won't rev past 4,000 with new tach

I had the engine running great then I put in the tach, now it will rev past 4,000 but in gear it won't climb past 4,000. I had a problem 2 or 3 year ago when it would'nt rev past 4,000 but I fixed that now I have this new problem. Does anyone have an idea where I might start or maybe know what to reset?

You didn't even say what you are working on and didn't provide a tune or log file.

That was very stupid of me, I have been beating myself up about this and wasn't thinking. When the weather changes here so I might be able to do up a log, my vehicle is an open wheel buggy and it has been raining off and on with a lot of high winds. It's a 1.4 turbo with the 6t40 that is really no help but I will get on it in a day or 2 when I can. I have been looking for a way to log my trans but so far haven't been able to figure out how to get it on the scanner. I haven't been working with my hptuner enough yet.

Under what circumstances won't it rev up. If you don't have a VSS signal it will NOT rev past about 4000 RPM, period.

I really appreciate the comebacks. I forgot that I needed to get my wideband and some other things to really get a good scan. It will take a little while longer. This project of mine because of delays has taken 3 years to get to here, and I got a little anxious. Please bare with me I will get it together very soon so you gentlemen can help me out.
Sprinto7, the vss are there the system I have is a stock 1.4t engine and auto trans from a 2012 cruze that feeds a 2.32 final drive. I used one of the outlets for the front axles to drive the second final drive. I ended up with approximately a 6.14 ratio to the wheels.

Until I get the wideband and others I have a small question. The setup I have doesn't have a brake pedal sensor to be able to do a crank sensor relearn, is there a way to get it done without it? I think this is my problem because the engine acts like it is being starved for fuel after 4000rpm and until I get that wideband I will have to wait. The widebands are a little pricey for me, is there one that is a good choice but doesn't cost over $300.00 more like $200.00? The dtc's from p0010 to p0017 are all set on second mill and will not clear.

https://www.amazon.com/AEM-30-4110-U...7900589&sr=8-3

$160 bare bones wideband and display

thanks 383-Stroker, but after reading quite a few negative reports on it I think I will keep looking.