mrvedit

First, I'm honestly sorry that you are still having the same problem. I would have been happy to send you the $5 if it had been the PCM.

As I answered to ninetyeightbird above, and as mentioned in the other posts today, a stock tune with a high stall converter will have this problem, largely because a higher-than-stock stall converter will have a bit more slippage.

My guess is that your converter recently started to slip even more, with the result that your previous tune no longer shifted at WOT. I don't know enough about converters to say whether/how they can slip more; perhaps someone else can state whether that is possible. (Since a converter can fail, I assume there must a state between perfect and failed.)

Black98T/A

iTrader: (5)

Well everything else works with this stock PCM. Yes I have an LS6 crate engine, headers, converter, no cats, air and egr and yes my SES light is on but it starts right up, runs, drives, and shifts fine except of course the WOT upshift. I also already spoke with a reputable tuner... Geoff Skorupa from Next Level Performance(who also installed my engine) he put a scanner on it and we went for a drive and also narrowed it down to the pcm not commanding the shift...I haven't spoken to him since though.

Black98T/A

iTrader: (5)

OK so youre saying my stock converter started to slip which originally caused this problem..then when I had the new converter(which is only a 2600 stall) installed it still wouldn't shift..then I send my pcm to get tuned for the converter and still no upshift...I then try a stock pcm and still no upshift. I understand it's possible but how many LS1's with converters even with higher stalls than mine and stock tunes are shifting at WOT? The majority right? I have a mild converter and tune and it's not shifting
This is what I'm being told
Transmission builder"I'm 100% positive it's not the trans
Tuner"I'm 100% positive it's not the tune"

edub80

iTrader: (2)

It's in the tune... go to a tuner and get your shift points changed.... its been said alot in this thread

Black98T/A

iTrader: (5)

What's a different tuner going to do that Keith at PCMforless can't do? Hes done thousands of tunes and I think he pretty much knows what he's doing but if there's something I can tell him let me know. I just paid him for a retune and to fix this prohlem and before I pay someone else I'm sending it back to him.

mrvedit

I would suggest asking him to reduce the WOT upshift speeds by a few mph.
If you are comfortable with it, I would also increase the redline by 100 or 200 rpm.
That will likely take care of it for you. If your tuner is using HP Tuners, kindly ask him to send you the tune file too. In the unlikely case the problem still isn't fixed, you could then post the tune file for more feedback.

Black98T/A

iTrader: (5)

I told him t reduce the WOT speeds a few mph last time...he told me he did. Let's get off it being the tune for a second since it's not shifting with 3 different tunes(original tune, retune, and stock tune) I just spoke with Mario who has a race shop who I got the used pcm from he originally said like others and my tuner it could be a driver inside the pcm and now since it's still doing it with his pcm which was working fine he said it's more then likely the check ball in the valve body, which according to him won't make the computer command the shift if there's a problem which is what I was also told from another trans guy. Like I said in post #15 I originally had a transgo HD2 shift kit installed a few years ago...the WOT shifted fine up until last year. When he rebuilt the trans he re used the shift kit. He said that was ok and would save me the money on a new shift kit which was not needed. I asked the builder if that could be the problem(when I was told by the other trans guy) and he said no because the computer is not commanding the shift and it's not a trans problem so which is it?

mrvedit

The PCM has very little information about the trans, only what gear the selector is in, the engine rpm, the output speed from the VSS and the trans temperature.

I don't see how a check ball could change the upshift command, but I'm no trans expert. Replacing the separator plate and all the check ***** is not a big deal and does not require removing the trans. I just hope you solve this soon for your sake.

Black98T/A

iTrader: (5)

This is what I need to confirm, if an internal trans problem can cause the computer not to give the upshift command. The builder is telling me if the PCM isn't getting the command it's a PCM or tune problem as is another tech with a scanner. Others are telling me even though the computer isn't getting the command it can still be the seperator plate and check ball. Before I take it back to the trans shop and try and convince him to drop the pan can anyone confirm this?

