1987 Chevrolet Corvette Briefly Starts then Quits

Tiny
LGATTONI
  • MEMBER
  • 1987 CHEVROLET CORVETTE
  • 3.8L
  • V8
  • 2WD
  • AUTOMATIC
  • 46,000 MILES
Per your previous post I tested the fuel injection wires and found both wires are hot. I disconnected the ECU plugs, turned on the ignition, and the condition did not change. Checked the injectors resistance and all are about the same at 16. Any ideas what's going on?
Thursday, November 19th, 2015 AT 3:07 PM

2 Replies

Tiny
CARADIODOC
  • MECHANIC
  • 33,916 POSTS
I'm not sure what brought you to this point, but we rarely measure injector resistance. The coils in them rarely go open or partially-shorted, and you know multiple injectors won't magically change resistance at the same time.

You should find 12 volts on both injector wires, either when the engine is rotating, (cranking or running), or with the ignition switch just turned on, depending on the car model. The Engine Computer will ground one of those wires when it wants to turn that injector on to open it. That is done for a carefully-calculated period of time, then the ground is removed, the wire goes back to 12 volts, and the injector closes.
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Thursday, November 19th, 2015 AT 6:34 PM
Tiny
CARADIODOC
  • MECHANIC
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I'm back. Had to post my reply quickly because I was fighting a keyboard with a mind of its own.

Quitting after a few seconds is typically due to anti-theft mode being activated. I don't know if GM had that in '87, but try unlocking the doors with the key to turn that system off. The next thing is to read and record any diagnostic fault codes. Specifically, we're looking for anything related to a crankshaft position sensor or camshaft position sensor. Those are the sensor signals that tell the Engine Computer when to fire injectors and spark plugs.
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Thursday, November 19th, 2015 AT 7:00 PM

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