Have a 1993 F150, bought new, 350.000 miles. When turning the key the engine would start in one or two seconds, since Thursday it now takes about 10 seconds. Checked battery, alternator, starter and cables: no issues.
Placed fuel pressure gauge on fuel rail: 50 psi while turning the engine on, idling or engine turned off. Replaced fuel filter Saturday.
The truck runs smooth (can't hear it idling with windows up) and runs great at any speed. Something has changed but haven't found the answer. No check engine coming on either. Used Fluke 75 meter checking for voltage at battery (drops to 11.7 during starting), 12.6 with engine off, alternator is 14.6, no voltage drop from positive or negative battery terminal to starter during starting or across starting relay. Removed starter anyway having it tested on machine at the auto parts store & passed. Both fuel pumps working good finding no dirty fuel when replacing the fuel filter.

 

Hi handyjohn,
A quickie, you did not say anything about spark plugs , wires etc. What is the history on those items?

 

Hello Hank,


I replaced the spark plugs, spark plug cables, distributor cap & rotor a year ago. Replaced battery (maintenance free, 850 CCA) almost two years ago. Placed a Fluke amp-probe (DC) on the cable from the positive battery post to the starter (engine cold) and the meter read 438 amps. Fuel gauge on the fuel rail reads 50 psi even with the engine turned-off and waited 15 minutes before I removed the fuel gauge tester.
The engine will turn healthy until it fires and I release the key. I don't suspect a faulty battery but being sealed cannot test each cell.

 

Once the engine starts do you smell a rich condition?

Your indicated fuel pressure is a tad high and could be the fuel pressure regulator is leaking fuel back into the intake causing a flood condition.. Not a high failure rate, but given the mileage, something to check and prove out..

Spec pressure S/B 30-45 running, 35-45 KOEO..

 

After the engine is running it runs very quiet & smooth and you can't hear or feel it when idling or at 65 mph. No odors but noticed its harder to start as motor cools. Will fire up immediately if I turn it off and back on quickly but starting it in the morning when cold it takes longer. That is why I purchased a fuel pressure gauge Friday thinking the fuel lines were bleeding down but holding at 50 psi either tank (dual fuel tanks).
I used a new pair of jumper cables placing them at the battery straight to the starter (just to see if my battery cables to the starter was the issue) but the result was the same.

 

A leaking fuel pressure regulator won't have as much (if noticed at all) affect when the engine is running and/or has been restarted..

A leaking regulator will allow raw fuel to back out of the regulators vacuum line and on into the intake manifold. After some 'sit time' or overnight the the un metered fuel in the intake makes for a harder start condition..

After some sit time, pull the vacuum hose of the regulator, if any fuel is present, the regulator is leaking..

Does 'cycling the key' ON a few times prior to a morning start help with firing times?

 

Replaced the distributor & ignition module today and starts quick. Not sure how to adjust the timing but will ask. Thank you for your help.