Help. Ijnjectprs aren't firing
Thread Starter
Teching In
Joined: Jun 2019
Posts: 10
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Help. Ijnjectprs aren't firing I need help,
i have a 2004 5.3 with a CBM 450 cam, and blue springs. I have an LS2 intake with a CMB adaptor plate to a dbw truck throttle body. My harness is a CBM. The throttle works , I have had my blue / green computer flashed. Engine will not run. If I " prime" the manifold it will fire right up, and burn off the fuel, then quit. I have 12v to all 8 injectors. I have 12v at the blue connector for all 8 injectors. I don't know what to do , any help Is appreciated
i have a 2004 5.3 with a CBM 450 cam, and blue springs. I have an LS2 intake with a CMB adaptor plate to a dbw truck throttle body. My harness is a CBM. The throttle works , I have had my blue / green computer flashed. Engine will not run. If I " prime" the manifold it will fire right up, and burn off the fuel, then quit. I have 12v to all 8 injectors. I have 12v at the blue connector for all 8 injectors. I don't know what to do , any help Is appreciated
Check your crank position sensor. I had that problem on my ls6. Was a brand new sensor from summit and it was bad. Easiest way to tell without hooking up an oscilloscope is to see if you have a tach signal. Mine wasn't showing a tach signal while cranking then I replaced it with a 15 year old sensor and cranked right up
Thread Starter
Teching In
Joined: Jun 2019
Posts: 10
Likes: 0
Check your crank position sensor. I had that problem on my ls6. Was a brand new sensor from summit and it was bad. Easiest way to tell without hooking up an oscilloscope is to see if you have a tach signal. Mine wasn't showing a tach signal while cranking then I replaced it with a 15 year old sensor and cranked right up
i replaced the crank sensor that came with the engine with a brand new Delphi " just to be sure". I'll put the original in, and give that a try
Could also be the security system. It will allow the engine to run about 1 second and die.
If it's not that it's a cam or crank sensor issue. The computer flashes the ground to the injectors to fire them. So you can hook up a noid light and watch for injector fire or use a test light on the ground wire at the injector plug and watch for it to flash.
If you have a graphing meter ( I use a fluke ) you can tap into the signal return wire at the cam and crank sensor and watch for the graph to flash. The signal is too fast for the numbers on the screen, that's why you need an oscilloscope to watch the wave form pattern, or a graphing meter. Oscilloscopes are several thousand dollars, but a graphing meter is a couple hundred so I bought a graphing meter for that reason (to watch cam and crank sensor signals).
If it's not that it's a cam or crank sensor issue. The computer flashes the ground to the injectors to fire them. So you can hook up a noid light and watch for injector fire or use a test light on the ground wire at the injector plug and watch for it to flash.
If you have a graphing meter ( I use a fluke ) you can tap into the signal return wire at the cam and crank sensor and watch for the graph to flash. The signal is too fast for the numbers on the screen, that's why you need an oscilloscope to watch the wave form pattern, or a graphing meter. Oscilloscopes are several thousand dollars, but a graphing meter is a couple hundred so I bought a graphing meter for that reason (to watch cam and crank sensor signals).
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Verdad Gallardo yeah you may see it in a scanner, you said you were gonna hook up the original tach and check for signal, I thought you meant you were gonna watch the tach itself.
