Hey guys its a 93 3.0 liter 2 wheel drive. I've been fixing all sorts of stuff and it runs and drives great but I've noticed lately it's been taking quite a bit longer to fire, like several seconds. I've replaced the PCV valve, flushed cooling system and replaced the coolant temp sensors and thermostat/rad cap, brake booster check valve, idle air control valve, cleaned MAF with MAF cleaner, cleaned throttle body and all fittings and reset idle per factory spec, changed plugs/wires/dizzy cap. Basically the air and the spark are good. I'm not sure why the longer cranks, I have no check engine light and i can hear the quiet whirring of the fuel pump when i turn the key to ON. Also if it means anything to you the engine has a slightly rough idle, its not unbearable but there's an occasional vibration you can feel in the seat when idling almost like a misfire. Not sure what to do next, maybe someone can point me in the right direction.

 

Cycle key on and off 3 times then try to start, this Primes the fuel pressure 3 times, to see if pressure is the issue

Do 50/50 test when engine is cold
Spray Ether(quick start) into the engine then try to start
If it fires up quickly then spark is OK
If not then spark is the issue, might be weak or TFI module on distributor is starting to fail

You don't mention setting base spark timing?
When was that done last?

Also test battery voltage after it sits overnight
New battery will be 12.8volts
3 year old = 12.5v
5/6 years old = 12.3v, and time to shop for battery sales

12.2v and lower means battery has failed, and voltage will drop very low when cranking engine, under 9.5volts, so spark gets very weak

 

I can test the battery tonight but I can assure you it's probably fuel related. I found the trick in another thread where you cycle the key 2 or 3 times to prime up the pump more and if I do that it fires much faster. The only PM I didn't do yet on this truck was a new fuel filter, and it's a rust belt truck so I can only imagine it being a bitch to get off. I did the fuel filter on my grand marquis so since it's another ford I'm sure it will be a similar job, but I haven't done it yet.

As for base spark timing, I have no clue how to do this to be completely honest with you. Ignition and cam timing is something I've never done and I'm always hesitant because I don't want to destroy my engines (either creating a knock or a piston slap, yikes)

 

Its not very hard to check or to change if its off

You need to ask around to see if someone you know has a Timing light, these are not used much any more but don't go bad, lol
Its a strobe light that connects to the battery and #1 spark plug wire
It pulses the light each time #1 spark plug fires

On the crank shaft pulley are timing marks
And on the front cover of the engine is a timing needle/line
When strobe light flashes you can see the timing for #1
Recommended setting is 10deg BTDC(before top dead center) for #1

But to test this you must disconnect the computer timing advance wire to the TFI Spark module, this wire is called the SPOUT(SPark OUT)
On a 1993 3.0l engine Ford installed a SPOUT Connector(well on all engines with SPOUT, lol)

On yours it will be below battery near Rad support, its just 2 wires that run into a grey or black connector with a removable tab, to disconnect the 2 wires
You can then view timing with timing light
It is best to have engine fully warmed up to check timing, as it will struggle to run cold with SPOUT disconnected

Video here of where SPOUT connector is on 3.0l Rangers:

 

Not trying to argue with you but i wanna ask, why are you steering me towards timing? Is that responsible for that idle issue as well?

 

Yes, spark timing is the starting point for gasoline engine operation
Next is compression, without compression a gasoline engine can not be started, liquid gasoline can't be ignited with a spark, only gasoline vapor can be ignited with a spark
Compression = HEAT, this heats up the cold gasoline so it vaporizes, you need 30% vapor in a cylinder for a GOOD spark to work
This is why gasoline engines need to be Choked, even fuel injected engines
Computer Chokes the engine by adding extra fuel, this is to try and get that 30% vapor point while cranking over the engine
This extra fuel can drown a weak, or mistimed spark
The cranking builds up heat, so the longer crank time may be needed because spark timing is off so spark plugs are firing too soon or too late until the temp gets high enough to dry out wet cylinders and spark plugs


General speaking low fuel pressure is noticed first at highway speeds, lack of power because you are literally "running out of gas" at higher demand
It could be your fuel pressure is 0psi for start up, but longer cranking time wouldn't change that, pump does not come on again until engine starts or you cycle the key off and on again.

Low fuel pressure doesn't effect idle, just higher demand, if low pressure was effecting 1,000RPM think of what you would get at 2,500RPM a stalling engine

Spark and spark timing effects it all

 

I tested the battery voltage after the truck sat for a long time, just to be sure. Got like 12.45 or so. I went ahead and pulled the ground straps at the driver headlight off and sanded down everything, and even ran an additional ground from there directly to the intake manifold. This didn't seem to change anything.

The question I have is if the timing was off then why is this issue only recently surfacing? For the first few weeks I owned the truck it seemed to fire pretty fast, this has only been going on for the last week and a half or so.

 

Have no idea why it might be spark timing

Suggestion is to take it off the table by checking the spark timing then move on or fix it
You did work on the distributor, i.e. changed cap, maybe it moved a bit or is now loose

Diagnostics basically comes down to finding out what ISN'T causing the problem, which gets you closer to what IS causing the problem
Point of doing the 50/50 test is because its a quick way to find what isn't the problem

If you go directly to what you "think" is the problem you will usually waste more time
In my younger days I spent an hour on a friends car trying to diagnose a crank but No Start, he was out of gas, diagnoses bad fuel gauge, but I "thought" it was the fuel pump, lol, I should have checked for fuel first after 50/50 test got a startup, basic no brainer, but I missed it and wasted an hour, but still remember it, so learned something

It could be the fuel filter, since it starts faster with 50/50 test than without adding fuel directly, but once running it should stumble at higher RPMs/demand if fuel flow is the issue

 

It sounds kinda like old muscle when you start it, with almost an idle lope like youd expect on a sleepy carbed v8

 

Put in new fuel filter, new rotor, and new ignition coil tonight. Idles much smoother, no more shaking, although it still doesnt feel silky smooth like my grand marquis v8. I understand a v6 is inherently unbalanced and chalk it up to that. 2 things may have helped: dizzy rotor had corrosion on the contacts, and the fuel filter i could NOT blow through, whereas the new one i could blow through just fine. Still too soon to tell if the long crank issue is fixed yet though

 

still long cranks! My theory is the check valve in the fuel pump that holds the fuel psi up with the engine off is shot. I've come to this conclusion based on 3 things:
1) long crank time after sitting over night but not if I shut it off and then go back to start it again a few minutes later (like getting gas or going into a store)
2) cycling the key a few times BEFORE starting to help bring the pressure up makes it fire almost instantly. If I don't do this it will crank and crank and then sputter alive.
3) when I went to change the fuel filter, I went for the schrader valve on the fuel rail to bleed the pressure off before disconnecting the old filter. When I depressed the schrader nothing came out (so no fuel pressure in line)

I don't know how bad ignition timing would line up with these symptoms. Cycling the key would do nothing to improve the startup if the ignition was off.

 

Well, short crank startup within say 20 min of shut down would mean fuel pressure is not dropping to 0psi quickly, so..........cycling the key should work after overnight shut down to build up pressure

The fuel pump doesn't get 12volts after the initial 2 second "Priming" with key on, no matter how long starter motor is on, so you could crank all night and not get a startup if pressure was 0psi

 

So then what is it that you are implying here?

 

Check fuel pressure