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Thread: new cam idle issues

  1. #1

    new cam idle issues

    I just finished installing a 228/230 cam and have started trying to get it to crank and idle. the problem I'm having is that I have to hold to gas pedal down about 40-50% to get it to start, then have to feather it. after a minute it'll settle @ the 750 rpm. Any advice is much appreciated.
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  2. #2
    i should have continued reading bigmikes thread on getting idle corrected. i'm taking notes and will try again, but if anyone has something to offer i'm all eyes.

  3. #3
    well with a little work I have somehow managed to get quicker starts and a fair idle. I have settled at 850 rpms for now. but I have been unable to get the idle to pick up @ 850 on the way down? when I hit the throttle up to 1k - 1.5k and let it go the idle falls to 500 rpms almost stalling and then rises to the 850 mark. I know someone has run into this before. its got to be in the "adaptives" somewhere. anyone got any ideas. I was hoping to start ve and maf tomorrow.

  4. #4
    Tuning Addict 5FDP's Avatar
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    I didn't look at the log or file but you will want to get the MAF/VVE somewhat done before going to crazy with idle changes.

    If the airflow model is still all over the place you are going to be fighting that when doing idle corrections.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  5. #5
    so do you think it would be safe to hook up the wideband and drive it? whats first maf or ve?

  6. #6
    Tuning Addict 5FDP's Avatar
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    If the idle drop off is the only problem, consider yourself lucky.

    It's not like it's going to explode or anything. The only way to get things right is to start driving it.

    Pick whichever you want to do first. Majority do the MAF first on the newer computers.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  7. #7
    Tuner in Training 1278342005's Avatar
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    Quote Originally Posted by 5FDP View Post
    If the idle drop off is the only problem, consider yourself lucky.

    It's not like it's going to explode or anything. The only way to get things right is to start driving it.

    Pick whichever you want to do first. Majority do the MAF first on the newer computers.
    Wouldn't he want to add to the base running airflow and move the RPM up to roughly 800-850? Also he should add to startup airflow and move the under and over up to about 1.5 seconds.

  8. #8
    Tuner in Training 1278342005's Avatar
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    I just took a look at your tune. Your base running airflow is holy crap out of sorts IMO. Also your startup airflow can be added to to make things start a little easier. As someone that is starting off, move in small percentages. Start at your avg temp and add 5% at a time until it will crack off and fire relatively quickly. What are the mods other than the cam? I assume bolt ons?

  9. #9
    thanks for the replies. this is a truck 4.8 228/230 cam,valve springs, airaid intake tube only, k&n air filter in stock box, and a dynamax muffler. I started over and only adjusted airflow in startup and idle base. the thing cranks right up perfectly cold. then as it switches over to run mode the loping gets more pronounced, but stays running. I wouldn't mind taking some lope out of it. after it warms up i'll gas it up to 1k-5k and let off and it will drop to 500, act like it wants to stall, then picks up and steadies @ 850. I don't think i'm doing to bad for first attempt @ cam, springs, and tuning. I have an idea of what needs to be done, its just finding the dang parameter in the software. today i'm going to turn off all adaptives and get the base idle and figure out warm slow start.
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  10. #10
    its getting better the truck will stay running in p/n and drive with ac on. as far as the idle returning= I added airflow in the min. airflow table in the trouble areas. I assume until I get the fuel correct that's the quick fix. my next question- Is it better to run more timing and less air OR less timing and more air, as far as the idle goes? right now ive got 18 degrees timing and 14 grams of min. airflow. its fairly steady at 850 rpms with very little blade movement.

  11. #11
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    I personally find I have better success running enough air so it will idle comfortably on 10-13 degrees warm. then when its cold or it stumbles and tries to recover it can add timing up to 20 plus degrees which will be effective.

  12. #12
    thanks for replying. I had some success getting the truck idling smoothly. just as you stated I used airflow. I have since calibrated the maf and moved to sd. this sd is kicking my butt. it would not start to begin with. then I copied and pasted to the vve a couple times. then I got it to run at idle p/n and ac. but then I went to drive it and it was stumbling all over the place, so I parked it. I believe high iat is causing problems. I'm going to let it cool down and try again. this cam shows odd reads on every crank, one time it will show rich ill make adjustments then the next idle itll swing the other way what???? maybe fuel left in exhaust idk