1986 ford ranger 2.9 no spark

[Keysd402]

I have a 1986 ford ranger xl 2.9 5 speed 2wd, it has a new distributor, tfi ignition module, coil, plugs wires. there's power to the coil and the ground looks fine, but nothing is sending the signal to switch ground. no spark comes off the coil. there's also 3 connectors on the passenger side that don't seem to have anything to plug into. lastly I saw today that the pcm said in sharpie on the side 1990 ford ranger 2.9 auto, would the pinnouts on this pcm be the same on different years and different transmissions? any feedback will help, thank you in advance.

 

[rusty ol ranger]

Only difference between an 86 and 90 ECM is the 86 ECM will recongize the EGR valve and knock sensor. The 90 ECM will run an 86 engine just fine so thats not the problem...persay.

Try pulling codes....the ECM itself maybe bad.

 

[mnewman]

Check to see if the relays on the passenger fender apron are clicking when you cycle the ignition. They control power to the fuel and ecm. Typically one is Brown and the other is green. They should be right behind the airbox towards the firewall. I can get a picture today if you need it

 

[Keysd402]

Check to see if the relays on the passenger fender apron are clicking when you cycle the ignition. They control power to the fuel and ecm. Typically one is Brown and the other is green. They should be right behind the airbox towards the firewall. I can get a picture today if you need it

Alright I'll check them today, should they be clicking?

 

[mnewman]

Yes, you should be able to feel or here it click. Its energizing the circuit when it does. You could be more scientific and check for voltage but I don't remember the pin out.

 

[Keysd402]

Yes, you should be able to feel or here it click. Its energizing the circuit when it does. You could be more scientific and check for voltage but I don't remember the pin out.

The pinnouts is on the top of the relays, I took them out and tried power probing them on the pin with the coil and in both the green and brown relay there was no click. I also checked voltage and the green relay was only getting about 1.5 v of power to it which I'm pretty sure isn't enough to switch the relay

 

[mnewman]

If I remember correctly there is an inline fuse for the brown relay that supplies the computer but you'd have to cut it out to replace it. Maybe try jumping power to that lead on the relay and see if you get any different results?

 

[RonD]

The PCM is not used for spark when starting, its only used when driving for "load advance" spark timing, like vacuum advance on older systems
PCM wasn't used for spark until newer computers in 1995 Rangers, just FYI

Pins outs on PCM are the same over the years for the 60 pin/wire PCMs

Inside the distributor is a Hall Effect sensor, it sends out a 12v(on/off) pulse to TFI module, this times the spark
TFI module then grounds and ungrounds the Coil in time with pulse, just like points did on older system

So not a complicated system

Have you cranked the engine with distributor cap off, to make sure rotor is turning?

Have you tested for 12volt at coil or TFI when cranking?
In 1986 there was separate 12volt wires for START and RUN ignition key positions
So you could have 12v key on(RUN) but no 12v with key in START(cranking)

 

[Keysd402]

The PCM is not used for spark when starting, its only used when driving for "load advance" spark timing, like vacuum advance on older systems
PCM wasn't used for spark until newer computers in 1995 Rangers, just FYI

Pins outs on PCM are the same over the years for the 60 pin/wire PCMs

Inside the distributor is a Hall Effect sensor, it sends out a 12v(on/off) pulse to TFI module, this times the spark
TFI module then grounds and ungrounds the Coil in time with pulse, just like points did on older system

So not a complicated system

Have you cranked the engine with distributor cap off, to make sure rotor is turning?

Have you tested for 12volt at coil or TFI when cranking?
In 1986 there was separate 12volt wires for START and RUN ignition key positions
So you could have 12v key on(RUN) but no 12v with key in START(cranking)

Yes I have done both, the rotor spins and I get 12v at the coil while cranking, it's also a new tfi module and distributor