I have a 2000 EX and I live in the SF bay area in NorCal and I just recently did a tune up to try to fix a low RPM stuttering issue that seemed to have been a little bit of a common thing around here and I was somewhat satisfied with the results. The stuttering has stopped but the good ol' butt dyno still felt as if there was still something lacking in the power department... Now that summer has come around I really am noticing the difference between the way it was during the colder months and the warmer days we've been having more recently. The car feels a lot spunkier during the hot parts of the day and then when night rolls around and the air cools down it starts to feel like it is being held back. I'm a little confused as to why this would be so because the cold air into the engine would seem to be a better thing than the warm air but it seems to be the exact opposite.

If anyone happens to have any insight as to why this would be so, all suggestions and ideas are greatly appreciated.

Mitch

 

Bump for any ideas at all.....???

 

What did you do for the tune-up? What parts were replaced, checked, etc.? Any difference in performance between when the motor is cold and after it has fully warmed up?

 

The cold air is most deffinetly better for the engine itself, but some sensor may not like the less dense or colder air, somthing like the MAF or IAT sensor could be at fault

 

During the tune-up I replaced the plugs, wires, cap, rotor and the fuel filter. And yes and no to the difference in performance between the engine being cold or being warmed up... The performance feels good all the time during warm/hot weather (~80F+) but during weather less than that it can feel a tiny bit better up until the car is warmed up then i just get stuck with the 'MEH' performance:/ I was directed to check the IAT sensor on another forum and I am sure its plugged in but I don't have the tools available to check if it is faulty or not right now...

 

So, it's not going to be an ignition problem. It's something screwing up your A/F ratio. Is this "Meh" performance straight through to redline or does it seem stronger at high RPM WOT? Try going to Autozone and borrow a fuel pressure gauge from their loaner tools. You'll have to put down 80$ or something as a deposit but you'll get it back when you're done. Warm the car up to normal operating temperature and then test the fuel pressure with and without the regulator vacuum hose attached. You can perform the test in the store parking lot and then just return the gauge. Post the results and post when you have a meter to check the sensors with.

 

I actually just went and changed the IAT sensor with a new one from autozone and it actually feels a lot better! I wanna say that that was the problem! Thanks for the advice! Would you still suggest doing what you've just recommended to possibly help figure out if there would is anything else worth figuring out with those results???

 

Is this engine stock?

 

Besides an AEM V2 intake and some suspension work yes...