1-2nd shift delay

[281MERC]

my tranny has been acting up lately, under wot the 1st to 2nd shift is delayed and the engine pings off the rev limiter a few times then finally shifts into 2nd and starts pulling again? this problem has slowly been getting worse but doesnt always occur. the 2-3 shift seems fine and i have done a tranny flush and filter change before these symptoms started to occur. i am using amsoil synthetic universal ATF. whats up??? ....please note mods in signature V

[ctrlraven]

Have you recently put on smaller tires than stock on the rear? If you have then just bump the rev limiter up 100-200 rpms and problem should be fixed.

I had the same issue when I changed from 255/55-18 to 265/50-18 cause it was a smaller diameter, was advised by an old member of the site to bump the rev limiter and 1-2 shift was perfect then.

[281MERC]

Have you recently put on smaller tires than stock on the rear? If you have then just bump the rev limiter up 100-200 rpms and problem should be fixed.

I had the same issue when I changed from 255/55-18 to 265/50-18 cause it was a smaller diameter, was advised by an old member of the site to bump the rev limiter and 1-2 shift was perfect then.

im running the stock 245 55s, they are pretty bald but that would cause an early shift if anything.

[281MERC]

my rev limiter is set at 6600 rpm with lidio's tune. i shouldnt even come close to that, lidios tune should shift around 6100 right???

[TooManyFords]

Step 1. Set the rev limiter to 7500.
Step 2. Profit!

[ctrlraven]

Under WOT it will take the rpms all the way to the rev limiter to shift. Mine has always done it that way. If the user end adjustment for the Revs in Drive is unlocked bump it to 6700 and give it a try.

[281MERC]

Under WOT it will take the rpms all the way to the rev limiter to shift. Mine has always done it that way. If the user end adjustment for the Revs in Drive is unlocked bump it to 6700 and give it a try.

yes my tune is unlocked and i have fiddled with it in the past. i actually used to have it set at 6300rpm just to be on the safe side and it never bounced off the rev limiter. before i put the car away i had everything set to the defaults except for the 4.10 gear setting and a bump up in idle to 666rpm and the problem still occurs. i want the tranny to shift at the rpm lidio designed it to in his tune. raising the rev limiter is just a quick fix in my opinion. i bet im gona have some costly repairs this spring :mad: im wondering if its because of the tune or even the flush i did.

[281MERC]

let me know what ya guys think.
thanks

[RF Overlord]

a bump up in idle to 666rpmThere's your problem...bad juju.

[babbage]

let me know what ya guys think.
thanks
I think in the XCAL you can tell it to lower the mph for the WOT 1-2 shift by 3mph and that should fix it without messing with rev limit.
Its the cold air that's causing your engine to rev up faster, by the time the PCM commands the shift you are hitting rev limiter.
In summer you wont have this "problem"

[Blackened300a]

im running the stock 245 55s, they are pretty bald but that would cause an early shift if anything.

Are you doing a WOT launch and spinning off the line when it happens? Or are you hitting the limiter all the time?

[ctrlraven]

I've only seen idle numbers in increments of 25 and 50. Picking 666 def is bad juju.

[281MERC]

I think in the XCAL you can tell it to lower the mph for the WOT 1-2 shift by 3mph and that should fix it without messing with rev limit.
Its the cold air that's causing your engine to rev up faster, by the time the PCM commands the shift you are hitting rev limiter.
In summer you wont have this "problem"

i think this is the best explanation yet since the problem started near the end of the summer and the worse time it happend was on a cold night. i raced my buddys stock 07 silverado MAX LTZ 6.0L with a k&N fipk. we were neck n neck off the line up until the first shift where i started pinging off the rev limiter for literally a full second and he pulled away and i didnt catch up to him til around 140km/h:mad:
......so if i took off the underdrive pullys and intake i wouldnt have this problem in cold temp's????

[281MERC]

I've only seen idle numbers in increments of 25 and 50. Picking 666 def is bad juju.

correct, lidios tune can be adjusted in increments of 50 with a default setting of 516 RPM. 516 + 150 = the number of the beast!

[281MERC]

Are you doing a WOT launch and spinning off the line when it happens? Or are you hitting the limiter all the time?
under wide open throttle it has happend with and without wheelspin

[justbob]

Its the cold air that's causing your engine to rev up faster, by the time the PCM commands the shift you are hitting rev limiter.
In summer you wont have this "problem"


This is probably your answer ^^^. Mine has been banging the rev limiter all winter. Simply can't react to how fast the tires are spinnin. I can slam thru 1st in one second, bang the limiter and off into 2nd for another 2-3 seconds before I let off and only move 2 1/2 feet... Or anytime I go WOT I should say.

[babbage]

i think this is the best explanation yet since the problem started near the end of the summer and the worse time it happend was on a cold night. i raced my buddys stock 07 silverado MAX LTZ 6.0L with a k&N fipk. we were neck n neck off the line up until the first shift where i started pinging off the rev limiter for literally a full second and he pulled away and i didnt catch up to him til around 140km/h:mad:
......so if i took off the underdrive pullys and intake i wouldnt have this problem in cold temp's????

No silly, don't take off your mods. Modify the tune, for wot shift on the 1-2 shift lower the mph by 3. Minus three. I can do this to my tune.. on my xcal2. You should be able to also.

[281MERC]

No silly, don't take off your mods. Modify the tune, for wot shift on the 1-2 shift lower the mph by 3. Minus three. I can do this to my tune.. on my xcal2. You should be able to also.

haha...dont worry wasnt going to, i was just giving an example 'cause you said something about the engine reving up to quick. and yes i can adjust shift mph but i shouldnt need to adjust it till the fall when its cold again.......if this is the real reason why its happening.

[babbage]

haha...dont worry wasnt going to, i was just giving an example 'cause you said something about the engine reving up to quick. and yes i can adjust shift mph but i shouldnt need to adjust it till the fall when its cold again.......if this is the real reason why its happening.

;) It's the real reason. Isn't it cold now? It sure is cold in NY where I am..

4v loves the cold air and does in fact rev up faster in cold air so the symptom you are seeing is normal with a tune. Factory the shift points are well away from the limiter so you'd never have it happen.

If you lower the shift MPH for the 1-2 shift at WOT this will give the PCM a head start and you should no longer hit the rev limiter. When its warm again you can remove it that from the SCT on device adjustability. Ask lido or whoever did your tune if you don't believe me.

The upside is you know your MM is running good if you have that kind of problem. :burnout:

[281MERC]

;) It's the real reason. Isn't it cold now? It sure is cold in NY where I am..

4v loves the cold air and does in fact rev up faster in cold air so the symptom you are seeing is normal with a tune. Factory the shift points are well away from the limiter so you'd never have it happen.

If you lower the shift MPH for the 1-2 shift at WOT this will give the PCM a head start and you should no longer hit the rev limiter. When its warm again you can remove it that from the SCT on device adjustability. Ask lido or whoever did your tune if you don't believe me.

The upside is you know your MM is running good if you have that kind of problem. :burnout:
ya it was -15 today, but my car has been parked since november;). so if your right i should have no problems when i take it out in the spring and i won't need to adjust my tune:)