2014 Ram 5.7 idle surge

Hi all,
my first post on the forum so be gentle....

I live up in Canada, and own a 2014 Ram 1500, 5.7. I installed an MMX NSR cam (115 LSA) and have been working with my tuner (email tunes) who's been great in getting it dialed in. The only area I'm struggling with is the initial idle, after the pickup has been standing all night. The engine starts, and then starts surging a few times and either dies, or makes it out of that loop ok. I've attached a copy of the log when it makes it out ok, from what I can tell, I think she's running lean on startup and then, by the time the short term fuel corrections come in, it settled out. I'm also wondering if the PID loop (no idea where to tune that) isn't opening the throttle too much, too soon, dumping all that air into the manifold?


Any thoughts/comments appreciated,

Cheers.

I do believe that lean spot you are seeing is because your wideband hasn't actually started recording yet (not through the warmup cycle) What I think you may need is to bump up the numbers in the Desired Airflow startup (35020) maybe add 10-15%. It's firing up then not actually getting enough air for the transition from startup.

Hi,
firstly thanks for looking over the file. I didn't have a wide bandhooked up, but I'm assuming there's a few seconds in there for sensor warm-up. In the 35020 table, my column axis is listed as "Alcohol Composition %". I'm assuming this is an error and should read seconds?

Attachment 103178


Thanks,

Quote:

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Originally Posted by sPHYNX

Hi,
firstly thanks for looking over the file. I didn't have a wide bandhooked up, but I'm assuming there's a few seconds in there for sensor warm-up. In the 35020 table, my column axis is listed as "Alcohol Composition %". I'm assuming this is an error and should read seconds?

Attachment 103178


Thanks,

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You're welome! Those numbers are really low. Do you have the stock tune to reference? Typically around the range in the referenced attached. Those are bumped up some from the stock numbers about 10-15%

Quote:

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Originally Posted by McCloud

You're welome! Those numbers are really low. Do you have the stock tune to reference? Typically around the range in the referenced attached. Those are bumped up some from the stock numbers about 10-15%

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Hi,
the stock numbers were bumped up, but only from "50.5 Alcohol Composition". I can try adding 10% across the range. Could you confirm what that top column is, is it seconds or counts?

There also another table in here called "multi" (35022). Any idea what that table does?


Attachment 103182
Thanks again,

I'm still learning the tables within this PCM but the mult 35022 is tied to 35020. I assume that is why your numbers in 35020 are lower as the mult is higher. I do beleive that it is tied to flex fuel so that could be tied to alchol comp and the Mult adds based on counts/time.

I had the same startup issue you had and based on what I could find this change was the solution and it did work. I went accross the range to keep things consistent.

Hi, just some feedback. I multiplied everything by 10% and made a few other minor changes. Idles like a champ now.

Thanks again,

Awesome! Glad you got it worked out.

Looks like my ghost has come back....With the added air, as it's getting cooler again, I got this RPM surge again. Looking strictly at the data, would those smarter than I am say it's an air or fuel issue? Only does it on cold start, the next start is good....

Thanks in advance,

I tune dodge. Message me if you'd like to try a different tuner.

Quote:

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Originally Posted by luciddeath

I tune dodge. Message me if you'd like to try a different tuner.

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Hi, thanks for the offer. Would you know if the column axis is correctly labelled?

Thanks,

Top label can be anyway you like, just depends how it's tuned basically. The multiplier adjusts airflow by crank i believe, i usually change it entirely from stock especially on cammed setups. I always go by lb/min so i can't be much help off the top of my head from lb/h

Need to see the tune, but I always use the multiplier to my advantage, start high and go low and add a bit to startup airflow so it doesn't go too low.
Looking at the log as its missing a lot, it seems to be reading 0% alcohol so i assume they set stoich to something like 10.2afr.. or around .0980 air to fuel.. there are so many things that could be causing the surge, i would let someone with more experience tackle it but good luck brother

No worries, and I appreciate the input.

Cheers,

Fuel, spark, air...all needs adjustment. Post the file.

Hi,
I know I'm helping myself but out of respect for the "email tuner" I'd prefer to not post the tune. I've attached a quick log I ran this morning, the biggest issue I'm trying to resolve and find out is what controls throttle opening from 4 seconds to 15 seconds? Everything works great, until around 4 seconds when it looks like the throttle is working to open to increase RPM (and the engine boggs down) while the spark is retarding to prevent a stall. I've tried advancing the spark but then get that cyclic rpm. Hopefully there's just something obvious I'm missing here?

Can't rule out fuel on a cold start without a preheated O2 sensor. In its absence, the file would work to infer what the problem is. So...not enough information to diagnose.

Hi all, thanks for al the tips and advice. I think I've got this nailed down now. I increased the rear O2 sensor delay to keep it in closed loop longer, removed almost all the PID for throttle torque control, especially the integral, elevated the idle speed slightly and decreased the VE around the idle.



Thanks again,