Car Won't Start, Fuel Delivery - PSI Harness
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Car Won't Start, Fuel Delivery - PSI Harness
Ok, I got a PSI harness and tuned computer on an LS1. I have a sumped tank with a brand new fuel pump.
A few days ago I attempted to start the car and a fuel line burst, so I replaced the line. I bumped my hand on the fuel pump ground and pulled the wires apart. I regrounded it (the pump is grounded directly to the battery).
Since the IGN and FUEL relays are the same, I tried swapping them, nothing. Also, for ***** and giggles, I ran a noid light on the Injectors, no light.
I confirmed every ground on the car, I checked power to the EFI fuse box. It's all good (12v bat and 12v switched). I cranked and checked to see if there was 12v going to the fuel pump, it's a no go.
Is it possible for 2 new relays to go bad at the same time? I've checked absolutely everything I can think of... I've searched ls1tech and pro touring for the past 4 hours, I can't find anything.
Maybe it's my computer? The packaging it came in was badly damaged, but I figured they were supposed to be able to take a beating...
A few days ago I attempted to start the car and a fuel line burst, so I replaced the line. I bumped my hand on the fuel pump ground and pulled the wires apart. I regrounded it (the pump is grounded directly to the battery).
Since the IGN and FUEL relays are the same, I tried swapping them, nothing. Also, for ***** and giggles, I ran a noid light on the Injectors, no light.
I confirmed every ground on the car, I checked power to the EFI fuse box. It's all good (12v bat and 12v switched). I cranked and checked to see if there was 12v going to the fuel pump, it's a no go.
Is it possible for 2 new relays to go bad at the same time? I've checked absolutely everything I can think of... I've searched ls1tech and pro touring for the past 4 hours, I can't find anything.
Maybe it's my computer? The packaging it came in was badly damaged, but I figured they were supposed to be able to take a beating...
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I confirmed all the fuses are good, I pulled each individually and checked.
The power is good, inside and out. I'm tapped into a fused (30a) 12v on my AAW harness, I checked power at both the AAW harness and the PSI harness, good.
Does the PCM still controll the fuel pump, even if it's relayed?
The power is good, inside and out. I'm tapped into a fused (30a) 12v on my AAW harness, I checked power at both the AAW harness and the PSI harness, good.
Does the PCM still controll the fuel pump, even if it's relayed?
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Yes.. The PCM controls the relays on/off switch. The on/off switch then lets the power flow through. Did you try to communicate with the pcm? Maybe a simple battery disconnect may help.
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How can I communicate with the PCM? Is their a way to check to see if it died/is malfunctioning?
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What you should check for is power to either terminal 85 or 86 on the fuel pump relay. Easiest thing to do is just use a multimeter across those two terminals. with the key on it should have 12v for about 2 seconds for the fuel pump prime. then it should be hot at all times when cranking and running.
The pcm controls the 12v to the fuel pump relay.
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This is the most common mistake that people make.
What you should check for is power to either terminal 85 or 86 on the fuel pump relay. Easiest thing to do is just use a multimeter across those two terminals. with the key on it should have 12v for about 2 seconds for the fuel pump prime. then it should be hot at all times when cranking and running.
The pcm controls the 12v to the fuel pump relay.
What you should check for is power to either terminal 85 or 86 on the fuel pump relay. Easiest thing to do is just use a multimeter across those two terminals. with the key on it should have 12v for about 2 seconds for the fuel pump prime. then it should be hot at all times when cranking and running.
The pcm controls the 12v to the fuel pump relay.
The wire I'm running power to the fuseblock is always hot, it's confirmed on my AAW harness printout. I ran a multimeter over it several times just to be sure.
Like I said, before, when I FIRST tried to start it (that one time), the fuel pump primed (and shot fuel out, had to replace the fuel line), now that I've replaced it and fixed the ground, I'm getting nothing electrically. No fuel, no injectors, no Malfunction Light, etc. I've confirmed power to the harness, and checked all grounds.
I'm seriously pulling my hair out wondering what it could be.
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I tried that, I checked each individually, the hot wire is hot (12v) and the fuel pump wire is cold (no signal).
The wire I'm running power to the fuseblock is always hot, it's confirmed on my AAW harness printout. I ran a multimeter over it several times just to be sure.
Like I said, before, when I FIRST tried to start it (that one time), the fuel pump primed (and shot fuel out, had to replace the fuel line), now that I've replaced it and fixed the ground, I'm getting nothing electrically. No fuel, no injectors, no Malfunction Light, etc. I've confirmed power to the harness, and checked all grounds.
