Silverstone2K

I'm a new owner of an AP2 for almost 2 months now so I'm new to the S2000 world

I've been noticing random shaking when going to a full stop and shifting to neutral. It has sort of the same feeling like the car is about to stall then it goes away in a couple seconds. It happens randomly so I'm not quite sure how to recreate it or what causes it.

Also, when I start up the car almost every morning now I notice that the rpms are as low as 500rpms for a good 1-4 seconds (depending how cold it is outside) then goes to normal 2000 idle rpms. But, starting it does really go smoothly. Sometimes it takes a couple tries to get it going.

Yesterday morning:
1st attempt: slow cranking. idled at 500rpm for about 3-4 seconds then normal rpm. Then I turned off the car to test it again and it turned on normally


This morning (very cold outside):
1st attempt: took too long to start so I let go of start button. slow cranking
2nd attempt: turned on but died in half a second.
3rd attempt: normal

http://www.youtube.c...d&v=VEezI4XKB5w

I've done a few researching around the forums and see others mentioning IAC cleaning and MAP. Anyone can confirm this?

I live up in the northeast. Hot/humid summers and cold/freezing winters

iamxpl

well from coming to a stop.. a drop in idle could be the map or iac issue. if you havent taken those steps then you should get to it. starting hesitation may be due to a low battery? maybe bad plugs? clog fuel filter? you could try resetting the ECU and doing the re learn procedure.

Silverstone2K

I've tried the ECU reset by removing the backup fuse for a minute then putting it back on and letting the car idle for about 10 minutes with all the electronics off but no luck. I also put new spark plugs last month.

For the battery, I'll stop by autozone to test my battery this weekend.

franky

Clean your battery terminals if there are corrosion. Check your terminals if they are tight and not loose. You should clean the IAC and MAP. If it doesn't help, then i maybe a clog fuel filter or dirty injectors. What fuels are you pumping and if its not chevron, then are you using fuel system cleaner in your tank every month or so?

iamxpl

the re learn process requires you to follow these steps.

1. reset battery

2. turn on ignition and fire her up

3. quickly press the gas pedal and hold at 5k rpm's till fans kick on.

4. once fans kick on let idle for 5 mins?

Also see if you can get your alternator checked. might be dropping voltage.

Silverstone2K

Would it matter if it's a cold start or warm for the relearn process?

iamxpl

shouldnt matter. if its a full cold start give the engine some time to circulate the oil first of course. meaning if your car sat for like a full day. ive never done it full cold and maybe i would advise against that. but maybe billman can chime in later and explain what the proper procedure is. all the times i have done it the engine was warmed up prior.

jl56tc

could be a motor mount issue too!?!

MR.T

This is all correct except for: you hold it to 3k not 5k. And yes it's fine to do on a cold motor.

MR.T

To the OP, there are at least 2 to 3 post a week on this issue and no one has nailed down a definitive cause, mainly because there are a number of things that could cause this. Starting with the iacv cleaning is a good suggestion though. Some folks have had luck with having to replace it.

Look in the "Faq's DIY and maintenance" section of this forum's stickies. There are complete write-ups walking you through all the necessary steps. Be sure to read through all of the comments too, a lot of answers are in people's results.