...making adjustments then going back to my baseline if I'm not happy..thanks bro!

I can tell you it is not linear.
It likes to take a big jump at right around the temps you mention - I think this is your problem.

It tends to like a big difference right around 50 or 60F or so.
Then it tapers off smoothly to full operating temps like around 180F.


-Ted

ahhhhh ok thanks Ted...I had suspeected that....I guess I automatically think that I need to try to keep it pretty linear, but it's now good to know not to worry to go for extreme difference....thanks man.....

Also, another hint...don't worry about running it way rich.
The engine can handle a lot of fuel, so it's best to err on the rich side.
If it's too lean, it will not run at all, or it'll surge like a bitch.


-Ted

ok thanks Ted...damnit, I'm having a crazy hard time with this...the car won't start at all right now....thanks for the help....maybe I'll try going very rich next?

hey Ted (or anyone else)....
I was just thinking as a quick fix....really my biggest headache here is getting my car to my shop (100miles away) who can hopefully sort this out for me...in the meantime as I try to deal with my car, I was thinking about an engine "block" (for lack of a better term) heater. I've never used one so I don't know anything about them ie how warm they can actually make your coolant....I was just thinking to avoid the frustration in the meantime....if I could have my coolant sitting at 70 F or warmer, it will start easily for me....I was checking one out...it's a magnetic kind that you can put anywhere you want....you think that would warm me from approx 50-55 F to 70 or so????

Mark

Yeah, interesting option, but it does sound like it'll work. :)


-Ted

cool...im gonna try that..thanks for your responses...