KA24DE Hesitation after warmed up - please help

[LFOabuse]

Hi All,
Any help on this would be greatly appreciated. I’ve searched and tried a lot of things already, this is driving me crazy.

My engine - 91 KA24DE - loses power after running for over 10 minutes. When I start it up it’s fine and has the normal amount of power, it’s fast. After about 10 minutes of driving it does not accelerate quickly at all. It’s like it lost half of it’s horsepower. I get the same acceleration from ¼ throttle as I do at WOT. There is no CEL. When the car cools down it will run fine again for about 10 minutes, then the problem repeats.

Things I have already done:

Checked TPS –ok
Checked CAS and timing – ok
Cleaned MAF
Properly adjusted idle – it was off, now is perfect.
Replaced questionable vacuum hoses
Replaced fuel filter
Replaced O2 sensor

Thanks in advance for your help.

[NOOB_jdmtizzite]

Id replace your coolant temp sensor, dem bumpin jawns can go bad. And maybe move dat shit to de upper coolent elbow, just tape and dye on da flat part of da elbow before da bleed screw

[s13rookie]

Id replace your coolant temp sensor, dem bumpin jawns can go bad. And maybe move dat shit to de upper coolent elbow, just tape and dye on da flat part of da elbow before da bleed screw

That may have been a good piece of advice, but no one will ever know as its barely readable j/k

You also may want to check your air intake temp sensor. It may be a stretch, but does your timing chain rattle?

[fliprayzin240sx]

Like whats his name said, even tho most educated people couldnt understand it, ECU water temp sensor. Basically the ECU thinks the engines still cold, so its dumping extra fuel into it.

[orion::S14]

...and the knock sensor.

With no timing advance, the car feels __flat__.

So try a known-good knock sensor...there's no way to test the one you have. You could unplug it, just to see...then reset the CEL when it goes off.

- Brian

[LFOabuse]

Thanks for the advice guys.

The coolant temp sensor makes sense, since it's fine once it cools down. I'll try that and check the knock sensor too. I didn't realize there was an air intake temp sensor. I'll have to find out where that is and check it out too.

The timing chain is relatively new and the guides have been removed.