Massive hesitation, SES light flashing :(

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nimrod.sixty9

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I know SES flashing is usually a missfire. My worry... is it likely caused by the spider injection? That, from my understanding, is known to have issues.

I have a '99, I could only imagine it has the newest style considering they went with the LS the very next year. Would I be right?

Aside from the codes, where would you start? Replace plugs, or go stright for pulling the intake?

Ill get the code/s later tonight.
 
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nimrod.sixty9

nimrod.sixty9

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Code is P303. Missfire cyl 3.

Truck still runs like poo at all speeds, including idle. Flashing seems to only happen when getting into the pedal or going over bridge.

Is this spider injection? Intake gaskets? Plug? Wires?

Where to start?
 

SunlitComet

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Does not mean usually, IT IS LIVE ACTION MISFIRE.

---------- Post added at 09:51 PM ---------- Previous post was at 09:50 PM ----------

And as I mentioned start by reading your plug.
 
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nimrod.sixty9

nimrod.sixty9

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Does not mean usually, IT IS LIVE ACTION MISFIRE.

---------- Post added at 09:51 PM ---------- Previous post was at 09:50 PM ----------

And as I mentioned start by reading your plug.

What do you mean by live action? I want to be sure cause it is not consistent. The rough running is, but when its flashing, its a whole lot worse.
 

BRUTUS_T_HOG

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Unload that shotgun.....

You have a continuous misfire at all speeds. START with a compression test to verify engine mechanical condition before wasting time on throwing parts

If you have good compression across all cylinders, a shorted distributor cap or other ignition system trouble is far more common than a failed CPSFI assembly
 
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nimrod.sixty9

nimrod.sixty9

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Of course now I get a better look today; I notice water/coolant on the intake around the thermostat housing and rear of the compressor. Look in rad and I cant see anything. GF said she never saw the temp go up... FML

Mostly dry, weee bit wet.

2013_08_09_445_e5171824c5e43a92905c.jpg


I should also note the plugs were miss-gapped when I got the truck. I regapped them then. Now that I think of it, I believe the truck had a misfire code when I got it. That's how I discovered the miss-gap. Been fine for two years...
 
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SunlitComet

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what is the plug wet with. And check any connectors related to the two speed sensors that are flaking out to see if they are dirty if not replace them. Those are not dirty "sensor head" issues. BUT FIRST AND FOREMOST.......

How the hell did you get C**** codes on the scan xl package. Were you connected logically to the PCM or something else. Even Palmer says it likely would not work.
 
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nimrod.sixty9

nimrod.sixty9

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what is the plug wet with. And check any connectors related to the two speed sensors that are flaking out to see if they are dirty if not replace them. Those are not dirty "sensor head" issues. BUT FIRST AND FOREMOST.......

How the hell did you get C**** codes on the scan xl package. Were you connected logically to the PCM or something else. Even Palmer says it likely would not work.

Cyl Comp
1.....170
3.....150
5.....180
7.....180

Give or take


I coulodnt tell what it was wet with. Just a little near the thread area. Otherwise it looks like cyl 1 and cyl 5 and 7 look simular. Basically, 1 and 3 match and 5 and 7 match. Ill take pics soon.
 

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