[warorl]

After searching hours on old forums i thought it was about time to write my own.

A couple weeks ago while driving home from work my engine sputtered and died, and when starting, would die again pretty quickly. However I figured out that if you held down the accelerator, it wouldn't die. This is when the issues started, the car doesn't stall anymore while idling. But after driving for about ~5 minutes normally, you can feel a very noticeable change in its performance, and it is instant, there is a bog and it just loses heaps of power and I think it begins to run rich, and I believe it is only when it is hot cause as I said it runs perfectly fine for a bit. When this happens, it is extremely slow to accelerate, and when I hit around 3500 rpm it almost sounds like it just hits a limiter. This is in a st162, with a 3rd gen 3sge. Any help would be greatly appreciated

Edit: just to mention I am by no means an expert on cars so if I sound like an idiot, it's cause I am.

 

[93celicaconv]

Is your check engine light on?

 

[warorl]

Is your check engine light on?

No it isn't. Done some looking and thinking since then. I checked the ecu and alas the diagnostic box has been completely removed from the car, wires cut right off the ecu, and assuming I read the diagram right, that was the diag box. Not sure if that missing will prevent a cel??
Something I failed to mention in the original post is that, of all things that could go wrong, the infamous throttle stop screw managed to loosen itself, assuming vibrations from my dirt road and a previous owner already adjusting it might’ve finally knocked it loose. The neighbour who knows more about cars than me, adjusted it to where the car idled on its own and didn't stall. But reading around I have heard these things are pinpoint accurate to get the right readings. Could this screw be the whole cause?

 

[93celicaconv]

If your diagnostic port was cut out completely - I'm hoping all the wires that are still there that were cut are capped (or at least prevented from grounding or contacting each other). If all that was done, the removal of the diagnostic port would not cause your previously stated problem and will not prevent the check engine light from coming on. If this wasn't done right, way too many variables exist that would result in problems. Your biggest problem is that many settings are made went a couple terminals from that diagnostic port are shorted to each other (such as proper idle settings, etc.). With the wires cut, you can still identify what color wires to short together to act the same as shorting terminals together, but it makes it a whole lot harder. You should try to understand from the previous owner why in the world he/she would cut out that diagnostic port in the first place.

 

[warorl]

If your diagnostic port was cut out completely - I'm hoping all the wires that are still there that were cut are capped (or at least prevented from grounding or contacting each other). If all that was done, the removal of the diagnostic port would not cause your previously stated problem and will not prevent the check engine light from coming on. If this wasn't done right, way too many variables exist that would result in problems. Your biggest problem is that many settings are made went a couple terminals from that diagnostic port are shorted to each other (such as proper idle settings, etc.). With the wires cut, you can still identify what color wires to short together to act the same as shorting terminals together, but it makes it a whole lot harder. You should try to understand from the previous owner why in the world he/she would cut out that diagnostic port in the first place.

It was a few owners ago that did the swap, the guy I bought it off probably would be just as confused as I was.
I adjusted the throttle stop, and let her sit for about 10-15 minutes and it never dropped in power, praying that when I take it for a drive later it's fine.

 

[warorl]

needed a whole new ECU btw.