Why DO turbo's do this???? (cutting out above a certain rpm)

[Guest bastaad525]

Okay, it's already pretty much been established that the ZXT ECCS system doesn't have any 'memory' or learning ability to speak of... that technically it cannot be 'reset', after powering it down and turning it back on it will still do exactly the same thing that it always does (in theory at least!).

 

So... why is it, that so many times, if the car starts running badly... like today, I was fiddling with the timing, and went for a 'test drive' afterwards, and suddenly the car just did not want to pull... if I got on the throttle the car would pretty much just cut out... it would run fine at just normal cruising but anything more than like 1/3 throttle the car would sputter and hesitate and just didn't want to go. I pulled over, turned it off, disconnected the three plugs from the ECU, left it unplugged for like a minute, hooked everything back up, and suddenly the car runs fine! This has happened quite a few times... the very common problem that many turbo conversions have is suddenly and inexplicably not wanting to rev past say 4000 or 5000 rpm... and like 9 out of 10 times unplugging and replugging in the ECU will solve the problem. Why is that?

[Guest Nic-Rebel450CA]

In a way, it has no learning ability, but technically anything that has sensors that it uses to change something that it controls can "learn" and be "reset". While it does not have a learning mode or ability, it can still get a bad variable in it that gets stuck that can be dumped when the memory is dumped.

[SleeperZ]

If it's very consistent like that, always coming back OK after being unpowered, it could be a code problem.

 

As far as another possible cause, my car ran like crap when I had some plug wires die on me. It happened suddenly, one minute fine, then the next, awful. But it never recovered, even after unplugging. I ended up switching to a Z31 ECU, only to have the same problem still!