This case is from this car https://ls1tech.com/forums/conversio...lle-lq9-5.html

I have two things I would like some input on... No. 1. When you accelerate from 0 and hit the gas, the car jumps like a kangaroo / jerks. This case has nothing to do with the transmission, but I'm mentioning it here anyway, as maybe someone has something smart to tell me...

The most relevant topic is this .... When you are at high speed and are about to shift, the engine revs up, before it downshifts and then revs back up. It feels like the car is in neutral between gear changes and the engine revs up. I don't have any fault codes, but could this be an electronic fault, or is it a fault with the transmission?

 

I'm not sure that I understand the problem, is it happening on the up shift or down shift? Have you check the fluid level?

 

I forgot which but its going to be a valve in the valvebody starting to get stuck, pull out sensors and valves and spray them and orifice clean.

 

up shift...

 

Is it happening on every gear shift or the 2-3 gear shift and by high speed do you mean high RPM? What RPM? Does it only happen at full throttle/part throttle? All of the time, every shift? We are not driving the car, so we rely on the information that you give us, the more the better.

 

Does it happen at every gear shift or 2nd-3rd gear shift, and by high speed do you mean high RPM? What RPM? Does it happen only at full throttle/part throttle? All the time, at every gear shift? We don't drive the car, so we trust the information you give us, the more the better.[/QUOTE]
I'll try to explain as best I can (sorry for the bad language). When I drove the car, there was like a built-in delay for every gear shift. Of course I've checked the fluid level, and the problem is not there. All gear shifts are at too high a speed, giving me the feeling of "waiting for a gear shift". With a light foot on the accelerator, the gear shift from 1st to 2nd goes normally, but hopelessly when you press the gas pedal all the way down.... When I drive the car over 40 mph and press the accelerator..., the transmission goes "bananas"... between gear shifts there is a long pause, and the RPM goes high,/the engine accelerates, before the transmission/transmission is engaged, and the power comes back. My simple question is, is this major fault something with the sensor/control unit, or should I just return it to the company that overhauled the gearbox last year.... I think the gearbox needs to be overhauled again..

 

Is this the 1st transmission that you put in the car since the engine and trans swap. I'm thinking that the tune is not right but if there was another transmission in the car before this one and it didn't act like this, then most likely it's not in the tune.

I have not taken the time to read your build thread.