Hard starting when hot and code P0405?

RUNOXX

MEMBER
2004 FORD EXPLORER
4.0L
V6
4WD
AUTOMATIC
215,000 MILES

So, my vehicle starts perfectly fine in the morning, or after it’s been saying 7-8 hours, it’ll start perfectly, but if I take a drive and get the engine warmed up and shut it off for anything more than 5 minutes it’ll have trouble starting. Usually crank it for 4 seconds, stop and it’ll fire up within another 2 seconds of cranking. I’ve tried clear flood mode, which doesn’t help at all. I’ve changed spark plugs, air filter is still good, I’ve run injector cleaner in the tank. Nothing changed. It also will usually start easier on E85 as well. I’m assuming maybe a leaky injector. But I’m not too sure as I don’t smell gas, no gas in oil or anything, and no hydro lock or anything. Truck only has P0405 EGR Sensor A Circuit Low code. I just ask for an extra opinion on this to see what else it could be before I spend the time to strip the injectors.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,420 POSTS

If it was a leaky injector one of the spark plugs would be darker than the others and this will be the cylinder that has the problem. Also, when it won't start hot try to unplug the coolant temperature sensor to see if that fixes it telling us the sensor is bad, also I would cap off the EVAP purge line temporarily because if it sticks open the engine will suck in raw fuel causing the problem. Here is the location of the coolant sensor. Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.

Images (Click to make bigger)