no spark at coil - what to check??

[kunar]

well it broike down on the way to work, died without warning. i checked for spark real quick and it doesnt have any at all. ive checked grounds and stuff like that but didnt notice anything. im at work now and will be working on the truck on lunch. i just need some suggestions on what and where to spend my time.

 

[Psychopete]

Make sure it's getting power and that the rotor is turning in the distributor. Is the PCM getting powered?

http://www.therangerstation.com/tech_library/TFI_Diagnostic.html

Pete

 

[90B24wd]

It could be your TFI module.

 

[kunar]

my first thought was TFI, but now that ive had a chance to look at it, it looks like the computer isnt getting power, or has crapped out. i dont hear a fuel pump when i turn on the key and thers no fuel pressure. i dont have hardly any tools, and none of my usual spare parts, they are all at home and im still at work. ill go get a relay and try that, should be cheap and its really all i can do till i get a ride home to grab some tools.

 

[kunar]

it wont let me pull codes either, i plug in the reader and the led stays on solid

 

[kunar]

i replaced the computer and the relay both with no luck. i can hear a realy clicking when i turn the key but i dont know for sure what one it is. i dont hear the fuel pump prime like it should either.... i think my next try is the tfi module. i dont know if it would kill the fuel pump too or not, but i dont know what else to try right now.

 

[IMenriched]

I ended up putting in a new pick-up coil....not saying that your's is bad....but I left the key on during my diagnosic time and unplugged the TFI and every time I replugged it in...I heard the FP prime up.

My TFI was bad too...once I knew that was good ...pretty much knew that I had to dig deeper.

from that, I conclued that the TFI had a FP control feature/element. start with TFI and the ignition relay...if that don't get spark then you might have to dig into the pick-up coil, this is on a 86'....there maybe differences...IDK

 

[Psychopete]

Have you verified that the PCM is getting power? PCM controls fuel pump relay. You might be hearing the ECC relay clicking, but not the fuel pump relay. You might check the fuse link to the PCM before going through the hassle of tearing into the distributor, definitely make sure you have power there. Anyway to verify that your injectors or IAC are getting power? They're hot all of the time with the key on (see wiring diagram).

If you don't have anything on pin #1 to the computer at the yellow wire - it's more than likely the fuse link. If you have power there, but not at the injectors, I would take a closer look at the ECC relay.

Pete

 

[kunar]

Have you verified that the PCM is getting power? PCM controls fuel pump relay. You might be hearing the ECC relay clicking, but not the fuel pump relay. You might check the fuse link to the PCM before going through the hassle of tearing into the distributor, definitely make sure you have power there. Anyway to verify that your injectors or IAC are getting power? They're hot all of the time with the key on (see wiring diagram).

If you don't have anything on pin #1 to the computer at the yellow wire - it's more than likely the fuse link. If you have power there, but not at the injectors, I would take a closer look at the ECC relay.

Pete

you got it pete! it ended up being the power to the eec relay. it was not the fusible link, but the wiring before it. it was cracked and broken inside the insulation. i replaced it with a temp fix (at 12:30 last night... ugh) with some wire and a fuse. its working now, ive already got 60 miles on it. ill fix it right tonight. i had to be to work at 6:30 this morning... i got about 3-1/2 hours of sleep last night


thanks again guys