Hard Starting

[Mitchs07explorer]

Car has has been running great for a while now until just recently it’s been taking a bit longer to start. It’s an 07 4.0 advance trac with 140k on her now. What happens is I turn the key and it seems to take 3-5 seconds of turning over to start where in the past is take like a 1/2 second to 1 second to turn over. It started doing this after I took it on a 200 mile drive with no prior indication of any starting problems. It also idles slightly rough when the engine is still cold. I have no loss of power or hesitation when I’m going. Oddly a few times it has fired up just like it always used to. It’s possible the gas is poor quality, we have Maverick gas stations here in Idaho and for years people have been claiming they use poor quality gasoline. It was my only option so I went for it. I had about a 1/2 tank left when I noticed this problem and since I assumed it could be the gas I filled it up with 87 octane non ethanol from chevron plus threw a bottle of Lucas injector cleaner in it. That kind of seemed to help it start just a tiny bit faster but maybe that’s my imagination. Last winter I had to have a fuel pump installed as the original went bad, couldn’t do it myself do to lack of time. In the last 2 months I’ve replaced my vent valve solenoid and gas cap to take care of codes p0442 and p1450. My battery shows 12.7 volts when the vehicle is off so that looks good, the terminals are tight. I’ve tried Turing my key on and letting the fuel pump prime the system and let any air in the fuel line out, I had read that sometimes after a fuel pump has been installed there is a check valve issue that can cause a hesitated start but it seems to still hesitate to start even after letting the key sit in the on position for a few seconds before trying to start. I’m about 10,000 miles shy of my next tune up and can’t imagine it would be the plugs or wires yet. Any suggestions on what I should look for? I’m hoping the next time I fill up with better quality gas I’m hoping the problem will go away but I’m starting to have doubts about that.

 

[D Hook]

I would definetly try new gas first. Be careful not to overfill the tank though. When the pump shuts off, that's full enough. Otherwise the excess raw fuel contaminates the evap canister and leads to more problems.

I would run a couple tanks of better quality gas through before moving on to replacing parts.

 

[Mitchs07explorer]

it was the gas, I got through another half tank and I put some 91 octane in plus octane booster. It starts like a champ again. I might just start using 89 or 91 octane from now on, definitely never get gas from Maverick again.