Car redlines at 4500 RPM

[Cervantes]

I've been having issues boosting too high since my boost controller crapped out on me. I have already bought a new one, but I just need to wait until a shop has time to install it. Now the issue is that no matter what gear I'm in, my car redlines at 4500 RPMs. As in once I get to 4500 RPMs it acts like I've relined and it won't rev up any further. It does this while it's parked or if it's on the road. The check engine light is also on. I disconnected the battery to see what it would do, and the check engine light went away and the car drove normal for a few days. Now, it's doing the same thing again. Is this something the car does on it's own to protect itself from blowing up since I'm boosting so high? Could it be something else? Any help is greatly appreciated.

[02_Legacy]

always start by getting the check engine code read. We can help you alot more if we know why the light is on. It only takes a miniute or so and I'm sure you can find a place that will do it for free even in Japan, then again I don't live there. lol

[jey]

Yes, it's in limp mode.

[Cervantes]

i'm thinking its due to my car over boosting....hopefully i'll have this fixed by thursday or friday. thanks.

[2000gtb]

will it pass the 4500 mark when you are easy on the gas (not boosting as much)???? if so you are in limp mode... when you overboost, the ecu will put your car in fail safe mode to "protect" your engine from grenading

[Cervantes]

it wouldnt go past 4500 at all. i reseted the ECU and have been taken it easy. its running really good right now. i'm just going to take it easy until i get the boost issue resolved in the next couple of days.

[2000gtb]

if the CEL is on and with out boosting you CANT pass 4500 then its the ecu... if overboosting was the problem, it will let you pass 4500 without boosting... but start with fixing the boost controller and eliminate that culprit... and if it still doing the same with a good boost controller then start looking at the crank sensor etc..

the question is what is making the ECU put itself in fail safe mode???...

[02_Legacy]

the question is what is making the ECU put itself in fail safe mode???...
that is why you need to get the CEL code read, it will most likely answer this question.

[Cervantes]

it was allowing me to boost, i just couldnt go past 4500 rpms.

[2000gtb]

but once it hit certain boost.. it cuts it...

so lets go back to reading that CEL before this goes further... best place to start without confusing anyone

[rougeben83]

Is this on the new tuned ECU or still on the old one?

[Cervantes]

it happened on both, but once i actually gave the new one time to completely reset itself, it hasnt done it. i also havent been riding it as hard, im waiting to put the boost controller in so i can lower the boost.

[lord flashheart]

ive herd of a lot of people who do trans swaps run into this problem. essentially the sensor that tells the car what gear its in is not working. so the car thinks its in neutral and cuts the fuel. but i have no clue if this is what you are experiencing. just food for thought..