84 Injector Trouble

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Jun 13, 2006 | 05:13 PM

B3man

Thread Starter

3rd Gear

Joined: Jun 2006

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84 Injector Trouble

Hello everyone. Brand new to this forum. I'm having fuel Injector trouble on my 84. Seems that I'm not getting fuel to the injectors when I start the Vette. I only get a dribble. However, when I energize them from terminal G on the ALCL to the battery it starts fine until I shut it off and then it doesn't start back up. Any help would be deeply appreciated.

Jun 13, 2006 | 05:26 PM

Blownfuel1

Racer

Joined: May 2006

Posts: 286

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From: Alpine California

My Buddy had this a while back on his '84', and it turned out to be the weirdest thing, His coil had gone bad. He changed everything you could think of before discovering this, 2 different PROMs, one computer, and I don't even remember what else. If I remember right, he had fuel to the first throttle body, but not the second. He found something about the coil noted in one of the manuals he had, but that's about all I can tel you right now, he's over in Japan. Something to check, though.

Jun 13, 2006 | 08:12 PM

CFI-EFI

Race Director

Joined: Sep 2000

Posts: 17,298

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From: The Top of Utah

It sounds as though you possibly have a bad fuel pump relay AND a bad oil pressure switch. It is time to do some trouble shooting. There is NO way a bad coil could be responsible for a fuel pressure variance between TBs.

RACE ON!!!

Jun 13, 2006 | 08:24 PM

rick lambert

Le Mans Master

Joined: Oct 2003

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From: seattle WA

I hope you have the factory service manuals or Helms manuals for your year. If not, you're gonna need them. I do know on my 87...there is a common fusible link which feeds both FP Relay and oil switch, and the way I read mine is if it goes out..both the FP relay and oil switch..even though in parallel circuit will cause loss of power to both.

Last edited by rick lambert; Jun 13, 2006 at 08:27 PM.

Jun 14, 2006 | 12:01 AM

B3man

Thread Starter

3rd Gear

Joined: Jun 2006

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84 Injector Problem

Thanks for the replies. I do have the Haynes manual for the C4. I will check out that fuel pump relay and the oil pressure switch. Thanks again for the help.

Jun 14, 2006 | 10:41 AM

rick lambert

Le Mans Master

Joined: Oct 2003

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From: seattle WA

B3man, here's the best piece of advice I can give you...forget the Haynes, or Chiltons, spend around $100. for the FSMs or Helms manuals..you get both the service and electrical manuals, they offer trouble shooting flow charts that you'll never find in the Haynes. And when you start throwing parts at it they'll quickly add up to the cost of the manuals, and more than likley you'll have just replaced good parts trying to cure a problem. Most of us who have been here for awhile learned this also.Make sure when you get them...and sooner or later you will, that its for your year specific.

Jun 14, 2006 | 04:27 PM

B3man

Thread Starter

3rd Gear

Joined: Jun 2006

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84 Injector Problem

Hey Guys. Thanks again for all the great advice. I did pickup a fuel pump relay and it fixed me right up. Rick, I will take your advice and spend the 100.00 and be done with it. You guys take care!

Jun 14, 2006 | 04:53 PM

CFI-EFI

Race Director

Joined: Sep 2000

Posts: 17,298

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From: The Top of Utah

Quote:

Originally Posted by rick lambert

As a clarification, the FSM (Factory Service Manual) is printed by Helm Inc. and is directly available from Helm, as well as from Chevrolet.

Quote:

Originally Posted by rick lambert

And when you start throwing parts at it they'll quickly add up to the cost of the manuals, and more than likley you'll have just replaced good parts trying to cure a problem.

Speaking of throwing parts (or money) at a problem, I hope you took the time to verify that the relay was bad. Apparently it was bad, because it now runs with the replacement. How about the oil pressure switch? Have you checked or tested, it? Both supply current to run the fuel pump on parallel circuits. It takes the failure of both to deprive the fuel pump of power. You have only treated ONE symptom of the malady. The cure may not be complete.

RACE ON!!!