Still chasing missfire....UPDATE....SOLVED

[rusty ol ranger]

You will have to trace it out and see where it goes. Lots of green wires under there. You said you had the harness tape off.

I think i answered my own question.

I found a wiring diagram and i *think* its a tachometer wire. It did appear it was never attached to anything...which would make sense cause i dont have a tach

 

[Uncle Gump]

So like... is this issue SOLVED?

 

[Uncle Gump]

I have an 86 EVTM...

You want a diagram from it?

 

[rusty ol ranger]

I have an 86 EVTM...

You want a diagram from it?

if you can post it, the only ones i found were 87\88 but i figured they were the same

I guess whats got me bugged now is the pinging. Obviously the timing is to advanced (havent had a chance to mess with it since thurs).

I can buy whatever was screwed up was preventing full advance with the spout in, but not sure how it affected base timing with it unplugged....i set it at 10 before i found the issue.

Unless its still at 10 and something else is off.

Worse case ill just do it old school and back it off little by little till it dont ping.

Ill know more monday

 

[Uncle Gump]

I'll post what I have a bit later...

Got to finish up my garden chores. Got enough harvest for a batch of pickles... a batch of salsa... and a batch of banana rings.

 

[franklin2]

You mechanically set the timing to 10BTDC with the SPOUT disconnected (no computer control). After that is done, you plug the SPOUT back in, now the computer takes over and sets the timing. The 86 setup did have a knock sensor. I want to say it's on the side of the engine block on the driver's side.

 

[rusty ol ranger]

You mechanically set the timing to 10BTDC with the SPOUT disconnected (no computer control). After that is done, you plug the SPOUT back in, now the computer takes over and sets the timing. The 86 setup did have a knock sensor. I want to say it's on the side of the engine block on the driver's side.

Thats what i did.

Yes it has a knock sensor but im running an 88 ecm.

 

[franklin2]

You are correct. The 86 has the sensor hooked to a yellow/red wire and going to pin 23 on the computer. 1988 does not have a pin 23 in the diagrams. And of course no knock sensor hooked to it.

 

[bobbywalter]

and also has a more aggressive non egr timing table.

 

[rusty ol ranger]

and also has a more aggressive non egr timing table.

Really? I thought the earlier trucks ran a hotter timing table because the knock sensor could correct?