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Old 04-02-2013, 03:23 PM
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rodneym rodneym is offline
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Cobra Make, Engine: KMP 427 S/C, Twin Paxton 511 FE
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Default Fuel Pressure spike

I went for a drive the other night and I noticed that my fuel PSI gauge jumped from 5.5 to almost 15, then ran like shiz until I cleared its throat. I tapped the gauge thinking it was faulty but it wasn't budging. Then I shut off the pump and it read zero and I turned it on again. I was fine for a minute, then the same thing happened. I wanted to look at the gauge on my fuel log but it was too dark in that area (Note to self: flashlight in the toolbag). I went home carefully. Luckily I was still close.

I've got a Holley Black at the tank and a filter right after it. Then it makes the long trip to the firewall where the regulator is, then to the rear part of the log (from the firewall, not from the front like with a mechanical pump). At first I thought it may be a stuck needle but one out of 4 (dual quads) wouldn't cause that spike, right? So I figured the regulator must be failing. I ordered a replacement diaphram and I'll fix it in the next couple days.

I think that the regulator was failing, causing high pressure in the carbs, blowing the needles and dumping fuel causing the 'almost' stall condition.

How does my diagnosis sound? What am I missing?
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