Please help!!! Need truck for tomorrow!!!

[CableGuyRanger!]

HELP!!!!
I am new to posting however read TRS forums for reference and always gathered my info, I have found similar threads to no avail!

I have a 1996 Ford Ranger XLT 2.3L 5spd 208kmiles

I purchased the truck 2 months ago and do not have a huge knowledge on history of the vehicle.

Truck ran fine Saturday night, made it 50 miles home never shown sign of an issue. went to start her up today (Monday) and truck cranks as normal but will not start.

have already checked-
inertia switch
Fuel pressure (40psi)
Relays, and fuses.

Have just noticed CEL does not turn on at all, however it always has, was on Saturday when I started truck..


I am not getting spark off either coil pack (8 plug 4cyl)

I am at a loss trying to figure out the coil packs now, and just have never heard of a PCM dying quite literally overnight.... any ideas or suggestions?!

 

[Spott]

You imply that you checked the PCM relay, but how did you check it and what did you discover?

 

[CableGuyRanger!]

I am pulling 12.02V out of correct slot for Relay and have swapped Relay for a known working relay, not getting the CEL or any spark which was recommended in other threads to look towards PCM. At first thought it was fuel related.

 

[CableGuyRanger!]

Nothing has changed or anything since truck was parked day before yesterday, she's never given me any starting issues, that's probably what's throwing me off the most.... I have also pulled back timing belt cover, belt is tight and looks to be in decent condition. was thinking this may be a CPS issue however that should not affect my CEL light?

 

[RonD]

If fuel pump comes on the EEC(PCM) relay is passing power to the fuel pump relay.

the CEL/MIL is a ground controlled bulb, so it gets power from a 7.5amp fuse #11 when key is on and then computer Grounds bulb it to turn it on.

Have you pulled out 1 spark plug after cranking engine to see if it has fuel on it, if no spark and no fuel on plug then could be CKP(crank position) sensor is unplugged or bad, CKP sensor sends a pulse to computer that tells it you are trying to start engine, without this pulse computer can't start spark or fuel injectors
And while it is rare CKP sensors just die, no warning just one day they are dead, but a longshot

here is the diagram for 1996 2.3l system:

 

[CableGuyRanger!]

Just checked, pulling 12V also out of harness on both coil packs, I was praying it wasn't a Crank sensor, they are a PITA from what I hear on these 2.3L trucks.... Makes sense as I do have fuel pressure which does not mean injectors are pulsing, plugs are dry.... Bone dry, but there is pressure in the rails. Also explains the lack of spark on intake or exhaust.

To verify the crank sensor is the mean sob down under the timing belt cover right?....

 

[RonD]

On a '96 it should be much easier to get to, it is in a tube on the passenger side of engine on front engine cover, but never remove one myself
Look here, at 2.3l/2.5l diagram: http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f802c54e2

But get the CEL/MIL bulb working first, it will tell you if CKP sensor is not sending a pulse.


One other thing, unplug the TPS(throttle position sensor), then try to start engine.
TPS can send computer 5 volts if wires short or TPS shorts, this will turn off the fuel injectors, it won't effect spark.

Also add some fuel to intake, gas or starting fluid then crank the engine to see if it fires.
You may not know but the 2.3l/2.5l dual spark plug engines only use the Exhaust side spark plugs/coil to start engine, so if you tested intake side spark plug while cranking it would have no spark, that would be normal.

So only exhaust side will have spark when starter motor is turning
Once engine starts intake side plugs/coil starts working

 

[CableGuyRanger!]

Replaced the CKP, looked horrid had massive build up and wiries on connectorr were so corroded they were bare copper.
Cleaned everything up, heashrinked bare copper and put new sensor in (not fun by anymeans) still same issue.

The CEI/MIL Light worked fine Saturday (have a tendency to look being a new truck to me) seems odd it just died out. Could I be dealing with a bad PCM

 

[CableGuyRanger!]

On a '96 it should be much easier to get to, it is in a tube on the passenger side of engine on front engine cover, but never remove one myself
Look here, at 2.3l/2.5l diagram: http://www.autozone.com/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f802c54e2

But get the CEL/MIL bulb working first, it will tell you if CKP sensor is not sending a pulse.


One other thing, unplug the TPS(throttle position sensor), then try to start engine.
TPS can send computer 5 volts if wires short or TPS shorts, this will turn off the fuel injectors, it won't effect spark.

Also add some fuel to intake, gas or starting fluid then crank the engine to see if it fires.
You may not know but the 2.3l/2.5l dual spark plug engines only use the Exhaust side spark plugs/coil to start engine, so if you tested intake side spark plug while cranking it would have no spark, that would be normal.

So only exhaust side will have spark when starter motor is turning
Once engine starts intake side plugs/coil starts working

When I pulled off the exhaust side 2 of the plug wires were broken, conductor still stuck on plug, also plugs exhaust side looked awful, did test spark on both sides using 1 of the good plug wires and a new plug, no spark with that either?

I'm on a tight budget also so throwing parts at it isn't an option, because honestly I'd love to do new plugs/wires, timing belt...

 

[CableGuyRanger!]

Does anyone know exactly how to check and make sure the PCM is receiving power and doing what it should?

Fuse 19 (30amp) is good showing 12v and same with relay (also swapped for known working relay)
Any possible way to check right off the wiring harness?

 

[blueovals]

Just throwing this out there but have you tried to pop start it? I know it doesn't fix the issue but if you have to have it running tomorrow it may just get you by until you have the answer.

 

[RonD]

Here is the power distribution for 1996 2.3l Ranger

 

[CableGuyRanger!]

Just throwing this out there but have you tried to pop start it? I know it doesn't fix the issue but if you have to have it running tomorrow it may just get you by until you have the answer.

As crazy as it sounds I have thought about it, just have no one to help and worse if it won't start then I have to try getting her back up the driveway... But have definitely thought about it and wanted to try it!!

 

[CableGuyRanger!]

OK UPDATE:::

Got up this morning with fresh mind, found my 30amp PCM Maxxi fuse is blown, tried replacing and instantly blows fuse as soon as key hits on... Good news tho the CEL/MIL Light did come on for a second.... So now appears I'm working with a short somewhere in the harness, not sure where to start, anyone have any ideas or common places of failure? I've had 3 Rangers but never any electrical gremlins to chase (thank god)

 

[mkyhmltn]

Check where the harness goes across the firewall behind the engine. Had an old S-10 blazer that the harness had fallen down and was touching the head and melted through the harness, did the same thing.