Sometimes when I try to start my S2000 (happens only during first start in the morning) the car will vibrate quite a bit and sound as if it's choking (like as if the pistons are stuck to the cylinder wall) for about 2 seconds before it starts up. Could it be my spark plugs having firing problem? Any clues?

 

wow from ur description, it could be anything... please elaborate...

Its like when you go to the doctors....
u say: doc I have pain
doc: where
u : here
doc: takes out the scary instrument.....does it hurt here, here, how about here......


BEroz

 

i think its the ECU adjusting due to warmer temps in the mornings now.

 

Squeezer may be onto something. In Vancouver, I imagine it's quite humid now and getting warmer. Give it a few more cold starting cycles and see if the ECU has learned. If not, then look towards things like spark plugs, MAP sensor, air filter, bad gas, dirty injectors, etc.
Also, try this: Just before you push the start button, let the the fuel pump pressure up the system first. You'll know it's finished went that initial buzzing stops.

 

It actually happens only when it's cold........the car is still sitting in the garage now and will be till at least till mid - end of April. I haven't driven the car since November. The first time it happened was after the plug recall which is why I'm betting it has something to do with the plug but yeah with cars nowadays you never know....

 

Hmmmm, you didn't mention this part before. It is possible that the tech who installed the plugs did not check and confirm the gap but simply took them out of the box and screwed them in. It might be wise to have the gap checked now as well as confirm the torque.

Also, if you have garaged your car all winter and go out and start it once in a while (first of all, this is NOT is wise thing to do for a stored car), your climatic conditions change so dramatically from one start to another, the ECU must be going nuts. It does not have any hope of learning the parameters for the next time you go out and start it.

 

I thought the buzzing was the ABS accumulator? If your check valves and fuel pump are good, you should have more than enough residual fuel pressure in the fuel lines to start up on the first crank, so you shouldn't need to let pressure build, right? Iunno.


As far as the vibration and choking, your ECU is just letting you know it's not happy. Low rpm = rough idle = engine vibrations. Give it time.

 

I see...........hmmm.....I guess the first thing I should do once I insure the car is to get the plugs checked to see if they are probably gapped. Well that low rpm=rough idle=vibrations equation seems very credible too but I mean the car has 18000 miles already....shouldn't the ecu be learned by now? Well as long as it's not the result of pistons or cylinder wall damage I'm happy.

 

NO, you must understand that the ECU learns ALL THE TIME. Whenever your climatic conditions change (outside temp, humidity, air pressure), the ECU needs to gather information to run the engine. It doesn't just learn once and use only those parameters to run the car. Many people have cold start problems every year just before winter hits because the ECU has trouble coping with the sudden change in temps. You must also understand that this is a very high output, high performance engine (240 HP out of 2.0L). The ECU controls virtually every aspect of what the drivetrain does far more than any other "lower output" engine ECU has to.
The mere fact that you have been driving the car since last year made it very hard to the ECU to keep up with the changes outside. Most stored cars can but yours may have other issues that, when combined, is producing what you see.

 

Well ever since I owned the car back in 2001 I have always driven the car 6 months out of the year. From April to October. So it never sees Winter at all. So are you saying that I should start the car once a week during those 6 months that I don't drive it? I thought I read in this forum somewhere that it was bad to start the car and not drive it..........
Either ways after I get the spark plug checked out what should I do from then on to help assist my ECU through the storage period?