I was on the freeway (jammed), everything was fine until when I got near my house the engine started vibrating like it was going to stall when i let the engine idle - but it remained near 8-900 RPM during the idle. i got REALLY nervous thinking that maybe all the cylinders weren't firing correctly? or maybe the infamous #4 cylinder failure was going to hit me, but the vibration went away after about 30 seconds, and didn't come back. i nursed the car back home - maybe i should change my plugs? any suggestions? what's the early warning sign for the #4 cylinder failure?

 

Did the revs drop all the way down in idle then the car started shaking? Or did it just start shaking around 800-900RPMs idle?

 

[QUOTE]Originally posted by Shamu
[B]Did the revs drop all the way down in idle then the car started shaking?

 

Richard,

That sounds like something I've encountered numerous times during stop-n-go traffic. Most people seem to think that it's MAP sensor related, but others have mentioned the IAT sensor too.

My scenario goes like this.

I'm stuck in traffic doing the stop and go thing when the car seems to bog when traffic starts to move. It is also sometimes accompanied with a lurching action that makes it look like I can't drive my car. I'll have to put the clutch in and rev the engine to get over the bog zone and then it's okay for a while. It's like the engine is not being supplied enough gas. Sometimes it just doesn't go away and I have to limp home.

I've talked to my mechanic at and he is going to try to duplicate the problem(hopefully with an OBDC laptop) when I bring it in for my 60k service. I'm just curious what the problem is since it doesn't seem to be serious enough to cause a CHECK ENGINE light to come up.

If he turns anything up, I'll let you know.

Joe

 

Now that its gotten warmer here, I notice that my S2K stumbles after filling the tank. embarrasing when it stalls.

 

Mine ALWAYS does the stumble and lurch thing when I'm in traffic with the A/C on. It's kinda embarrassing.

 

I've had the same symptoms in stop-n-go traffic on warm days.

 

I'm going to have to get inline with everyone else, heat and stop and go traffic is a problem. I've wondered if maybe the gas line is to close to the engine and becomes hot. Hot gas leads to poor combustion.

When setting at a light, I gently rev the engine and this seems to help a lot.

 

Any chance the car is suffering from Vapor lock? I had an old shelby charger many years back that did the same thing. On hot days in heavy traffic, the fuel lines would heat up, boiling the gas. The car would start bucking until I got it back up to speed and air cooled the engine compartment.

 

well, the weather really wasn't that hot yesterday...and if this type of temperature in stop-and-go traffic would cause fuel boiling...