Wont start- any ideas

[jrdoubleh]

My son's 98 ranger wont start. It turns over and even when we spray brake fluid directly into it it won't start. Turns over fine. I was assuming that if it was the fuel pump, spraying the fluid directly in would at least start it and then it would die. Changed the spark plugs and wires, no change. Would a clogged fuel filter cause this? I would think it would still start up with the fluid then die. Any ideas? Thanks in advance. And if I didn't use any of the correct technology excuse me but engine mechanics and I don't get along. This is guy stuff as far as I am concerned but can't afford my guy mechanic right now!

 

[RonD]

I assume you mean Brake Cleaner not brake fluid, but some Brake Cleaner is non-flammable so I don't think that is a good test medium, Starting Fluid is what you should have on hand.
And yes, spraying starting fluid into the intake will get engine to start(fire) if it has good spark and compression, and it will die if it doesn't have fuel to continue running.

If you have a timing light you can check for spark.

When you first turn the key on you should hear the fuel pump come on for a second or two, it is priming the system, so turn key on and off a few times and you should hear it, you don't need to crank the engine.
If you do hear it, then pump is probably OK.
If you don't hear it then check the inertia switch in the passenger foot well it has a reset button.
The inertia switch turns off power to the fuel pump if it is tripped(bumped) or fails.

As for no spark the list is long, make sure there are no blown fuses in the Power box in the engine compartment, check for voltage at the coil.
Is there a factory alarm system?
These can disable starting

The crank position sensor(CPS or CKP) on the lower front of the engine tells the engine computer(PCM) that engine is turning over and to start the coil/spark, if this comes unplugged or fails engine will not spark, they are very reliable, so a long shot

 

[jrdoubleh]

Thank you very much for the suggestions. I think I was hearing the pump but will listen again to make sure that is what I was hearing. Will try all the other suggestions as well tomorrow. Changing the plugs wore me out- you would think they would make those things easier to get to, good thing I have little hands! And yes- brake cleaner. lol

 

[RonD]

Were the spark plugs "wet" when you removed them, if so you have fuel getting into the cylinders, or maybe that was brake cleaner

But look at the old plugs, they can tell you the condition inside the cylinders.
Google: spark plug condition
Lots of pictures

 

[jrdoubleh]

The plugs looked good actually, checked all the fuses, all seem to be in working order, one was missing fuse #6 which says Air Bag Electronic Crash Sensor, Blower motor relay, and passive deactivation (PAD) module. Would this fuse be an issue in it not starting? Or the heater not working (another issue). I double checked the fuel pump and I can hear it come on when I turn the key. The brake cleaner says highly flammable on it so I think I can rule out fuel pump, filter. How do you check for voltage at the coil? Is there a tool for that? No alarm system or anything. This may just be above my head and I will have to call a mechanic- or would hooking it up to one of those diagnostic machines work even though I can't get it running?

 

[jrdoubleh]

Another thing, when I was checking the fuses in the engine compartment I saw all the relays- any of those that could be responsible?

 

[RonD]

The coil on the v6 is actually 3 coils, each coil fires two spark plugs at the same time, one is a "waste spark".
I believe they are 1 and 5, 2 and 3, 4 and 6
The coil should have 4 or 5 wires going to it, with key on engine off the red wire should have 12v, the 3 yellow wires are the grounds.
The EDIS module grounds each coil via the yellow wire, to "fire" that coil.
EDIS = electronic distributorless ignition system
EDIT:
Just read that the 1998 4.0l doesn't have a separate EDIS module, the PCM "fires" the coil, so a simpler system.
I would give the wire running down the front of the engine to the CPS a close look, the CPS generates it's own AC power as the crank spins passed it, it is a weak signal to start with so any wiring issues can lower it to the point of the PCM not seeing it, so it thinks the engine doesn't need spark.

The EEC relay powers up the system so yes it could stop the spark if it is bad, and this relay does fail
A bad ground could stop spark as well

 

[jrdoubleh]

Ok so now I am really thinking it is a loose wire or something. Bought a "spark" tester. Hooked it up turned it over and not only did it spark, it started! Shut it off, put stuff back together, started right up again. Next day- started again, drove it ran fine????? Not complaining but I know that SOMETHING is wrong with it, so now I guess we just wait and hope that the next time it decides not to start is when its parked in my driveway.

 

[RonD]

Ok so now I am really thinking it is a loose wire or something. Bought a "spark" tester. Hooked it up turned it over and not only did it spark, it started! Shut it off, put stuff back together, started right up again. Next day- started again, drove it ran fine????? Not complaining but I know that SOMETHING is wrong with it, so now I guess we just wait and hope that the next time it decides not to start is when its parked in my driveway.

What "stuff" did you take apart to hook up the spark tester?

I would start there looking for the loose connections, anything you touched could give you that one clue that solves the puzzle.