I have a 2000 S2000 and have been having this problem for the past 2 months. Every morning when I first start the car, it either runs really rough (starts idling at about 400rpm) and then it will either correct itself (the idle) or just die. From then on its ok. Runs fine. It's just the problem with starting in the morning. I have had it at the dealership off and on for the past few months, and they basically say they don't know. They have replaced the fuel regulator and some other fuel backflow valve thing, but admit the still don't know and are just waiting for what Honda tells them to do next. I'm going to take the car up to Denver and try a different dealership, but was wondering if anyone else out there (especially those with an S) have had a similar problem and how they were able to fix it. TIA , everyone.

 

I don't have an s2000, but on my wife's Integra did the same thing so I did a leakdown test and found out it's something with my head: gasket? warped head? cracked? =haven't pulled it apart yet, but my coolant was leaking slightly into the combustion chamber when I shut the car off everytime so every time I start it up cold, it would idle rough due to the pistons trying to compress the liquid in there. No oil in my coolant however. My suggestion is try a leakdown test.

 

You should let the fuel pump get up to pressure by turning the key to the "on/acc" setting (i.e. dash lights turn on but not cranked all the way to start) and let it sit a few seconds before cranking it. On my car (Type R) you can actually hear the fuel pump spool up.

Most people just jump in their car and crank away - but if you take it a bit slower - the car will start better.

 

But our integra never did that until there was a problem. I always cranked it as usually.

 

Big Phat R:

It has already been suggested to me that I try priming the fuel pump a few times. I tried this many times one morning (like 5) and no change.

 

did they check the fuel pump?

 

Supposedly they have checked the pressure in the line and they said it was ok. They have replaced the fuel regulator and some other backflow valve thing.

 

It might be "vapor lock".

Try checking that the gas cap is functioning properly.

 

check iac and egr

 

Is the cold start phenomenon associated with a low thumping sound when you crank the engine? Does it only occur after a long period of cooling (eg overnight)? If so it is a recall that is being addressed as I write. There are occurences of this in both Civic and Odyssey's this is the first I have seen in the S2000 but, not uncommon. Its due to added pressure on the mobile valve and will be available for repair under warranty soon.