Blue/green wire ID

[monkguru]

I'm trying to ID a wire I thought was black, but it appears to be a light blue with a green stripe on it, it has a rubber cylinder in it. The other half is missing and since Im having starting issues again, I noticed this wire and want to find out where it goes. Its rather long and was draped hanging around under the area of the coil. Any ideas?

 

[RonD]

You can check thru these diagrams: http://www.therangerstation.com/tech_library/EDiagrams/index.htm

I looked briefly and nothing jump out at me.

I assume the cylinder on the end is 1/2 of something??
So you are missing the other 1./2 and the rest of the wire??

Light Blue would be LB
Green is G

So light blue with green stripe wire would be LB/G

 

[Earl43P]

http://www.therangerstation.com/tech_library/WiringByColor.shtml

Seems to be missing from this list, Hmph.

Are you sure its a WIRE, not a vacuum hose/tube?

 

[monkguru]

Yes Im missing the other half. There is a big grey colored cylinder shape connector. On this are blk/w , yel/red , and either grey/lt green or blk/lt green. I thought it was blue/black, but after some cleaning it sort of looks grey.

 

[monkguru]

 

[RonD]

So there are 3 wires on the one connector?????

It is probably for an option your truck doesn't have.

 

[monkguru]

It appears to go to a sensor above the starter, Im assuming an oil or knock sensor? I dunno.

 

[RonD]

From another thread:
"'86-87(2.9l) had a knock sensor. It was a 2 wire connector and located just above the oil pan(starter motor side). There was also a low oil indicator switch located in the oil pan on some models on the same side. It is only a single wire."

 

[monkguru]

86 2.9 ranger not starting

Going down the highway it made a few popping exaust type noises stalled and that was that.
This is what I know so far. I had issues before not starting in the rain so all elec. connectors were cleaned and that solved the problem for over a year.

Now. I seem to have spark at the plugs. I have pressure at the fuel rail, but I do not have a tester. I tried starting fluid in the brake booster hose to the intake and nothing. I have almost 13 volts to the battery, but only about 8 when cranking. I have tried a booster as well. It cranks somewhat slow. I have 135 pressure accross all cylinders except 1(105) 4(110) I wish I had my previous readings, but I cant find them. Distributer spins and seems clean. Any ideas would be appreciated.

 

[RonD]

Slow cranking would account for low compression numbers, 2.9l has 9.0:1 compression ratio so should be coming in at 160psi at sea level with all spark plugs removed and throttle propped open, to get crank spinning as fast as possible.

Starting fluid is ether so will ignite much easier than gasoline, even with lower compression.
The fact it didn't fire at all or even backfire(spark at the wrong time) would mean to me that you don't have spark at the plugs.

Battery with 12.6v or higher is a fairly new battery, dropping down to 8v when cranking means starter motor or cables are drawing too many amps, expected drop when cranking is 3volts, getting below 9.0volts means there is a problem with battery, starter relay, cables or starter motor.
But that shouldn't cause a no start, just a heads up for future issue.

TFI ignition systems are 25+ years old now and will have failing parts.
You can try putting a jumper wire from Battery + to Coil + this will make sure coil is getting power for cranking.
Good read here on TFI testing: http://www.therangerstation.com/tech_library/TFI_Diagnostic.shtml

I would start with ignition system, get engine to fire using starting fluid, if it does fire up and then stall you can start looking at fuel system.

If you have or can get a timing light I would disconnect SPOUT and crank engine to see if spark for #1 is happening close to TDC mark on crank pulley.

 

[monkguru]

battery to coil or starter? I have only checked one plug for fire, I think Im going to have to check the rest. I dont have a timing light and thats about above my pay grade. heh

 

[RonD]

Battery positive to Coil positive(it is marked with "+"), this makes sure coil has power when cranking starter motor.

The distributor/TFI module Grounds and unGrounds the coil("-") to get it to spark, that's what Points did in old distributors.
That spark travels to the distributor cap's center post, then the rotor under the cap gets the spark, the spark travels to the tip of the rotor and arcs to the closest post(spark plug wire), spark plug is grounded to head so spark travels down the spark plug wire and jumps the spark plug gap to get to a ground, hopefully this ignites a mix of 14.5 parts air and 1 part gasoline.

Barbaric way run a spark system, lol, but as bad as it is it will work if EVERYTHING is working and setup correctly.


You will need to get a raise
And a Volt/OHM meter($25) or you will waste your time guessing at what may be the problem.