Hey guys!!! :-) new to the forum and new to the gt4 Celica.

I have a 3SGTE GT4 ST185

My problem is that the car boosts really hard when the car is warming up to temperature but as soon as the car gets warmer the car seems to goto retarded mode and the car pings slightly and only hits 5psi. Then while I'm driving it sometimes boosts hard and then I can feel the car going into retarded mode or limp mode :-(

So cold ish to warming up its ok but then warm for awhile it goes into limp mode


And there is no error codes :-(

Any help would be amazing!

Here are photos of the car too just to get a rough idea

How much boost are you hitting? Is factory fuel cut disabled?

You are either hitting fuel cut, or knock response.

have your checked for error codes?
Sounds like you have a problem with heat soak or one of your sensors?

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The car is factory, has no mods so i'm not sure if it will hit fuel cut, YES I know there might be knock response but why should it knock?

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No error codes, I just checked this morning :-( What is heat soak? I was thinking about tricking my ECU to think the air temp is 20* by bridging the air temp wiring with a 3k resistor.

This is what I have done so far.

Full Engine Service. (Engine Oil, Filter, Fuel Filter, Fuel Line, Gearbox oil, diff oil, Spark Plugs, Leads, Radiator Flush)
Pulled the 15A EFI Fuse to rest ECU
Eliminated the fuel pump relay
Put an HKS Intake after photos
Changed the MAF (checked resistance and checked OK)
FUEL: 98ron

On the way: Full Vacuum Line Kit to replace all lines

I did suspect that the fuel pump is the issue but when the car is warming up its fine and I would assume that it would be richer as colder = richer so there couldnt be any signs of not enough fuel when warm I would assume :-)

Appreciate your input so far guys.

Have you checked your ignition timing ?

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I checked it, it's on a static 8*. I know it should be 10* but I put it to 8* to be safe.

Heat soak usually applies to people with mods like induction kits and removal of heat shields etc... its when heat is given off more from things like aftermarket manifolds and exhausts and the shielded intake is taking I hot air.
However after seeing pics I realised yours is running stock so I doubt it applies to you.

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Yeah :-(, Curious though, when does the radiator fan usually come on?

Try setting the static timing back to 10* and see if it does the same thing.

We have a similar problem with our ST165, but I know that its a knock sensor wiring issue. Plus, it throws a code for knock (That you can only pull when the car does it).

Drive around until the problem occurs and try pulling the code right then.

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Could be a go'r, I will give that a go BUT one feeling I have is that the ECU should store these codes :-P. BUT im willing to give it a go. I do how ever want to check that my water temp sensor in my radiator is working so im going to just buy one and slap it in just in case :-)

No codes

Question, What if I have too much OIL in the car? OVER "F" quite alot....

Hey guys! found the issue, sorry I couldn't say thank you on the video, I DO THANK YOU VERY MUCH FOR HELPING ME OUT

http://www.youtube.com/watch?v=biTZRhwhyq8

Who da hell would had thought that you'd have a wrong ecu plugged in? Did that one come with the car?