CK5
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Black Betty - Formerly Blaze the Monster Machine

1984 K5 Project for Dad and kids
So where in the Holley harness would I grab a clean 5v and ground without tapping off of the current ones? Looking at the wiring diagram it looks like they’ve got a few sensors tapped off those lines.
 
I bet that hose let go again.
Go to O'Reilly or something and get submersible fuel injection hose.
Expensive as hell, and should say "submersible" on it iirc. It's the only thing that will work in the tank. Except the piece that comes with the pump sometimes
 
The liner alone may not hold pressure, and I'm not sure why, but normal black fuel hose has gas in it all day long and is fine. But cannot be submerged in it constantly.
So that may be the same way :dunno:
 
So where in the Holley harness would I grab a clean 5v and ground without tapping off of the current ones? Looking at the wiring diagram it looks like they’ve got a few sensors tapped off those lines.

You have to look at the pinout to see what's available, but sometimes you need to splice into one. If so I use solder and heat shrink, in a place that won't flex often.

if you are talking about fuel pressure sensor they often have a connector in the harness ready to go for fuel and oil pressure.
 
Took it out for the first time in a couple of weeks. Running great. Tune was dialing in nicely. Go to move it to take the Camaro and no fuel pump. Relay is clicking but no pump. Checked fuses and they are good. I don’t have a clue. Guess I’ll pull all the wires out and see if there’s a short somewhere but I’d be surprised if there was. I’m kinda lost on this one.
 
Is this the new pump or still the first one?

Did you test run the pump at the connector?
 
New one. I test ran it at the connector after I installed it and I’ve driven it three times since then. Today I backed it in the driveway to park it, went outside a couple of hours later and nothing. I’m wondering if the weather pack connector I’ve got on it is a loose connection or something. I dunno. That’s tomorrow’s issue. Tonight’s issue is beating the vanilla dome on super Mario bros with my kids.
 
Truck turns over fine and has 12.5v with the key on. But it’s not even priming with the key turned on.
 
If the ECU is not on, it won't prime the fuel pump, double check for voltage at the ECU on trigger or just look at the LEDs

You can also obviously apply 12V directly to the fuel pump and see if it works. Those Walbros are usually very reliable.
 
ECU is on. LED’s are on. Fuel pump relay is triggered by the fuel pump wire from the ECU and it’s clicking on and off. I can crank it and the ECU will sync with the distributor and start reading RPM’s. It’s not the Terminator. After lunch I’ll have time to check and make sure I’ve got voltage leaving the relay and then check the weather pack and make sure voltage is going through that. If I do then I’ll run a wire straight to the harness from the pump hanger and see if it kicks it then. If that doesn’t work I’ll pull it out and put power straight to the pump.

There’s not many failure points. As long as voltage is coming out of the relay, it’s either at the weather pack connector, the connector on the pump hanger, or the pump itself.

I doubt it’s the fuel hose blowing out like last time as I changed it to the one Heath recommended and I can’t hear the pump running at all.

Long shot here but maybe I need to adjust the regulator to drop the pressure down to maybe 50psi instead of 60? Maybe 60 is to much?
 
You could pull the relay and jumper 86 to 87 if pump runs the wiring is good. Then maybe relay
 
It’s a brand new Walbro. It’s got maybe 10 miles on it. Same with the last pump (think it was an edelbrock). That one lasted almost 200 miles.
 
ECU is on. LED’s are on. Fuel pump relay is triggered by the fuel pump wire from the ECU and it’s clicking on and off. I can crank it and the ECU will sync with the distributor and start reading RPM’s. It’s not the Terminator. After lunch I’ll have time to check and make sure I’ve got voltage leaving the relay and then check the weather pack and make sure voltage is going through that. If I do then I’ll run a wire straight to the harness from the pump hanger and see if it kicks it then. If that doesn’t work I’ll pull it out and put power straight to the pump.

There’s not many failure points. As long as voltage is coming out of the relay, it’s either at the weather pack connector, the connector on the pump hanger, or the pump itself.

I doubt it’s the fuel hose blowing out like last time as I changed it to the one Heath recommended and I can’t hear the pump running at all.
I think you are on the right track.

Long shot here but maybe I need to adjust the regulator to drop the pressure down to maybe 50psi instead of 60? Maybe 60 is to much?

I wouldn't worry about that, the pump could supply 90 psi or more, it just loses some flow at higher pressure.

However, what injectors did we get you? You may not need 58, 43 or 50 might be plenty for your engine and less current draw on the system. I don't think that's your problem, its probably a bad connection somewhere, but if it's not needed no point it doing it anyway.
 
It’s a brand new Walbro. It’s got maybe 10 miles on it. Same with the last pump (think it was an edelbrock). That one lasted almost 200 miles.

The 2nd one is a genuine USA made Walbro 255 lpg, I'd be surprised if that is bad, but its not impossible.

The 1st one was a chinese Accel 340 lph pump because we couldn't get a genuine one at the time.
 
I think you are on the right track.



I wouldn't worry about that, the pump could supply 90 psi or more, it just loses some flow at higher pressure.

However, what injectors did we get you? You may not need 58, 43 or 50 might be plenty for your engine and less current draw on the system. I don't think that's your problem, its probably a bad connection somewhere, but if it's not needed no point it doing it anyway.
They are edelbrock injectors rated at 43psi. It’s just an NA 383 so they aren’t that big.
 
Huh. Jump the relay and pump kicks on. Reconnect relay and turn key and pump primes. I’m wondering if something is heat soaking somewhere but not sure what. ECU is mounted in the glovebox. Maybe the relay but it’s pretty far away from anything.
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