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Injectors won't fire

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Old 09-27-2010, 07:56 AM
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Car: 89 GTA, 80 Chevette
Engine: 350 TPI, 358 Carb
Transmission: 700R4, TH350
Axle/Gears: 9 Bolt, 8.8 with 3.73
Injectors won't fire

Here is my problem. 89 Trans Am GTA with 350 TPI. This is weird but most of the time this thing will not start. Just cranks and cranks. Sometimes it will fire right up. When you turn the key on you can hear the fuel pump run and its always got good spark. The injectors are new Bosch III's, but when it dont start you can crank it and hold onto the injectors and tell there not pulsing. Doesn't seem to be related to temperature. I dont know if it's related but I already put 2 VATS relays in it. The one in the drivers kick panel. It seems to eat them quickly. But before if I jumped the 2 big wires in the plug it would start right up. So what would allow this to have good start but not fire the injectors and when it's running it will run all day long with no trouble?
Old 09-27-2010, 06:19 PM
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Car: 82 Z28
Engine: 383 SP EFI/ 4150 TB
Transmission: T400
Axle/Gears: QP 9" 3.73
Re: Injectors won't fire

Originally Posted by SBAUERZ28
So what would allow this to have good start but not fire the injectors
VATS has two parts;
it takes out the starter and the injectors. Bypassing the starter enable relay only gets you the starter working.
Unless the computer sees the input signal from the VATS module it will not pulse the injectors so will crank all day
As it is a intermittent fault ,maybe bad connection from VATS module to ECM , maybe flaky VATS module


Old 09-28-2010, 02:32 PM
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Re: Injectors won't fire

Originally Posted by vetteoz
VATS has two parts;
it takes out the starter and the injectors. Bypassing the starter enable relay only gets you the starter working.
Unless the computer sees the input signal from the VATS module it will not pulse the injectors so will crank all day
As it is a intermittent fault ,maybe bad connection from VATS module to ECM , maybe flaky VATS module



Hey VO, always there with the great information. It's appreciated by everyone.
Old 09-28-2010, 07:37 PM
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Re: Injectors won't fire

injector fuse?
Old 09-29-2010, 01:45 AM
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Re: Injectors won't fire

Originally Posted by InjectorsPlus
Hey VO, always there with the great information. It's appreciated by everyone.

I get around
Old 09-29-2010, 04:45 AM
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Car: 89 GTA, 80 Chevette
Engine: 350 TPI, 358 Carb
Transmission: 700R4, TH350
Axle/Gears: 9 Bolt, 8.8 with 3.73
Re: Injectors won't fire

Thanks to vetteoz for that wiring info. I didn't know the VATS also controlled the injectors. I measured my key at 6000 ohms, cut the wires under the dash and wired a resistor inline. So far its been starting all the time like it should. Thanks for the help.
Old 09-29-2010, 07:20 AM
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Re: Injectors won't fire

Originally Posted by SBAUERZ28
Thanks to vetteoz for that wiring info. I didn't know the VATS also controlled the injectors. I measured my key at 6000 ohms, cut the wires under the dash and wired a resistor inline. So far its been starting all the time like it should. Thanks for the help.
Great resolution, thanks for posting the result.
Old 09-29-2010, 07:47 AM
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Re: Injectors won't fire

Originally Posted by vetteoz

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When do you sleep?
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