24x Ls1 ms3x no start

rockstar4556 · Post by **rockstar4556** » Mon Nov 13, 2017 7:57 pm

Just got it reading rpm signal but still cant get it to fire up completely. It starts to fire but gets choppy an quits. If anyone can peep at my tune/short log maybe point me in the right direction it would really be appreciated.I did give it throttle towards the end of the log. 5.3, Siemens deka 80lbs inectors, on3, ls1 intake

Matt Cramer · Post by **Matt Cramer** » Tue Nov 14, 2017 7:52 am

The most pressing issue appears to be a need to tune the cranking pulse width. Beyond that:

Battery voltage drops a lot while cranking. Might want to check that.

Your MAT sensor appears to be unplugged.

Any reason it's running batch fire fuel settings with the MS3X? LS1 mode will support full sequential without any trouble.

What sort of coils are you running? That's a lot of dwell.

No idle valve?

billr · Post by **billr** » Tue Nov 14, 2017 9:52 am

Add to the above...

With 8 squirts/cycle and large injectors, the DT better be near-perfect. Is you value of 1.3 msec a measured value? Did you flow all the injectors to get the best average for rate and DT?

I gotta ask... have your verified spark timing with a simple (non dial-back) light? Have you verified it for all cylinders, or at least tried "wasted COP"?

rockstar4556 · Post by **rockstar4556** » Wed Nov 15, 2017 4:40 am

Figured out what it was, guess i had to many brews when wiring cause I didnt wire my coils corectly on my ms3x. Fired right up after that runs super rich so ill have to adjust that once i get my downpipe 02 welded on. I was under the impression that ms didnt support 3 wire idle valves so i never wired it

Post by **jsmcortina** » Wed Nov 15, 2017 4:56 am

rockstar4556 wrote:I was under the impression that ms didnt support 3 wire idle valves so i never wired it

2- and 3- wire PWM idle valves are supported.
4- and 6- wire stepper idle valves are supported.

James

Matt Cramer · Post by **Matt Cramer** » Wed Nov 15, 2017 7:12 am

rockstar4556 wrote:Figured out what it was, guess i had to many brews when wiring cause I didnt wire my coils corectly on my ms3x. Fired right up after that runs super rich so ill have to adjust that once i get my downpipe 02 welded on. I was under the impression that ms didnt support 3 wire idle valves so i never wired it

How exactly did an LSx end up with a three wire idle valve?

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24x Ls1 ms3x no start

24x Ls1 ms3x no start

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