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AEM EMS Cold Start

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Old Feb 15, 2005 | 12:34 PM
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Default AEM EMS Cold Start

I have a hell of a time starting the car in cold weather or when I let it sit for awhile. I am guessing it has to do with the start. Has anyone figured out the best way to get around this with the EMS?
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Old Feb 15, 2005 | 12:48 PM
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The last sentence of this post by UL may be of interest to you:
https://www.s2ki.com/forums/index.php?showt...dpost&p=5103822
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Old Feb 15, 2005 | 10:08 PM
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I've been playing with the initial pulse value and the extra fuel tables (based on coolant temp). Right now, my values are roughly double AEM values below 35-45 degrees. It seems to have greatly helped.

tim
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Old Feb 16, 2005 | 06:11 AM
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Lots more fuel for the fuel pulse and lots more enrichment for cold coolant temperatures otherwise it will start and then die. It is also common to have a battery drain problem too. With an ammeter check the current drain from the battery with everything switched off. There are a few other tricks too but I would have to be at your car to try those.
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Old Feb 16, 2005 | 08:25 AM
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Originally Posted by gilbertg' date='Feb 16 2005, 10:11 AM
"Lots more fuel for the fuel pulse and lots more enrichment..."
I'm not trying to hijack this post, but I'm having similar issues. Only difference is the car won't "start and then shutoff." It just doesn't start period. When I have my problems, the car just doesn't start and appears to have a dead battery. When the car does start (90% of the time), I have to let it idle for about 3 minutes. If I don't, and i give it any gas, it seems to choke. I have to ride the clutch to get it moving if I don't have time to let it idle. If I don't ride the clutch, the car will choke and shutoff, then I can't start it for 2 hours or so...and it requires a jump start. I'm just trying to see if I'm in the same boat, or if I'm in a completely different EMS problem. If I'm having related problems, I"ll try what the people above have mentioned and see if that helps.

Thanks,
Dave
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Old Feb 16, 2005 | 09:27 AM
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Originally Posted by bgbfflochp' date='Feb 16 2005, 12:25 PM
When I have my problems, the car just doesn't start and appears to have a dead battery. When the car does start (90% of the time), I have to let it idle for about 3 minutes.
Do you have a wideband O2 sensor? If so what kind? I have a constant power drain to the point that if I leave my car for 2 days it will not start. When testing the cold weather cranking you need to use a battery charger to help prevent the low battery voltage from being a problem until you get the fuel figured out. The car running badly when cold is an coolant temp/air temp enrichment problem and probably some accel fuel issues where it's running too lean or too rich when you touch the throttle. The wideband O2 will tell you which.
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Old Feb 16, 2005 | 09:57 AM
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Originally Posted by bgbfflochp' date='Feb 16 2005, 12:25 PM
If I don't ride the clutch, the car will choke and shutoff, then I can't start it for 2 hours or so...and it requires a jump start.
This is fouled plugs. General note with the EMS, if you stall it you're in for trouble. I did it once in the drive thru lane and had to push the car out of the way Usually switching the car off, leave it for a few seconds and then start again usually works, but in your case it looks like there are a few other things wrong. In general does the car start well once it's warm, i.e. if you go to a gas station, fill it up and the start it does it start fine?
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Old Feb 16, 2005 | 10:19 AM
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Gilbert, so do you just sit there and keep increasing the fuel pulse and fuel until it fires right up? Won't that foul the plugs eventually?
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Old Feb 16, 2005 | 10:35 AM
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what's the serial# from these ems's. aem had cold start problems with the early ones.
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Old Feb 16, 2005 | 10:32 PM
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pm me with your e-mail address. I'll send you a copy of my map. It will be easy to see the changes I have made to the startup tables with the compare feature. The initial crank pulse has been greatly increased as has the extra fuel the coolant enrichment table adds. I think I also extended the initial start extra time. I can easily start in temperatures down into the 15-20 degree range now. Sometimes the battery injector offset values are off if you're running aftermarket injectors. I believe those will also dramatically affect cold start. Good luck.

Tim
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