2004 Mercury Sable Starting Issues


#1

HELP!!! I have a 2004 Mercury Sable that has intermitent starting issues. When the vehicle does not want to start if you pump the gas a little eventually it will start. I took it to the dealer who hooked it up to the diagnostic computer. The computer said that is was a Mass Airflow issue and Idle Control Valve. The wanted $600 to fix the problem. Being the non-mechanical type I decided to fix it myself. I saved a lot of money and replaced the parts. But the problem is… It did not fix the original starting issue… plz help.


#2

Geez, I wish you had asked before you replaced the MAFS and IAC. Was the check engine light on? I don’t think that the IAC sets a code so I dunno what they were looking at! At least you have a spare MAFS and IAC and they don’t take too much space. At least not as much as a spare transmission.

Did they check the fuel pressure? Since it is intermittent, it will be hard to diagnose. Low fuel pressure at start-up can often be pinpointed by turning the ignition on for a couple of seconds and then turning it off. Repeat that once or twice and then engage the starter. Cycling the ignition cycles the fuel pump on and off.


#3

Absolutely nothing to do with pumping the accelerator. You replaced the parts - is the check engine warning light on? No? You need a cptr scan. Cheap handheld digital readouts around $30 - $50 more if you want better data. Look for a latent code to determine if there is a sensor problem. If no warning light and no codes, turn the ignition to test position just before crank. Listen for the pump. Wait a second or two and start. No warning codes and no start after hesitation - likely pump but first change out the fuel filter.