Cold Start setting for 1.6L and 460cc RX7 Injectors... - Miata Turbo Forum - Boost cars, acquire cats.

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Old 01-20-2008, 05:24 PM   #1
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Default Cold Start setting for 1.6L and 460cc RX7 Injectors...

Hey guys... It's a ripe 23 degress outside and low and behold the miata doesn't want to start. I have been playing with my crankin PW for about an hour and Paul even came over to give me a hand. Still no dice. Does anyone have a good cranking/prime table for the RX7 460's along with any tips to help me get this dialed in. I have read a couple of posts on here and nothing sugested really seems to work. Also what setting in the configurator should i have set for the idle controll valve?
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Old 01-20-2008, 06:11 PM   #2
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Use PWM for the IAC in configurator.

I too had trouble starting my car today when it dropped to 5*. Had to add fuel to those cells in cranking settings. I was at 5.1 ms and ended up at 5.8 at 0* and 5.4 at 10*. That's for 550s on a 1.8 though. You should be able to use Braineacks current settings. I think he posted them in one of the recent coldstart threads.

I knew i wasn't running enough fuel because it wasn't backfiring or anything, and the numbers were low compared to what they should be compared to the known good values i had for warmer temps.
You should be able to start low and work your way up until it starts. If the temp is between two of the cells you can raise the fuel in both of them because it averages the two cells according to the temp, so it's slightly weighted either way. If you added too much fuel you could have flooded it and then it wouldn't start even if your settings were right. Might want to pull the plugs and dry them out if you need the car in a hurry.
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Old 01-20-2008, 06:36 PM   #3
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i put values in there i thought would start you. has it yet to start at all? are you flooded like whoa now?
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Old 01-20-2008, 06:51 PM   #4
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Nah it was fine up until it hit 23 degress today. Yesterday i drove it around a bit but didnt do any real tuning becouse my wideband wasn't programed to output 0-5v and only sending a narrowband signal. I went to start it today and it wouldnt, then it gave out some crazy backfire. I tried lowering the Pw's with no dice. I also found a table you posted for someone here. https://www.miataturbo.net/forum/sho...82&postcount=8 That didnt do any better either. I had the compressor out and cleared my cylinders and plugs about 10 times. Everything seems to be fine with the ms. There was only one strange thing yesterday. My idle valve seemed to be out of control. What ever i would do in megatune it would just hold the rpms at like 2500. I just wound up unplugging it and my idle went down to 950 or so.
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Old 01-21-2008, 11:51 AM   #5
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yeah after it backfires its already way too rich. so the plugs are flooded. and youd have to wait 20-30mins or clean them off before restarting will work again, even with 0ms PW.
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Old 01-21-2008, 08:23 PM   #6
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i got it. Another bitter cold day and my car starts fine now. My plugs got fouled out. All i needed was a new set and bingo. I'm using a cranking table that is a cross between the diy map and braineack's one i linked in my last post.
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Old 01-21-2008, 08:28 PM   #7
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Take a screenshot, crop it down, host it with tinypic.com, and post it here. Anything to help keep the newbs at bay.
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Old 01-21-2008, 10:21 PM   #8
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Let me let the car sit overnight and fully cool down. If it starts fine then i will post what i have. I went out about 3 times and tried to start the car. Everything seems good. My coolant temps have only gotten down to about 60 degrees and it is about 20 out right now so you can see how patient i am. LOL I also went on about 4 20 minute datalog runs using the ve anaylzer after each. The car seems to be driving alot better however i have a really bouncy tach needle and the car is jerky at about 4k. I will have to read what thats all about. Im hoping a ground or two will solve that.
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Old 01-22-2008, 10:32 PM   #9
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Just a quick update i am successfully running the PW's that Braineak had outlined in the post I linked above. They are now tested for RX7 460cc injectors down to 15 degrees Fahrenheit.
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