Major misfire, all new plugs, leads, cap, rotor. Timing correct. Spider Inj suspect?

[ChromedZ71]

I have a 1998 GMC K1500 with the 5.7L Vortec. Just today I started having some misfiring happening. I pulled my spark plugs and saw 3 had cracked porcelain, so I replaced all 8 with E3 Racing plugs. Leads with NGK performance, and cap and rotor with OEM.

That made my issue worse. The misfire is now considerable and I cannot drive my truck with it. Only DTC that came up was a P0300 - Random Misfire. I talked to a friend who said it is most likely the spider injection having issues (therefore it probably needs replacing).

I did some research and the symptoms my truck has looks like either a fried PCM or a bad Spider injection system.

Most noticeable symptoms are:

Misfire, very strong, shakes the whole truck every rotation of the crank.
Smell of raw fuel out the exhaust, very strong and almost intoxicating.

PLEASE HELP!! I'm moving in a week and need to get my truck almost 200km from where it is currently parked...

 

[badazzbulldog]

spider is gone no question about it

 

[woody31]

the e3 plugs aint helping either,,pull those and run what gm calls for,,change the spider,,and enjoy your truck,,

 

[SAATR]

Check and see if you have weak spark first. The tools aren't expensive and can be had at most parts stores. You'll get a strong fuel smell with poor spark, as the fuel is being injected but not burned. Not to mention that it isn't hard to swap on a known good coil or module to verify. I say all this because you also mention that it got worse with new components, which wouldn't be the case with a spider issue.

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[badazzbulldog]

look down the throttle body with a flashlight I would almost guarantee you'll see a wet clean area in there.

 

[ChromedZ71]

I have run the E3 spark plugs in all of my vehicles (on number 10) and always had good results, they have efficient spark and have thus far improved fuel economy (except in this instant where the engine has been having issues before being able to drive).

I have a spark plug light (hooks up between plug and lead and lights when sparked). I will try that, I've been meaning to upgrade the coil to an MSD coil, as well as an MSD distributor (after the currently new cap and rotor are thru their life), so I will pick up a new coil tomorrow and see what happens. Hopefully it is just a coil, I don't know if I can afford a new spider system. You make a good point SAATR.

Will keep this updated as I test.

 

[SAATR]

I would stay away from the MSD coil and just use a Delco or equivalent. My experience with MSD's offshore stuff isn't favorable.

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[ChromedZ71]

Alright. Duly noted. I'll pull my intake off and take a peek. I'm assuming that if there is a wet, clean area that it is my spider system?

 

[SAATR]

Yeah, generally under the main body if it is leaking, or possibly just the FPR if it is leaking. It will be obvious, as the rest will be covered in black grime.

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[ChromedZ71]

So, looked in the tb. Looks all black and grimey except for a smaallllll little strip.

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