Engine noise during warm up, PLEASE HELP!
 

Every time when I started the cold engine in the morning I heard some rare noise came from the engine. Like all the FD's the rpm will first go up to about 3k for warming up purpose then slowly fall down to normal rpm range, but between this warming up process the Engine will become "shaky" along with some "da..da..da" noise (the rpm needle also became a little shaky) for about 1 min, after that everything will back to normal, the problem only occur during warm up. This problem already happen when my FD was stock so it don't have anything to do with my mods.........could it be spark plugs???

Any professional advise will be highly appreciated! :icon_tup:

Thanks in advance,
Johnny

Well, a listing of your mods would help a bit...

Also, you shouldn't let your engine go through the warm-up rpm hold. Letting a cold engine suddenly run up to 3000 rpm for several minutes isn't the healthiest thing for its longevity. When you start the engine, stab the throttle quickly to get the rpms to drop; the rpm hold is only to light off the pre-cat quicker.

its all the damn vacuum lines and little solenoids kicking off the AWS its during this time when its switching from warm up mode to nomal idle. my FD did it as well and most of them i have seen ( we are talking a little bit of shaking and irratic idle northing crazy )

I believe you can start the car with the clutch in, in first gear. This will disable the warm-up cycle. You could always try to remove the warm-up system. Take a look at the sticky sections in the forum. Other than that, when was the last time you did your plugs? With everything I usually start with the simplest things like plugs. Good luck sorting it out.

One of the first mods back over 10 years ago, was to disable the 3k cold start.
This let's it run off the normal 1.5k cold start.
Why hasn't this been done?

3k warmup has been provem somewhat harmful to the motor. i would disable it.

can you tell me more about the warm up,how do u disable it and why?alsoI believe you can start the car with the clutch in, in first gear. This will disable the warm-up cycle.ive never heard this but have only owned an fd for 9mths but ive notised mine starts better with out opp the clutch..odd or not...thought it might be something being an fd...and help much app..

Revving at cold start is bad for any engine. Go to the FAQ thread's reliability mods to learn how to disable the FD's AWS among other things. (The Accelerated Warmup System causes the ECU to rev a cold engine at 3000 RPM. )
Until you disable your AWS, you can "bypass" it on startup by temporarily putting it into 1st or by blipping the gas pedal

yea i never udnerstood what the coldstart 3k crap was for..it sort of went again " don't rev the motor while cold" thing...pretty easy to eliminate though...

The 3000-rpm hold on cold start is for a portion of the EPA emissions test of all vehicles that measures emissions soon after startup. The catalyzer needs to be a certain temperature to be "lit off" and function properly, and with the rotary's poor combustion efficiency, it needed all the emissions help it could get.

will the "Rats nest" solve this problem?

Thanks,
Johnny

i used to have that. i had it tuned out with my aem

so I just need to replace the aem? please advise, thanks!

Even with the AWS disabled the enigne still revs at about 1500 RPM which I believe is due to the wax rod crap(correct me if I'm wrong). I just see that and think how much gas my cars eating. :(
However I believe he means AEM ECU which is a standalone ECU such as the Power FC. I don't recommended disabled the AWS unless you want to have more problems cause if you have the original vac hoses then they will crack on you when you take off the UIM. So don't worry about it unless you want to do a little bit more work.