1990 Ford Ranger 2.3 Crankshaft Sensor

[basaraski]

So I bought this truck over a year ago. Wiring was a mess when I got it. Looks like a rats nest. The truck started stuttering a couple months ago, and completely died the other day.

Signs point to the Crank sensor. It'll start, run like crap, and then stumble and stall.

I have a question about the wiring coming out of the sensor. There are four wires (red/black/grey/blue) and then one more wire coming out of the sensor.

What is that singled out wire go to? Mine is clearly snipped, or broken because it goes to nothing. I dont know if it wore away, and that's what killed the truck, and had it stumbling for months. I just want to learn more on what that single plug does. Can anyone help me?

I circled it in the picture below

 

[RonD]

Welcome to TRS

Crank sensor uses 4 wires
Can't see connector, so if it has 4 wires then that 5th wire is a shield wire, and can be left unhooked or hooked up, wouldn't matter

The 2.3l Lima used a timing belt and it can slip or break when it gets over 80k miles, doesn't hurt engine if it breaks, just doesn't run

The more common issue with spark system is the ICM, ignition control module, bolted to the front of the intake, they run hot and do fail, causing what you described, rough running and then no running
ICM wires get brittle and frayed as well, and ICM need a good case ground, and its bolts/screws get rusted out

Crank sensor is connected to the ICM
Crank sensors rarely fail, its possible just way way down on the list of rough running or no start symptoms

 

[basaraski]

Thanks for the help! The 4 wires on the CSS were already cut and re attached to the plug, and we're loose. So re connected them nicely, and re did the shield wire, because why not. Let me ask you more about the ICM.

Before this happened, on the road, usually around 3/4 grand rpm in 3rd, 4th or 5th sometimes it would hiccup very bad. Like one big jolt then recover. Also at idle, say at a red light. Sometimes it would randomly drop to 400/500rpm and stutter while ididling. On occasion it would stall, but not too much. It would also smell very rich when rough idling. Could this have to do with a failing ICM... And then it finally failed and now I'm at where I'm at?

 

[basaraski]

Thanks for the help! The 4 wires on the CSS were already cut and re attached to the plug, and we're loose. So re connected them nicely, and re did the shield wire, because why not. Let me ask you more about the ICM.

Before this happened, on the road, usually around 3/4 grand rpm in 3rd, 4th or 5th sometimes it would hiccup very bad. Like one big jolt then recover. Also at idle, say at a red light. Sometimes it would randomly drop to 400/500rpm and stutter while idling. On occasion it would stall, but not too much. It would also smell very rich when rough idling. Could this have to do with a failing ICM... And then it finally failed and now I'm at where I'm at?

UPDATE: Rewired. Still nothing. Saw driver side coil pack wasn't even bolted down. Spark tested all on driver side. 3 was practically never firing. When manually grounding loose coil pack, the idle returned to almost normal, but under load it would still stutter. Need to replace the pack, and go from there I think.

 

[RonD]

Coil packs don't need to be grounded externally, but do need to be bolted down

The ICM needs to be grounded

After engine is running/idling you should unplug the 3 wire connector on one coil pack, to disable that coil pack
This engine ran fine from 1974 to 1988 on 4 spark plugs, so should still run fine
If you get a steady misfire then at least 1 spark plug on the working coil pack, is not working

Test both coil packs this way

1989-1994 2.3l disables Intake side coil pack/spark plugs when cranking engine over to start, 1995-2001 doesn't
Intake spark plugs will start working when engine is above 400RPMs, started
You should be able to start the engine with just the Exhaust side coil pack plugged in, if that's easier than unplugging it while running

Dual spark plugs were added for more power, there is no alternating, both spark plugs in one cylinder fire at the same time, or there would be no point in dual spark plugs, no extra power

So test if engine can run OK on each coil pack, as said it will have slightly less power but should run smoothly, all cylinders firing

What spark plug gap did you use?
Should be 0.042-0.044


On the engine is the fuel pressure regulator(FPR)
It will have a Fuel Line(return) attached and a Vacuum hose, remove vacuum hose and check it for gasoline, shouldn't be any of course, if there is then thats causing alot of the problem, and Rich smell

 

[basaraski]

After correcting the wiring the truck seems to idle more normally at 1k. But trying to give it any gas, it's drops to 400/500 rpm, and then stutters and stall, leaving a very rich gas smell from exhaust. Tested all exhaust coils and they spark correctly.

All the plugs om exhaust side were very gapped at about .060 and worn. For the meantime I gapped them down to .044, but am picking up 8 new ones tomorrow. Haven't looked at intake side plugs yet. Should I fix all plus first, before buying a new ICM/Coil Pack?

 

[basaraski]

UPDATE:

removed intake side coil pack completely (one that was loose) and ran the truck. Runs fine now. Doesn't read RPM but I assume that's because coil pack is missing. Like you said, runs normal, just not a much power. So either shot coil pack, or ICM is sending weird signals to that side causing irregular running. Going to get coil pack and plugs and try it. If issue remains will buy a new ICM.