Fuel delivery/pump issue
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CF Beginner
Joined: Dec 2018
Posts: 3
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Fuel delivery/pump issue
I’m finally getting around to trying to get my 05 trailblazer running again. Been working with a no fuel issue. It died when accelerating and wouldn’t restart. No fuel pressure so I put a new pump on it. It ran for about an hour (very rough) and then wouldn’t restart. Towed it home. Would restart but not stay running. Fuel pressure would be chaotic and vehicle would die after a few seconds. Eventually led to no start at all. I wasn’t getting 12v to prong 85 of the relay from pcm control. Changed the pcm with a preprogrammed pcm. I’m still not getting proper voltage to pcm control side of the fuel pump relay (85). I have already changed the fuel pump and the pcm. I have a good ground (86) at the relay and proper voltage thru the fuse beside it (prong30). Any ideas or suggestions?
CF Monarch
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
This is either on or off circuit. Re-cap, you've swapped relay, cleaned base, same issue, replaced pcm. Reading voltage at the relay, reading voltage at the pump, relay, with the same ground point? Swap either the horn or a/c relay with fuel pump relay just to totally (almost) rule that out as an issue.