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Haltech cold start tuning

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Old Dec 1, 2009 | 09:07 PM
  #26  
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still suffering... any suggestions welcomed
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Old Dec 1, 2009 | 11:38 PM
  #27  
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From: Indiana
Originally Posted by j9fd3s
cold starting is just one of those things you have to spend a few hours playing with...

timing: the FSM says cranking is 5btdc, if its really cold you may need to take some out.
So, under the ignition crank map my advance is showing 27 degrees of advance...I should roll that back to 5 degrees?

My car almost refuses to start when it is cold.
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Old Dec 2, 2009 | 12:08 AM
  #28  
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weird. my car fires right the hell up.
mine shows 15 degree right all over across the board.
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Old Dec 2, 2009 | 07:24 AM
  #29  
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mines had 15, bdc told me to drop it to 5 or 6*
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Old Dec 2, 2009 | 09:49 AM
  #30  
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Yep drop it down. It'll depend upon the porting style (stock vs. high overlap bridgeport) and the compression ratio. A good place to start is 5* in my opinion.

B
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Old Dec 2, 2009 | 05:24 PM
  #31  
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That would maybe explain the cold start not going so hot
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Old Dec 2, 2009 | 08:12 PM
  #32  
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I recently installed a BAC and spent quite a bit of time tweaking things. I also dropped my ignition crank to around 6 or 7 degrees. It used to be over 15 (I didn't make the previous tune). My car has been starting and idling great, cold or warm! No excessive cranking. I've gotten my idle to around 12.5:1 ratios. It used to be terrible around 11:1. So far things are working out.

I've also read in the FSM that using a thinner oil can increase cranking speeds. Now that it's December and cold here in NY, I'm thinking of switching to 10w30. A quick crank speed could also help in start ups.
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Old Dec 6, 2009 | 09:37 PM
  #33  
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u still having cranking prob in mine after dropping cranking advance. seems like i have to play with the throttle to get it started. not really floor it but sorta open and close it a bit a few times.
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Old Dec 7, 2009 | 06:50 PM
  #34  
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From: cold
what kind of control does the E6K give over the BAC valve? I am looking through my E6X Halwin and it says that all the main BAC valve settings are only available in the E11?

with a large streetport I always had unacceptably slow cranking without a BAC valve. The BAC valve runs at 244hz according to the FD service highlights document, and the FD and FC valves are very similar in terms of the coil design. From the factory the FC BAC valve runs at about 95% duty during cranking to give extra air. The thermowax helps cold starts too. To elaborate:

A USDM spec FC has 4 additional sources of air during cranking and it sounds like most of the people in this thread have removed all of them. The first is the accelerated warmup system, and as we all know that's just overkill and should be removed. The second is the thermowax system, which opens the throttle plates during cold start and low water temps. The third is the bypass air port in the BAC valve that is adjustable by a screw. A similar bypass air port screw is under the TB elbow of the FD throttlebody, and on top of the non turbo FC dynamic chambers. The bypass air port is completely independent of BAC valve duty. With the BAC valve unplugged the bypass air port is still supplying idle air. I have actually pressurized the valve on a bench to confirm this.

The 4th source of bypass air is the cycling of the BAC valve itself. With the AFM removed, the BAC valve doesn't even need a hose or anything. You can put a filter on top of it or just open it to atmosphere if you don't care much. You can skip the coolant hose as well unless you are in a very cold area and are concerned about the valve freezing up. The BAC valve duty is adjustable with the "post start duty" "min cold duty" and "cold open duty" settings in the Haltech. There is also closed loop control logic for it by setting a target idle speed and setting PID coefficients, just like Haltech boost control.

So when you reinstall the BAC valve on an FC, you are actually supplying two sources of additional air during cranking.

Another thing to consider is that a lot of aftermarket fuel pressure regulators don't hold fuel pressure like the stock one. That especially hurts cold starting. I have noticed that on my Aeromotive regulator.
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Old Dec 9, 2009 | 08:26 AM
  #35  
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way to take this miles off topic.. so far where its at is my E6X isnt producing a priming pulse at startup, please read the previous posts
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Old Dec 12, 2009 | 11:07 AM
  #36  
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From: atlanta ga
Originally Posted by TalkSick
way to take this miles off topic.. so far where its at is my E6X isnt producing a priming pulse at startup, please read the previous posts
not really. its spot on topic. the fact that my cold start cranking is perfect, yet hot start is a mess unless i press the throttle in a lil bit... help tons.


also... messing with crank timing map produces no change in results.
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