What's up guys,
im new to this forum but my love for the Ford Ranger is old as dirt.

I have an issue, I just bought my 90 4.0 last week and I have been very happy with it until Monday morning.

I've been driving it since last wedWednes with no issues at all, in fact, when I parked it Sunday night it was still fine but on Monday morning at 4 am when I turned the key I got a lot of chugging but it wouldn't start.

I've researched and taken care of all the issues that seem to be common.
- checked the inertia switch, no issues
- cleaned battery posts
- listened out for fuel pump running, it wasn't
- checked the fuel filter, it's clean and free flowing
- checked fuel pump relay, it was bad
- I bypassed the fuel pump relay and fuel pump runs
- getting good solid fuel pressure to the fuel rail now

Truck still won't start.

I know, I know, I know

Fuel, compression, spark is all I need

**While writing this I saw a wire hanging out of the alternator that is very obviously not doing what it's supposed to but could that prevent starting**

The things I know for sure
- plenty of battery power
- fuel pump IS working
- fuel pressure at fuel rail seems strong


I don't have a multimeter so any suggestions for checking for spark are appreciated, I'll try to get a couple good pictures of my alternator situation for reference and post them here.

HELP!!!!

 

Welcome to the forum

If starter motor speed seems OK, not "chugging", then next step for a No Start is the 50/50 test
Spray gasoline or Quick Start(ether) into the intake and try to start engine
If it starts and then dies fuel delivery is the problem
If it doesn't start then Spark is the problem(or compression)

Fuel pump running is good, fuel at the rail is good, but doesn't mean fuel injectors are opening.

So do 50/50 test
If it doesn't start then my guess would be Crank sensor problem.
If is located next to crank pulley about 10-11 o'clock position.
It reads a tone wheel on the back of pulley, looks like a gear with teeth

The Crank position sensor TIMES the spark and fuel injectors, so when it quits nothing works, its the BIG KAHUNA of sensors, it took the place of a Distributor

In 1990 crank sensor is wired to EDIS module, it rarely fails but not never fails, it is usually located on Rad support, engine side OR Grill side
Looks like this: http://www.mkosonen.com/edis6module.jpg

EDIS runs the Coil Pack, check connection on coil pack

EDIS sends crank sensors timing pulse to Computer(PCM) and it uses that pulse to time fuel injectors


If vehicle is a repair from a front end crash then EDIS module would be suspect, it often gets damaged in front end collisions because of its location

 

I replaced crank position sensor, fuel pump relay, eec relay and still the same result.

I realized yesterday that the EEC fuse was burnt so I replaced it and the truck started and ran for about 5 seconds. When I checked the EEC fuse again, it was blown so I'm assuming I have a short or bad ground. I spent all day taking apart wiring harness looking for the short but no luck. I checked the harness that goes from the driver's side down through the frame and to the transmission, the harness running from the fuse panel down into the bottom of the truck and I just can't seem to find it.

Any suggestions on common areas that short or ground issues?

 

EEC Fuse powers the EEC(computer, of course), but also powers the fuel injectors, the IAC Valve, the MAF, the EVAP Valve, the Coil pack and EDIS module.
Also powers Fuel Pump RELAY, not fuel pump, just the relay.

Automotive 12volt relays follow a standard lay out
Look here: http://www.enginebasics.com/Advanced...%20Picture.jpg

Shown is a 5 pin relay but it can be 4 pin as well, 87A would be missing

Why they used this numbering is a mystery lost in time, lol, but they do and thats the standard.

The slots for Pins 30 and 87 are the ones you will be checking

Remove EEC relay, KEY OFF
Put new EEC relay fuse in
Use a volt meter set for DC volts
Slot 30 OR slot 87, in relay's base/socket, will have 12volts, thats from the EEC fuse, test which one is 12volts

Which ever slot, 30 or 87, does NOT have 12volts will be the slot that powers all the above and the wire with the short somewhere.

Switch Volt Meter to OHMS, 200 scale, GROUND one probe on the meter, and hook other probe to SLOT in the relay's base that was NOT 12volts.

Should read LOW Ohms, because there is a Short, since it took 5 seconds for fuse to blow it might not read 0 OHMS which is called a DEAD short, a partial short will still blow the fuse, and you will see Low Ohms from that.

Now with OHM Meter hooked up unplug the MAF sensor, see if OHMs change, plug it back in if it doesn't, unplug IAC Valve, check OHMs, ect.................for the list above.
Also move wiring harness around while watching OHM Meter, if there is a short in the harness OHMs will jump HIGH when you move that section of wire.
High ohms is no short.
So if you unplug IAC Valve, for example, and OHMs jump high then IAC Valve has internal short

The fuel injectors have ONE Red wire, from EEC relay/fuse, it daisy chains from one injector to the next, but I doubt these wires would be shorted, but give the Red wire a close look, unplugging the injector wire won't tell you much because shorted injector wouldn't blow a fuse, just Flood the engine.