I'm seriously pulling my hair out wondering what it could be.
The wire I'm running power to the fuseblock is always hot, it's confirmed on my AAW harness printout. I ran a multimeter over it several times just to be sure.
Like I said, before, when I FIRST tried to start it (that one time), the fuel pump primed (and shot fuel out, had to replace the fuel line), now that I've replaced it and fixed the ground, I'm getting nothing electrically. No fuel, no injectors, no Malfunction Light, etc. I've confirmed power to the harness, and checked all grounds.
I'm seriously pulling my hair out wondering what it could be.
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The problem is that the fuel pump wire will only be energized for a couple seconds when the car is NOT running. The PCM doesn't let the fuel pump keep getting power if it senses that the car is not running. So if you are turning the key forward to "run" position (not start) and then walking back to your meter to see it, it is probably already cycled the power back to off by time you get to it. Can you get someone else to cycle the key while you are right in front of the meter?
From what I understand, they kill power to the fuel pump in 2 seconds because they don't want fuel to be fed in the event of an accident. I also have to believe that the injectors won't get power unless the car is running (or starting?) as well. My guess is that they wouldn't want the rest of the fuel line to bleed out through the injectors. Just a guess though, but maybe that is why you aren't seeing power at the injectors either.
The thing that really confuses me with the whole thing is that you had fuel the first time.
What is the PSI kit number?
What is the AAW number?
Last edited by 66 BADBOY; 10-07-2012 at 06:53 AM.
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Also, reading the PSI instructions online, it said not to disconnect the battery with the key in the run position because it could damage the PCM. How did you disconnect the battery?
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I'm not sure if you exactly caught what was said earlier, so I'll try to help by clarify what green was saying. Make sure that the wire feeding the fuel pump relay is a source that is always on when the key is forward and also in the "start" position. Accesory fuses are NOT on during a start (radio, heater, etc). For what you are doing, you should be tapped into a pink wire (on a stock harness. But with PSI, it looks to be a red wire) for run/start power.
The problem is that the fuel pump wire will only be energized for a couple seconds when the car is NOT running. The PCM doesn't let the fuel pump keep getting power if it senses that the car is not running. So if you are turning the key forward to "run" position (not start) and then walking back to your meter to see it, it is probably already cycled the power back to off by time you get to it. Can you get someone else to cycle the key while you are right in front of the meter?
From what I understand, they kill power to the fuel pump in 2 seconds because they don't want fuel to be fed in the event of an accident. I also have to believe that the injectors won't get power unless the car is running (or starting?) as well. My guess is that they wouldn't want the rest of the fuel line to bleed out through the injectors. Just a guess though, but maybe that is why you aren't seeing power at the injectors either.
The thing that really confuses me with the whole thing is that you had fuel the first time.
What is the PSI kit number?
What is the AAW number?
The problem is that the fuel pump wire will only be energized for a couple seconds when the car is NOT running. The PCM doesn't let the fuel pump keep getting power if it senses that the car is not running. So if you are turning the key forward to "run" position (not start) and then walking back to your meter to see it, it is probably already cycled the power back to off by time you get to it. Can you get someone else to cycle the key while you are right in front of the meter?
From what I understand, they kill power to the fuel pump in 2 seconds because they don't want fuel to be fed in the event of an accident. I also have to believe that the injectors won't get power unless the car is running (or starting?) as well. My guess is that they wouldn't want the rest of the fuel line to bleed out through the injectors. Just a guess though, but maybe that is why you aren't seeing power at the injectors either.
The thing that really confuses me with the whole thing is that you had fuel the first time.
What is the PSI kit number?
What is the AAW number?
By nothing, do you mean it would turn over but not start? Or do you mean it would not even turn over?
Also, reading the PSI instructions online, it said not to disconnect the battery with the key in the run position because it could damage the PCM. How did you disconnect the battery?
Also, reading the PSI instructions online, it said not to disconnect the battery with the key in the run position because it could damage the PCM. How did you disconnect the battery?
I turned off everything and turned the key off before pulling the NEG cable then the POS cable.
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I have an idea, why not call the people who sold you the harness and get tech support. Surely they would be able to trouble shoot their own product as they know what color wires they use and what voltages should be where.
They are a paying sponsor and jump on just about every wiring issue in this section.
They are a paying sponsor and jump on just about every wiring issue in this section.
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I have an idea, why not call the people who sold you the harness and get tech support. Surely they would be able to trouble shoot their own product as they know what color wires they use and what voltages should be where.
They are a paying sponsor and jump on just about every wiring issue in this section.
They are a paying sponsor and jump on just about every wiring issue in this section.