Any CS owners with rough idle problem?

I haven't noticed any idling problems with mine.

 

A common thing with 360 motors- it seems like the car is running on 4 cylinders for about 5-10 seconds running around 500 rpm, then seems like all 8 are firing and 1,100 rpm when starting the car for the first time in the morning, especially when the car has been sitting for at least several days.

My mechanic said it is common and recommended just letting it do it- don't touch the gas pedal or anything.

I have been using my 360 every weekend for the past several months, and it doesn't do this anymore. I had a mass airflow sensor replaced earlier this summer, but the car still did it for a couple of times after that so I don't think that is what causes it. As I said, my car doesn't do it anymore so could be just the fact that it has been driven without sitting more than 6-7 days due to the nice weather and time on the weekend morning to take her for exercise Maybe something with fuel pressure? If my car starts doing it again say in the spring, it doesn't bother me as it seems to be a normal quirk of the 360.

 

This is probably completely unrelated to your query, but since we have a new generation of CS owners on FChat, maybe worth mentioning. The original CS engine control firmware had a bug which occasionally would result in the two engine ECUs (left and right) not synchronizing on start-up. When owners complained, the dealers would pull the ECUs, send them to FNA (assuming you were in North America) to have them re-flashed with updated firmware. I've always wondered if they fixed them all as there never seemed to be a recall or effort to hunt down the cars needing the new code.

 

on my CS... on cold start the first 3-5 seconds are rough... kind of a gurgling sound. Then after that all smooths out too normal. Only on first start up of the day.

 

Very occasionally, and it didn't matter if ambient temperature was low or high, my car would stumble after a cold start, idle rough and throw a flashing CEL.

Usually, I turn the engine off, count slowly to three, then crank it over again. So far, it's always come back smooth with no more CEL. I'd love to get to the bottom of that but it happens so rarely that it's hard to diagnose.

 

That is exactly the symptoms of the original engine ECU synchronization bug.

 

What else does the updated firmware include, besides having a synchronization algorithm?

(maybe I'm being too presumptuous, it's probably just a timer, like "sleep 10" or something )

 

It fixed the ECU synchronization issue and doubled my MPG. There was also conjecture that if you always waited for the OK light to appear prior to starting the engine, you would never suffer from the bug. Never proven......

 

Then reason for the rough idle is valve adjustment and it is in a limp mode if you will temporarily until it adjusts then back to all firing. Have a Friend with a CS and does it regularly. I have had two 360(s) and both have done this if not driven regularly.

Cheers,
David

 

Humm, I'm beginning to think if a 360 DOESN'T do this once in a while during an initial start after sitting for several days, something is wrong with the car

 

My 2000 does this as well first thing in the morning for about 1-2 seconds. I figure it is clearing is throat AND bugging my annoying neighbors.

 

We have put together some performance software for my CS to match my intake and exhaust... and it 'explodes' when it comes to life!

 

This is what I've heard as well. What's the tab on reflashing ECU?

 

Samething happened to me, when I went to china and had to put in some cheap gas. But when I replace with full tank of quality Caltex gas back home Hong Kong problem solved.

I was told by my dealer, that you turn the key for 3 seconds then hit the start button, let the ECU and all sensors warm up first, that should solve the problem.