No start issue.. I'm stumped

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04Duramax

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So long story short.. I had to replace my OEM fuel pump after it started to make the high pitch whine. The replacement unit is a AEM 320 High flow pump from Schnitz racing. While I had the tank off and such I decided to replace the plugs (with NGK Iridium plugs gasped at .30 and added the PAIR block off plates and plug (also from Schnitz). Finally I flushed the coolant system and changed the oil. So with all of that being done I went to start the bike and instantly blew the 10A Fuel Fuse (under the Left side dash piece). I tore everything apart and found a pinched wire during reassembly. Now that that problem was repaired the pump now primes (as far as I can tell since there is no where to take a pressure reading but a ton of fuel shoots out).. but the bike still won't start. I know I have spark since I pulled them out and checked them so I'm sure it's still a fuel issue.

My question is.. does anyone have any other ideas as to what might be causing my no fuel issue? This is driving me insane! I'm just hoping there is possibly another fuse blown that I haven't found.

I have power to the Tri-plug at the pump on the yellow wire with red chaser but it seems.. and the ground is good.. but I never get power or anything else to the third wire (red with black chaser)….. I'm hoping someone can drop a knowledge bomb on me.. my ride has been down for almost three weeks waiting on parts and so on.. it's killing me!
 
Shoot GixerHP a PM... he may be able to shed some light on it.
 
You said it was shooting fuel out , so I will assume the pumps working. Was this fuel being squirted through the injectors or just the line to the fuel rail ? I'm not saying you ruined the plugs, but word is you don't gap iridium plugs because the gauge kills the plug. They come gapped anyways. Best of luck.
 
I have fuel to the injectors. I bench tested all of the injectors today and they all spray… Like I said I'm stumped. I don't have the tools though to check the pressure. I did do a flow test which the manual has in it and it passed that with flying colors. Pretty sure the plugs are GTG, I use a special pry tool to open them up slightly since they were not gapped correctly. Also bench tested the plugs as well and they all sparked. Also checked all of the relays, connectors, grounds and fuses…. still nothing solid to go off of.
 
How about some starting fluid in the throttle body's ???

If it starts then you would know it's not electrical. If it doesn't start the it may be something electrical.
I assume you checked the battery voltage and it's fully charged, right?
 
Voltage to the batt is good… no other mods.. Kill switch is also good lol… It turns over really good just no fire.. ugh.. this is starting to irritate me..
 
Last time I did an aem pump I was cussing. Lots of trimming and modifying. Lots of places for mistakes. If it was not done properly you could be losing pressure before it reaches the injectors. Or if you have the positive and negative backwards then the pump will run backwards and not make pressure.
Either pick up a fuel pressure test kit or maybe borrow the pump assembly from one of your friends bikes to test with?
 
1bondoman said:
Last time I did an aem pump I was cussing. Lots of trimming and modifying. Lots of places for mistakes. If it was not done properly you could be losing pressure before it reaches the injectors. Or if you have the positive and negative backwards then the pump will run backwards and not make pressure.
Either pick up a fuel pressure test kit or maybe borrow the pump assembly from one of your friends bikes to test with?
Click to expand...

Yeah not exactly the direct fit they claim it to be. I made sure all of the ports were clear as it's indicated on the instructions.. and connections are right.. I'm trying to track down the pressure tester fittings now..
 
Don't need fittings. Just hoses and clamps.
Plus there is a small plastic piece that holds grommet in fuel pump housing. Are you sure you put it back?
 
If the pressure is over or under 43 psi, the bike ill not fire, its a failsafe. You need to test the pressure just to be sure.
As for the starting fuild, if the pressure is low, and the bike sputters. There is a problem with he regulator installation.
If still does not start, you then MUST know if the pressure is correct!
 
are the plugs wet or dry after trying to start? is there spark at the plug; pull one out and ground it and crank it over to identify if spark or fuel is the issue. mine wouldn't start and after hours of searching found out the pc3 was not opening the injectors. unplugged the pc3 and it fired right up. if you have a pc3/5 then unplug it and see if the bike starts. try the above mentioned starting fluid first as it's easier. that's what i did and helped identify a fuel issue.
 
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