1998 Ford Ranger...Help will not start!

[NJ Esperantist]

It did it again to my wife last night and to me twice today.

With my wife the truck had sat for at least an hour and a half. After it did not start, she called me as she was only about 5 minutes away. When I got there, she had successfully started it.

Tonight, I pulled the truck out of the driveway and parked it on the street for about 10-15 minutes. When I went out to leave, it did not start. I twiddled with the ignition key for a minute and then it started.

As I was taking the truck out to get a fill up, thast's where it happened the second time. I had to wait about 15 minutes till it started this time.

HERE'S WHAT I NOTICED

When it does not start, the Check Engine light does not come on when you turn the key to the 'run' position. When the Check Engine light DOES come on, it starts.

The check engine light does not stay on while the engine is running.

ANY IDEA WHAT IS CAUSING THIS?

Originally Posted by NJ Esperantist

No, I have not solved the problem, but I'm working on a theory. What if it's a sensor connected with the ignition somehow? So far (the past 2 weeks) I've allowed the engine to idle for about 15 seconds when I'm about to shut it off. So far I have had no problems. If it does happen to me again, I'm going to try opening the gas cap for a moment to see it that does the trick.

Either that or I'm wondering if it couldn't be one of those computer things.

Dave Rutan

[rburrhead]

This is the first time I have had this trouble. I am going to have it towed in for repair.
It acts just like I pressed the gas peddle before starting,wich I have not done,I learned about that the hard way. I am going to try the gas cap, and the air filter trick first. Is ther a way you can tell me (non-mechanic) which relays you are talking about.
Thanks

[Mike J.]

NOTE: If you live in a HOT CLIMATE (anything above 85-90 degrees), it's posible the fuel pump is VAPOR LOCKING. This was a common problem with fuel pumps in some FORD Taurus' and Sables. DO NOT replace your fuel pump with a third market pump, you must get the NEW pump from FORD to get the new design. I learned this the HARD way with my '93 Taurus. It took me MONTHS to figure out the problem because I used a non-Ford replacement pump. Don't get a used or rebuilt pump either, it must be NEW. I live on the coast in Los Angeles and mine would only fail if I travelled inland into hotter temps (no problem during the winter, of course). At times it acted a lot like your troubles, drive fine, turn it off, go to start it a few minutes later and no start. Other times it would quit running while driving. Let it set for a while or wait for the temp to cool, and it would start and run fine. I had my car towed in from the desert (returning from Vegas), by the time it got to the shop, evening was upon us as well as cooler temps. F**King car started immediately off the tow truck and ran ran fine all the way home!

However, I haven't had this problem (yet) with my 2001 Ranger, but barring the above note and looking through my Haynes wiring diagrams there are 3 circuits and 2 relays that can cause this trouble.

As NJ pointed out, his CHECK ENGINE light is a good indicator that the PCM circuit could be bad.

For those that get a proper check engine light with the ignition on, but no fuel pump noise, then the FUEL PUMP circuit could be the problem.

The following 3 circuits that MUST work right for the truck to start. Here's the power paths:

CIRCUIT 1: Power to PCM RELAY coil.
From HOT with Ignition in RUN/START Position to>
:
:->FUSE 19, 25 AMP to>
. :
. :->NOISE CAPACITOR
. :
. :->POWER DIODE to>
. . :
. . :->PCM RELAY COIL (activates the relay, see circuit 2 below)

CIRCUIT 2: PCM CIRCUIT POWER
From PCM POWER MAXI FUSE, HOT at all times, 30 AMP, to>
:
:->PCM RELAY SWITCH (activated by CIRCUIT 1 above) to>
. :
(RED WIRE to the below locations)
. :
. :->FUEL PUMP RELAY COIL (activates the switch, see circtuit 3 below)
. :
. :->PCM (this is where the Check Engine light circuit starts)
. :
. :->CRANKSHAFT POSITION SENSOR
. :
. :-> FUEL INJECTORS
. :
. :->IAC VALVE RELAY COIL
. :
. :->EVAP CAN PURGE VALVE RELAY COIL
. :
. :->EGR VACUUM REGULATOR RELAY COIL
. :
. :->MAF SENSOR

CIRCUIT 3: FUEL SYSTEM CIRCUIT POWER
From FUEL SYSTEM/ANTI-THEFT MAXI FUSE, HOT at all times, 20 AMP, to>
:
:->FUEL RELAY SWITCH (activated by CIRCUIT 2 above) to>
. :
. :->PCM (Tells PCM Fuel Pump Power is ON)
. :
. :->INERTIA FUEL CUT OFF SWITCH to>
. . :
. . :->FUEL PUMP

