My '99 STS has recently developed a problem of being quite difficult to start after use/when hot. Car turns over fine but coughs and splutters when it eventually tries to start. I have found that you have to depress the gas pedal hard but doing this seems to also cause the car to almost back fire and blow smoke out the exhaust when it does fire up.

I had the spark plugs replaced at 70,000 mile service (now has 82,000), just put a whole new set of ignition leads on, replacement coil pack but none of these has made any difference.

I am wondering if it is a fuel problem because when the car does eventually start there is a strong smell of fuel. I have not removed the MAF and checked the air intake assembly to see if there is a build up of carbon yet, that's on the 'to-do' list.

Last Sunday I got the emissions warning light appear on the dash which has stayed on all week but I have not noticed any difference in power/performance when using the car.

Tomorrow morning I have the car booked in at my specialist garage so they will do a code check and we will see what's stored.

Will report back

 

Just used car (Thursday evening) and emissions warning light on dash went out lol!

 

Code diagnostics showed an error code for anti-theft system, fuel. All codes reset so not sure what that was all about, will run it around and see if all is well. Seems to be running great now.