Have a 95 Ranger with 3.0 v6 with only 52k miles. It runs very well but over the past month it's gotten real hard to start. Have to turn the key over a couple times (3-4 seconds on each try) before it will rumble to life. The starter turns the engine over just fine. Before this started it would bump to life by just looking at the ignition switch. I should add that this really only happens when the truck is cold or has been sitting for a few hours or more.

Earlier this summer I replaced the spark plugs (Motorcraft) and air filter. The problem above didn't begin till many months of driving after the new plugs & filter were installed.

Last night I installed a new Motorcraft fuel filter. It seemed to start good right after, but went inside a couple hours, came out and it's now right back to the old problem of having to turn the key a couple times.

What else might be causing this to happen?

 

Weak initial fuel pump prime? If turning the key on and off a few times before cranking it does the trick, then you might be looking at a dying pump.

 

Good idea to have replaced the fuel filter imo. Maybe perform a fuel pressure check at the under hood fuel rail Schrader valve test port. Pressure at idle, with the under hood fuel pressure regulator vacuum hose Connected, should be 25-35 psi. At idle with the FPR vacuum line Disconnected & plugged, 35-45 psi. So with the vacuum line Disconnected, psi should rise.

Also, check the FPR vacuum line to make sure it isn't wet inside with fuel. If it is, the FPR diaphragm is leaking fuel into the intake manifold, so replace the FPR.

Upon engine shut down, fuel pressure should hold for a while, like half to one hour & not Rapidly drain off.
If psi is low, or quickly draining off & you have rich fuel trim codes, or found carbon fouled spark plug/s, again put a leaking FPR diaphragm, or dirty/runny nose/leaking fuel injectors on the suspect list.

A rich fuel trim computer trouble code for a cylinder bank can narrow down which injectors to begin to suspect & a spark plug read of the old plugs, for black sooty deposits, can narrow down which cyl injector to move high up on the suspect list, IF you noted which cylinder the plugs were removed from when they were replaced.

If no rich fuel trim codes, or sooty plugs were noticed but the fuel psi drains off, then put the fuel pump anti-drain back valve on the suspect list. If it's acting out, it can cause a pressure drop.

Some more trouble shooting thoughts for consideration, let us know how it goes.

 

Can I use a standard vacuum/pressure hose set like is used with the A/C?

I just replaced plug wires with new Motorcraft wires (same as what was on it before), no change.

No codes are showing on the ODBII reader.

 

Found this how to, will have a go at it now.

 

Struck out finding the correct adapter to use with my compression testing kit.

Looks like I need to head up to HF and get one of these.

https://www.harborfreight.com/fuel-i...ter-62623.html

 

Sounds like a candidate for a failing check valve in the fuel pump. Simple diagnostics on this one, just do the cycle-the-key test.

 

On my earlier model HF fp tester, I had to wrap 3 turns of plumbers ptfe ribbon dope to seal the threads so they wouldn't weep fuel, as other users have said they also did, but other wise it worked ok to check fuel pressure. Mine didn't have the dump valve, to bleed off fuel pressure, or to use in performing a Volume over Time flow rate test, so that was a thumbs down.
To get the dump valve model I was gonna have to pony up about 3x my gold!!!! With a little fore thought, we can rig a dump valve with some brass plumbing parts!!!!

 

Just to clarify, should I expect actual fuel to go through the shrader fitting and into the compression tester I bought yesterday?

came down with a bad cold so I haven't fooled with it yet.

 

When I read your post, I thought maybe a stuck idle air control valve. Have you checked it? This would cause hard starting and very rough idle until engine warms up.

 

Truck runs smooth as silk when it starts up (cold) and continues running smoothly when warm.

 

If the fittings will leak liquid/fuel, they'll leak air, so it's possible I suppose, that fuel could get into the compression gauge.

 

Truck is running like a top again. Replaced fuel pump assembly with a $42 unit from Rock Auto. Starts by bumping the ignition just like it used to.

I didn't have a helper for the bed so I used my tractor loader to lift it sideways off the rail about 2'. Put a block between the bed & frame just in case. Didn't take long to swap out at all.

Next is to replace the headliner but thats another thread.

 

Ok, way to hang in there & persevere on your trouble shoot to see it through to a successful ending & good feedback on replacing the fuel pump assy fixing the worsening start problem.