Misfire! 1998 K2500 5.7

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Jrgunn5150

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Pigpen is misfiring, worse since I changed the distributor.

It was running along fine, and then it would briefly cut out. Now, it's clearly not running on all cylinders.

Data scanning pointed me to cylinder 3, unhooking that wire did not change the idle quality. Pulling the plug, it was not wet or forced in anyway, and was sparking correctly.

So, have I just found a stuck poppet? I've never had one stick closed, they usually stick open or the lines crack and the truck runs rich.
 

Biggershaft96

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I dont know how to check to see if one is clogged but it sounds like that or the timing is still off. Did you make sure all the wires are on the right plugs? Ive ran into that before.
 

Jrgunn5150

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I dont know how to check to see if one is clogged but it sounds like that or the timing is still off. Did you make sure all the wires are on the right plugs? Ive ran into that before.

Three or four times now lol. But that, in theory, would give me two misfires, and I only have the one cylinder misfiring really.
 

Jrgunn5150

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Well that aint it then. I guess the only thing left would be the spider since its still got spark

That seems logical to me also, it just drives me nuts that it didn't do it before and now it is lol. I'll have to go out there and pull the cap and see if it's screwed up somehow
 

Jrgunn5150

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I did, that and the rotor are new with the distributor, but, maybe the shop bungled it somehow.

It wasn't running right before, but it wasn't consistently, constantly not firing number 3 either. When I first got it back, it would run well for brief seconds, now it just doesn't ever fire number 3 at all.

I'm unsure of how the PCM reads a misfire in a specific cylinder, since there's no coil pack.
 

SAATR

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I did, that and the rotor are new with the distributor, but, maybe the shop bungled it somehow.

It wasn't running right before, but it wasn't consistently, constantly not firing number 3 either. When I first got it back, it would run well for brief seconds, now it just doesn't ever fire number 3 at all.

I'm unsure of how the PCM reads a misfire in a specific cylinder, since there's no coil pack.


Crank acceleration rate as read from the crank position sensor. It can tell based off of the frequency of the square waveform.

Sent from my XT1585 using Tapatalk
 
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