Yeah, sensor in the dist is just for injector timing, has nothing to do with ignition. Probably no way to tow it without paying either huh? Wonder if a parts store would let you 'rent' a code reader..... see if the PCM thinks its getting signal from the various sensors....

 

For what it's worth, when my pcm went out it was giving me a no spark I don't know episodes for week before it finally killed off and gave me a nobus

 

yeah i am at a loss the only time i ran into a bad PCM. It threw the nobus code.

And as far as towing it i dont have another truck or trailer and cops are insane so a tow strap is a no go. would a regular scanner work like the ones that just read codes. or does it have to be one that can read injector pulses and spark?

 

I hate to condemn a PCM unless I'm positive it has failed.

Without live data, and you'd need a scanner capable of reading that data not just a code reader, you can't tell what is going on.

It's possible the new crank sensor has failed.

If you have 12 volts to the coil the ASD relay is energized, by the PCM. The coil driver could have failed.

 

i am not getting the signal from the pcm to the coil.
I just tested the crank sensor and it is sending the 5volt signal and it is getting to the pcm.
I am trying to figure out if the asd relay could be bad is there a way to test those. i have placed 4 differnt ones in there. (all same part number just from another truck) so i doubt it but i am at witts end

 

ASD supplies the 12 volt side of the coil. Did you use a high frequency voltmeter across the wiring harness for the coil? Should be able to probe both sides, and show 12 volts.

500 RPM idle = 250 firing sequences in 60 seconds = 4.16 fires per second = 0.24 seconds between fires.

500 RPM = 8.33 RPS = 3,000 degrees per second = 0.000333 of a second per degree @ 10 degree dwell time = 0.0033 seconds dwell

So you should see 12 volts across the coil connector AT LEAST every 0.24 second for 33 ten-thousanths of a second. Or if you have a frequencing meter like I do, it should register 12VDC at a frequency of 300 or so Hz.

 

The ASD relay also feeds the injector circuit, again the PCM switches the ground side.
It also feeds the O2 heater's.

 

ok so i am stuck again would me having bad connection on my 02 sensor make it not have spark????

 

Dan meant that the ASD feeds the heaters, not the PCM.

The ASD- Auto Shutdown Relay- powers the O2 heaters, the fuel pump, the coil, and probably a dozen other things (Dan has the full list). Basically, as implied by the name, turning off that one relay shuts down every aspect of electrical circuits related to the engine in one hit. This is done mainly so that in the event of an accident, everything that can cause a fire gets shut off in one swift move.

Something to look at- check the TPS connector, make sure you have 5 volts there.

 

Thanks Magnet for clarifying that. The o2 heaters should not affect the ignition.

Do you have a noid light? Are the injectors pulsing?