Hello,

I have a situation I need help with. The truck is a 94 Ranger 4x4 with 4.0 V6 and manual trans. 90K original miles. Just a field truck. It has been sitting for 10+ years. Never failed to start until now. The last time the truck started was about 2 years ago.

Recently I went to start it and it cranks but won't start.

Checked plug #1 for spark, it's good.
Checked fuel at the rail, I don't have a gauge it but it squirted out when I depressed the schrader valve.
The gas was old and rank smelling so I siphoned it all out of the tank and put in new fuel. I pulled the stem out of the schrader valve and let it crank over till I saw new fuel coming out of the hose. Didn't make any difference.

I pulled the bed and fuel pump. I checked the hose from the pump up and it's fine. No cracks and it's still looks brand new and is still flexible. No leaks that I could see.
I tested the fuel pressure directly at the pump, 55psi going thru the key on start.
I tried starter fluid (ether). Makes no difference. It sounds exactly the same as trying to start it on gas.
I have no CEL, except when I turn the key to start and then it goes out when the engine tries to start.
The engine tries to start, runs for 1/4 to 1/2 second then dies.
The tach shows 400-700rpm during this 1/4 to 1/2 second.

I checked both relays in the fuse box under the hood, fuel and ecu. Both click when 12 v applied.
I checked all fuses, all tested good. (test light on both sides). Checked all under the hood and under the dash.
I pulled the connection off the TPS, makes no difference. (some have said a bad TPS will cause it not to start.)

I pulled the connection off the coil pack. You can hear a distinct difference. The engine just spins, never tries to start. Plugging it back in you can hear it go for just a fraction of a second and then die. So it appears the coil pack is working. When I checked the spark on #1, it was at good 1/2" long spark.

I checked the inertia switch. It's not tripped. I did not test the connection since I had 55psi at the fuel pump using the original wiring thru the key so it's working.

The ONLY other clue I have is the radio is dead. Factory AM/FM stereo always worked before but now it's dead. I will double check the fuse on that, but it's just weird. I don't know of a single thing that has a common circuit between the radio and the starting/running circuits.

There was some work done by a local shadetree mechanic a few months before I parked it last time. He replaced the master cylinder and the fuel filler hose.

I replaced the plugs, wires and coil pack at that time. After all of these things were done the truck started and ran fine for a few months. Then I parked it. That was about 2 years go.

I'm told this engine has no cam sensor and I'm told if the tach is showing RPM while cranking the crank sensor is working so I've ruled both them out.

Tomorrow I will check spark on all 5 remaining cylinders.
I will also buy a adapter so I can check fuel pressure at the rail.

At this point my only thought a is fried ECU. The reason I say that is that the radio is dead. I'm thinking maybe the truck got hit by lightening sometime in the last 2 years and fried the ECU. I know that's a long, long, long shot, but it's all I've got at this point. The other option is a really clogged inline factor fuel filter. However the filter sock on the fuel pump looked brand new with no foreign matter on it, sO I really doubt the filter could be that clogged. But once I check the pressure at the rail I'll know that for sure. Could all the injectors be stuck closed? I find that hard to believe.

If anyone has anything else I should check, please LMK.


Thanks for reading this!

 

3 years later and no reply... well I fixed it myself (as usual) Turned out to be the ignition switch. Not where the key goes in but down on the steering column. One of the tabs broke and only half of the wires were making connection. Seems to be a common issue with Fords of the 1990's. I made a vid and put it on YT in case anyone else has this problem.