1994 Ranger 4.0 V6 cranks but won't start. Tried all the normal things. Grasping for straws here. One weird clue.

[BrightCalypsoGreen]

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 WEIRD clue 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.

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


Thanks for reading this!

 

[Josh B]

Hello BCG, welcome to TRS

You'll need much better advice than I can offer, and that will likely be overnight.

I can offer this, when you let off the key after it fires up, it switches from the "start" wire, to the "run" wire, AsFarAsIKnow,(AFAIK )

Maybe it's an ignition switch issue

 

[Dirtman]

Have you checked for spark on the other 5 cylinders? You obviously have fuel so it's a spark issue. You could have a bad coil pack (it's one peice but divided into 3 parts) a faulty ignition control module, or since it's been sitting for so long just regular ole worn out plugs/wires...

But first need to confirm spark or not on ALL cylinders.

 

[Uncle Gump]

KInda sounds to me like it is flooded...

 

[rusty ol ranger]

Maybe im missing something here but....

Try holding your foot on the throttle about 1/4 way and see if it runs. It could be the IAC (idle air control) is gummed up from sitting and not opening to allow it to run.

Might not hurt to pull the air cleaner and tube and make sure rodents didnt turn it into a huge blockage.

Sounds like you got fuel and spark...so all thats left is air/compression.

 

[alwaysFlOoReD]

Some collapsed lifters?

 

[black_demon69]

burnt valves?

 

[Dirtman]

42

 

[BrightCalypsoGreen]

Thank you to all who have replied.

To address the issue of flooding, that's not it because I've let it sit for days and and still will not start.

The ignition switch feels fine, but the fact that I have no radio and the power windows will only operate when the key is in the start position seems to indicate it could be there.

I also checked the fuel pressure at the rail. It's only 20psi. The fuel pressure at the tank was 55psi. So someplace I'm losing 35psi. Also the fuel pressure drops after I stop trying to start it to zero w/in about a minute. Not sure if that is normal or not. There is NO smell of gas anywhere. I know the pump runs for 2 seconds and then turns off till the RPM comes up to 500 and then turns back on. But I am surprise it drops that fast that much. Anyone know what the pressure should be? I'll try a fuel filter swap, as it's never been done, so can't hurt anything.

As for the spark testing the other cylinders, I need a helper to do that and so far I have not found someone. I will try again tomorrow.

It's not burn valves, as the truck ran very well last time (And everytime) I drove it.

As for collapsed lifters, I can see one or two, but not all 16. I did check the oil and it's full. Old, but full. Once I get it started I will change it of course.

It's really acting like there is a kill switch on the car. But that I can recall I never put one on it. I have been known to do such things.... but I have looked at all the obvious places that I would put one and so far I can't find it. In fact when I parked it two years ago I thought I had pulled the fuses for the fuel pump. So that was my first thing to look at. But the fuse is there and good. Where I parked it, there was an issue of possible theft so doing something like a kill switch and pulling a fuse would be likely. Problem is, I can't remember putting a kill switch on it and I have checked all the fuses. The clutch switch it working. Ie no clutch pushed in, nothing. But pushing the clutch down it at least turns over. (that's a quick trick I used to use back in the old days.) But it's hooked up, so that's not it.

And why no radio....

 

[BrightCalypsoGreen]

Maybe im missing something here but....

Try holding your foot on the throttle about 1/4 way and see if it runs. It could be the IAC (idle air control) is gummed up from sitting and not opening to allow it to run.

Might not hurt to pull the air cleaner and tube and make sure rodents didnt turn it into a huge blockage.

Sounds like you got fuel and spark...so all thats left is air/compression.

I'll pull that open the filter box tomorrow and check. There are some ground squirrels around here and rabbits. I will also check the IAC, I recall having trouble with that in the past. I did replace it with a ford part but that was 5-6 years ago.

 

[alwaysFlOoReD]

Fuel pressure should be at least 30 psi and around 40 is normal when running. The pressure should stay for months without leaking down. You have an internal leak somewhere. Pull the vacuum line off the FPR ( Fuel Pressure Regulator), smell and look, there should be no signs of fuel. Clamping the vacuum line shut should make the pressure rise to whatever the pump puts out.

Also try turning the key on 4 or 5 times in a row without starting it. Each time the fuel pump is turned on the pressure goes up about 10psi. Then try starting...

Clear flooded engine; hold accelerator pedal to floor and crank engine. There should be no signs of the engine trying to start. The computer stops sending signals to the injectors when this is done. If the engine tries to start its probably leaking injectors or FPR.

 

[Uncle Gump]

I'm still not convinced after all the cranking you've done that it isn't flooded.

Pull a couple easy to get to plugs and have a look.

 

[91stranger]

Have you tried pressing the reset button on the radio. Sometimes when the battery dies the radio will not turn on by itself when a good battery is installed or you get a jump. Not sure what kind of radio you have. I would definitely check a spark plug or two, It takes 2 minutes and it will tell you quite a bit about the engine. You are definitely losing gas somewhere though.

 

[Josh B]

Change the air in your tires! hahaha
By now hopefully you're figured out what's going on.
If you still think it might be a well hidden kill point, try running a completely separate "run" wire

 

[91stranger]

I doubt you hid a kill switch that you can't find.... You can only kill so many things on a ranger so if the fuel pump, ignition or whatever else you can wire a switch to would be obvious at the source, meaning you would see wires coming from something if there was a kill switch.