beerman4679

Sorry to revive an old thread, but just to give closure... it ended up being the fuel pump as many people pointed to. Took it somewhere to get it replaced since it's been pretty cold and snowy in Ohio, but got it done anyways. Car starts easier and doesn't chug/hesitate under heavy throttle so everything appears to be all good. Thanks for the help guys,


Brian

wrihar

I had the same problem on my 2000 mustang 3.8. I did the usual things like change the plugs and fuel filter but that did not help. It always cranked for 5 to 8 seconds before starting after it had been sitting a while.
The problem long cranking or hard starting problem turned out to be a leak in the hose going from the fuel pump to the fuel tank flange (in the tank). This is a special flex hose that had a pin hole in it. It allowed the pressure to bleed down after a few minutes. You need to drop the tank and remove the flange on the top of the tank to get access to it. I simply replaced the hose with a high quality fuel injector rubber hose and 2 worm screw clamps.
To verify this is the problem put a fuel pressure gauge on the Schrader valve (tire valve stem type of valve) on the fuel rail. (front left corner of the engine on a 3.8 Liter engine). The pressure should be about 30 psi and 40 when just turn the key on. Newer engines do not have this Schrader valve and you will need to put an adapter in the line somewhere by opening one of the spring clamp fittings... maybe at the fuel filter or on the engine somewhere so you can measure the pressure. You need a special tool to release the spring clamp fittings available at most auto parts stores for a few bucks. I suggest undoing the output line of the fuel filter and slide your pressure gauge onto the fuel filter outlet and then turn the key on to test the pressure. It should remain at 30 psi after you turn the key off.
If you have a problem you will note the pressure will bleed down after you turn the key off.
If it bleeds down it could only be 3 things. A leaky injector, a bad check valve in the fuel pump or a leak in the hose ... which was my problem. The pressure should be maintained for a long time (in the order of days) after turning the key off.
As a work around to keep from cranking so long and killing your starter and battery you can cycle the key on and off a few times to charge the rail before starting. This will give you time to prepare.... and get the tank empty so you can drop the tank easily.
If you need to replace the fuel pump Napa sells the fuel pump by itself for $152. Most other auto parts do not stock it.
Good Luck.