Black98T/A

iTrader: (5)

What is your opinion on this problem possibly being the separator plate and or check ball in the valve body?

Black98T/A

iTrader: (5)

Spoke with my transmission builder again today I told him I tried another PCM he said there's no way a loose check ball or enlarged separator plate hole will cause the computer not to command the wot upshift and he's still 100% positive it's not the trans.

Black98T/A

iTrader: (5)

Ok I think I'm getting somewhere..my speedometer is not correct even with this stock pcm...now could this be from a bad vss sensor?

mrvedit

Quick answer: YES!
I (and perhaps others) mentioned several times in this thread that it could be the VSS sensor. I don't know how the VSS sensor can partially-fail, but I have read other posts here about people solving their no-WOT-upshift problem with a new VSS.

When the PCM detects WOT operation, it uses a different algorithm to determine when to upshift. In particular BOTH the tuned (programmed) speed and RPM must be reached before the upshift occurs. If the speed is too low for any reason (slipping torque converter, defective VSS), then the upshift never occurs. That is why we kept telling you to tune for a lower upshift speed.

A new VSS is only $20 from your local parts store. Give it a try and let us know. Easy to put in too from underneath on the passenger side. Unsnap the connector, one bolt (10mm?) holds the sensor, lube the new one's o-ring with a little trans fluid and install it.

Black98T/A

iTrader: (5)

I tried a new VSS and even though my trans builder roriginally told me that sensor works or it doesn't I bought one anyway...no luck speedo is still 10-15 off and still no wot shift.

My speedometer is off with both a tuned and stock pcm..with a correct speedometer I will probably get the shift at wot but how can I fix it??

Black98T/A

iTrader: (5)

Well I'm taking the car to another shop tomorrow that does speedometer repair I don't know what else to do at this point I've tried 3 different tunes, 2 pcm's 2 different sets of tires, a vehicle speed sensor and the speedo is still off and the trans is not shifting at WOT

mrvedit

The gear ratio is one of the numbers in the tune, but if you have a stock rear end ratio, close to stock sized tires, then a stock PCM should be very close. Well, get the obvious problems fixed first and hopefully that will cure all. Good luck.

Black98T/A

iTrader: (5)

This is what I don't get

Oct 08-I bought car basically stock all it had done to it was a lid and Flowmaster. 3.23 gears and 315/17 tires. Speedo was correct and car shifted at WOT.

Jan 10-I have PCM tuned for ls6 crate. I list car has 3.23 gears on order sheet. Speedo and WOT upshifts are correct.

Nov 10-295/18 go on in rear I notice no difference in speedo wot shift occurs

May 11-I notice trans is not shifting at WOT I don't notice speedo being off also. Transmission starts to slip and car is parked until rebuilt trans feb 12

So something caused the speedo to be off right around may of last year which caused my no upshift at wot which possibly caused my trans to go. I just remember being on the highway and passing someone and the trans not shifting and smelling something burnt and feeling the trans slip right after.

Black98T/A

iTrader: (5)

Ok just an update...I took the car to a tuner today he hooked his laptop up and we went for a ride, I also had my iphone speedo app on. The first thing I noticed about the car being off last month was the tach, I remember being on the highway cruising and seeing almost 3k rpm and feeling that can't be right, I later noticed my speedo was off when cars started passing me, my iphone app confirmed speedo was off and any wot shifting I've been doing I've been letting off as to not blow the motor right before 7k rpm except 7k rpm isn't 7k rpm it's about 6k rpm! The tuner adjusted the tables to correct the speedo like he gave it a higher gear which corrected the speedo but not the tach and lowered the shift points a little, We did a couple of wot shifts from a dig and a roll, I let the tach go to 7k rpm and yes the wot shifts occur so basically spedo is correct now, the tach is still off and shift points are a little lower then optimal for performance but it shifts. I'm going to try a used cluster and if that corrects the tach, tune the shift points back up and adjust the speedo for the correct gears...if the cluster doesn't fix the tach then I don't know in the wiring somewhere??