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98 Chevy K1500 Z71 - possible vacuum leak or other issue?

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Old 06-24-2019, 06:38 PM
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With the car off, it'* sitting at 12.22v.
Old 06-24-2019, 07:06 PM
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Should be above 12.5V when fully charged. Best to see what the voltage is while it'* cranking. Should be 10.5V minimum.
Old 06-24-2019, 07:48 PM
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Could the lower voltage be from getting it to turn over and not starting? Or maybe the alternator failed? Kinda nervous about running it after the misfire code.
Old 06-24-2019, 08:16 PM
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Voltage idling is 13.8. No drops in voltage with accessories.
Old 06-25-2019, 08:47 PM
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I did a fuel pressure test today and it is sitting at 58-60psi on a 600rpm idle. The idle seems more stable today, still drops lower occasionally, especially after a rev. When revving, fuel pressure drops to 52psi.
Old 06-25-2019, 09:40 PM
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Had a look at some sensors. The TPS looks new. Replaced the IAC because it was covered in carbon. I have a MAF in box. Still hunting for vacuum before I do that one.
Old 06-26-2019, 01:52 PM
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Pulled some spark plugs on my lunch break. 1 is oil fouled gapped 0.64. 8 is carbon fouled gapped 0.64. 7 is carbon fouled and gapped 0.52. The MAF is clean.
Old 06-27-2019, 12:43 PM
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Sounds like you're headed the right direction. Definitely replace spark plugs.

How recently did the previous owner rebuild the engine?

What was the problem with it that compelled the rebuild?

How many miles on the chassis?

How many miles since the rebuild?
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