So, if no CHECK ENGINE light, make the following tests:

1) Test CIRCUIT 1. With IGNITION in RUN position, test the RED/LT GREEN wire at the ignition coil for +12 Volts. If Okay, proceed to 2) below. If no +12 Volts, turn ignition to OFF and check fuse. If fuse is bad, test the NOISE CAPACITOR for a short. If noise capicitor is shorted, replace it and replace the fuse. If there is less than +12 Volts, then test the NOISE CAPACITOR for resistance. Capacitor is bad if anything other than INFINITY resistance is measured. You would think some voltage would be ok, but it's not. In this case, the capacitor is reducing the power to the relay below it's operational point. It can be intermittant because the capacitor could be heating up and cooling off, changing it's point of failure. If still no +12 Volts, suspect a bad ignition switch/circuit.

2) Test CIRCUIT 2. With IGNITION in RUN position, test the RED wire at either an INJECTOR or the MAF SENSOR for +12 Volts. I suggest these as they're the easiest to get to. If Okay, proceed to test 3). If no +12 Volts, turn IGNITION to OFF position. Suspect a bad PCM Relay or blown PCM FUSE. A blown fuse could indicate a shorted part in CIRCUIT 2 above.

If CHECK ENGINE light is on make the following test:

3) Test CIRCUIT 3. With IGNITION in RUN position, test the two wires into/out of the inertia cut off switch. BOTH should have +12 Volts, which will indicate good power from FUEL RELAY (Dark Green/Yellow wire) and out of the INERTIA switch (Pink/Black wire). If OK, then suspect back fuel pump or loose wire in fuel pump circtuit. If no +12 Volts, then suspect blown fuse or bad fuel pump relay.

Keep in mind, ANY failure in any of the three circuits can cause the no start condition. ie: bad relay, loose ground, carboned connector, bad ignition switch, etc.

PLEASE, PLEASE, PLEASE BE CAREFUL WHILE DOING THESE TESTS. ALL ARE FUSED AT OR ABOVE 20 AMPS, WHICH CAN KILL YOU!!!

mj

[jabernathy2]

Try resetting the inertia switch located in the panel box on the passerger side. Push the red button in to reset. The inertia switch usually activates after a

My son had this same situation where the switch was activated. This was after we had already replaced the fuel pump, fuel lines, and the relay switch.

[wow]

You should first check and see if it is firing by removing a spark plug and cranking it while watching the plug (plug must be grounded to metal on vehicle). If the plug fires, you probably have a fuel problem. The fuel filter or the fuel pump could be the culpret. If it does not fire, you may need a new coil.

[horseweed]

Originally Posted by ikescull

Here's my problem, for over two years my 1998 Ford Ranger 4X4 4.0 6 cylinder has intermittently not started after it sets for a while.

Last August 2005, I took it to Autowerks in Valdese, NC and they gave it a major tune-up. The "failure to start" problem went away for about a month and then started again.

When it happened the next time, I found that if I took the cover off the air cleaner it would start. I called the repair shop and of course they would have to see the vehicle again. I opted to use the "cover off the air cleaner" solution, until last week.

When I tried to start my truck in my driveway, it wouldn't start even when I used the "cover off the air cleaner" solution. I did notice that when I turned on the ignition I didn't hear the usual electric fuel pump "pump up" that I was used too.

It's dead in my driveway, couldn't drive it to the repair shop, and didn't want to pay for a tow...

So, using my trusty Haynes Repair Manual as guidance, I decided to go the least costly way and replace the fuel pump relay. Naturally, it was not the problem. I then checked all easily accessable fuses and relays, under the hood and inside the cab, all to no avail.

I then removed and replaced the old fuel pump with a new one, and a new in-tank filter. I also replaced the "on frame" fuel filter.

After reconnecting, the fuel pump wiring harness, the inertia switch and then the battery, I was all excited and ready to hear the pump "prime up" after I turned on the ignition switch.

You guessed it, not a sound, except the engine trying to crank, but no fuel...

I know this is a long email, but hopefully in your busy schedule you might help shed some light on this problem.

Did you ever find out the problem

[BroncoJoe19]

Horseweed,
Other than Mike J's post, this is a real junk thread.
IF you are having starting issues, start a new thread, with specifics about what it is and is not doing, year model and size engine, and what you have tried so far.
joe