Have spark but injectors won't spray. vats?
11-09-2008, 08:37 PM
#1
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Have spark but injectors won't spray. vats? Tonight I finally got my car to a point where it is ready to start. I spent most of the night checking over all the wiring and am positive it is wired correctly. I have spark on all cylinders, and pressure at the rail, but my injectors are not spraying. My ecu was retuned and the first thing I put on the list was to remove the VATS. Is there anything else I should look at before contacting the tuner who reprogrammed it?
11-09-2008, 09:41 PM
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how long has it sat, mine had 6 out of 8 injectors froze shut, take them out, soak them in alcohol, tap on them and put 12 volts to them, they will tick if they are working right, just like a solenoid.
11-10-2008, 08:21 AM
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Thats a good idea, I'll try that tonight. I checked that all of the pins at the injector plugs were grounded but did not check to make sure they were getting power. I'm going to run by radioshack also and pick up what I need to make a vats bypass.
11-10-2008, 09:34 AM
#6
?? Key on, should have 12v at 1 side.. The other side is not grounded, unless the engine is turning over/or running. And, only when that particular inj is being fired....
A noid lite is the proper tool to check for inj circuit operation @ the inj.
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11-10-2008, 11:24 AM
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11-10-2008, 11:52 AM
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98% of test lights arent very high quality and can have excessive resistance which in turn puts a greater load on the PCM and could mean a failure. A noid light is something that plugs directly into the injector harness and will blick every time the injector is commanded by the PCM. Noid lights were designed for injector testing so there is no harm in using them...very easy and efficient way of seeing if the electrical side of injectors is working
11-10-2008, 03:49 PM
#10
On The Tree
Just got my 07 5.3 into my 84 Silverado and I think I'm having a similar problem. I have spark at the plug, fuel at the fuel rail, but unknown in the injectors are firing. Harness was by current performance and program was by wait 4 me. Now i'm worried the anti-theft wasn't removed. Can u rent a noid test light or do u have to buy the kit?
11-10-2008, 04:33 PM
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Yes you could also use a piece of heater hose to tune your ear to the sound of the injectors ticking. If you have a multimeter and know how to use it, you can either put it on continuity or ohms and backprobe the odd colored injector wire. If the electrical side is commanding the injector on, your multimeter will beep or go from 'out of range' to some number under 1ohm. Any more questions..ask away.
11-10-2008, 05:55 PM
#14
On The Tree
Sorry if i am hijacking your thread - I just need help.
Just tried a noid test light & I got no signal. I called Wait 4 Me and he said that even w/ an 07 the engine would still start & run for 10 seconds if the VATS were still in the computer? Any truth here? I was just told by Current Performance that 07-up were different and if the Anti-theft were not disable it would send no current whatsoever to the injectors. HELP! Someone is wrong here. Jesse at Wait 4 me said he thinks I am not getting a full 12 volts to the injectors either b/c it was wired incorrectly or I powered incorrectly. I have to go buy a new voltmeter so I can check. Input very welcome.
Just tried a noid test light & I got no signal. I called Wait 4 Me and he said that even w/ an 07 the engine would still start & run for 10 seconds if the VATS were still in the computer? Any truth here? I was just told by Current Performance that 07-up were different and if the Anti-theft were not disable it would send no current whatsoever to the injectors. HELP! Someone is wrong here. Jesse at Wait 4 me said he thinks I am not getting a full 12 volts to the injectors either b/c it was wired incorrectly or I powered incorrectly. I have to go buy a new voltmeter so I can check. Input very welcome.
11-10-2008, 09:33 PM
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So heres what I have found tonight with a multimeter and test light. With the ecu power off, zero power at pink wires to injectors, grounds all show grounded. With power on, pink all have 12v, no grounds on other side. Crank it over and ground comes in and out. If I plug a test light in, it flashes on and off. Guess my injectors are stuck. I'll pull them out tomorrow and see about having them cleaned at a local injector place.
11-14-2008, 11:54 PM
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I had the injectors cleaned at a local injector place in an ultrasonic cleaner. They said they were really stuck and they had to back flow them several times to get all the grime out of them. But they ended up flowing pretty even on the flow bench. Put them in and it fired up first try tonight. After 3 months I'm one step closer to getting my car back on the road with the new power plant. Thanks for all the help.
