chevrolet02z28

OK heres the basics... i have a 2002 camaro z28.. a4 with 373s, auburn posi, slp lm catback, and a hypertech for my speedometer...... my problem has been occuring on a rather rare basis but finally figured out how to get it to do what i want and ****..

ok so when im crusing maybe at about 40 mph.... around 16 or 1700 rpms i think... if i get on it half throttle.. it downshifts and the rpms shoot up to about 4000.... upon keeping my foot on the throtle at the same spot n not moving it an inch.... it shifts off the 4000 down to maybe 2800.... (mind u im still on the gas the same) when it gets to about 3000.. it just levels off like just a blahhhhhhhhhhhhhhhhhh.... then a few seconds later it shifts...

i thought maybe the programmer maybe had something to do with it so i removed all the settings.... and it just didnt shift right cause the computer resets it down to 273s.... so i then just went in n ot touching ne thing but the rear axle ratio... and it still does it..... but i need my speedomoter to b e correct and for the comp to know it has the 373s..........

WTF COULD IT BE! is my trans bout to take a ****?


OK SO I JUST TALKED TO MY UNCLE WHOS A MECHANIC...

His thought on this is that its just transmission lag... and that maybe one of the celonoids are just held up from ****....? any thought? ideas.... he sems to think that a tranny flush should do the trick and clean sum of the funk in there....

and does any one know if the pan gasket is reusable or not?

performabuilt

iTrader: (25)

I still tend to think you may have a tuning issue, But I am not a tuner so cannot give you any experinced advise in this area, But I think it may be moe complicated than just changing the ratio perhaps there may need to be some changes in the shift mph and the RPM I know the RPM and MPH would change with the gear ratio and I know you have to change both to alter shift points

radz282003

iTrader: (1)

Do you have a stall in there? If so, maybe it's the TM. I found that if I didn't have mine deleted, under larger throttle inputs, the lag between shifts was very long.

I hope you can work the problem out either way.

midnight_effect

iTrader: (4)

im not a transmission expert by any means, and depending on the mileage on your tranny i personally have an 02 z28 a4 with 90k on the tranny and have been seriously warned against doing any type of flushing, to avoid screwing up the valvebody. from what im told alot of times the flush blows away **** in the valvebody that is holding things together.

chevrolet02z28

hummmm all seems reasonable but still dont know what the f to do.... liekm i said with the tuning... i took the programmer off it completely.. so it thought i had the 273s.... and it just didnt shift right at all it was so much slower... didnt have that umph to it... i know with the shift points on it... through my understanding that will only change the full throttle top end i thought? the why hypertech explained it... where as if stock it might shift around 5800.. wheras if u tunie it to hold a little longer it will put it up to 6000 or so on if u change the rev limiter....

i did a flush like ithink about 38,000 miles... and i know at certant times the shift where harder... upon doing it it felt alot smoother in the shifts... and the manual in the book states to do it i think every 15000 miles under daily driver conditions cold weather on some other stuff... and i just turned 52000.. now last time i did it though he just flushed .. i figured this time ide take it upon myself and just do it right and buy the filter kit for it from gm.... figured 30 bucks w.e.. might as well?

and no i dont have a stall in the car..... i donmt know wtf to do.... hes been a mecahnic for like 25 years... at a very reputable shop... not to mention hes my uncle... sooo hopefully his opinion on a flush will help it...... liek hes never been wrong with alot of craps hes told me soo... gonna keep my fingers crossed and hopefully the flush doesnt blow nothing away in the valve body as u stated.... he saiud maybe next week so ill keep posted if it helps....

FLT

iTrader: (1)

I think that you have an issue with your programmer. I would get your factory computer reflashed with the proper ratio and tire size. There are many places that can do it for you. Most use hp tuners or ls1 edit. Just a thought. Vince

98Camarod

iTrader: (43)

I'd think you would have to have the proper gear ratio programmed for it to shift correctly. I'm pretty sure that the tranny shifts off of mph. It's all electronically controlled. I could be wrong.

chevrolet02z28

upon posting about the shifts being weird at certain RPMs.. whenever it is shifting now at lowers RPMs it seems to have a lag. HIgher RPMs dont seem to really be affected. Any new suggestions?

performabuilt

iTrader: (25)

Do you have it programed for the proper gear ratio right now ?

Ragtop 99

iTrader: (7)

I'd bet it is a computer issue. HPP3 doesn't always get the shift points right when you change gear ratios. Go to someone with HPT or EFI Live and have them look at your tables.

chevrolet02z28

yeah right now its programmed for the 373s.... just running like *** though.... my uncle seems to think it might be a celenoid that junked up.... i dono.... i took it out for a long drive today since its been liek so damn cold here.... and the shifting of it seemed to feel a bit better but it still has the like cut off at 3000rpm... i dont even know who the hell would have hpt or efi live?.... is that something a dealership would have? and ive had the rear done for months now n never seemed to have this problem.. i put em in in about august... n now that winter has come ive noticed it... u think maybe whether is affecting the over all performance? beiing that its so much thicker and i only drive it like a mile and a half to work and like 2 and a half miles to my gfs in such cold whether?

i just dont seem to understand why all of a sudden its acting up..... it was fine before....

chevrolet02z28

OK so heres the update.... My buddy i havnt talked to in awhile i ran into.. and coincidently works for GM.... sooo he put in the word at the shop and talked ot the tech.... gave him my car for a day.... and heres what was done... he had to call up and get a new code so the car that was originally tuned for 273s now is put in as 373s... And he too the info n **** out of a vette and tuned it into my car.... he said it will run better and the tech dude did it to his 89 iroc with 02 ss camaro tuning on it... (and that it IS compatible with my car) soo i said as long as it dont F ne thing up ok... so he did it... i got it back...and the thing drives beter then ever.... no lag up in the transmission thing shifts perfect ever time.. ive trieds numerous time to get it to hang up at 3000 rpms... and havnt gotten it yet...

Gilbert@Ace Racing

Glad to see it was a tune issue and nothing else.

This thread could serve as a very useful sticky for reference in the future!

g

chevrolet02z28

Yeah although jsut flashing the computer the tech at g, said it would prbably come back.... so the only way to avoiud it was to get a new like DS code or some crap