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New guy here- '89 RS 305 TBI fuel problems

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Old Apr 1, 2009 | 06:36 PM
  #1  
martz0r's Avatar
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New guy here- '89 RS 305 TBI fuel problems

Hey guys, picked up a project car about a month back from a friends dad.

It had sat for over a year before I bought a new battery for it along with some gas and tried to start it. Well it started right up for about 5 seconds until I shut it off. Now, the car does not want to start at all. Turns over, gets spark, but that's about it.

Today I tested the fuel pump using the battery method. The pump is fine. The pump does not prime when the key is turned to the ON position though. Thinking it was the relay, I also bought one of those. Checked the fuses, they are fine. Checked the relay wires with a test light, no power is getting to the relay itself. What should be my next step? There is no gas getting to the TB. I am going to start my search for a fuel system wiring diagram. Hopefully I can figure this out soon.

Thanks!
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Old Apr 1, 2009 | 06:52 PM
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RFmaster's Avatar
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From: OC CA
Car: 75 Beast
Engine: 383 +EBL Flash
Transmission: 700R4
Axle/Gears: 4.11 with 33"
Re: New guy here- '89 RS 305 TBI fuel problems

Welcome to TGO

Relay coil poweris supplied by ECM. It is a dark green/white wire and should have +12 volts when ECM energies FP relay. It is very common for ECM to blow a transistor (Q6) which sources +12 volts to relay coil. A simple check with a DVM should verify this.

https://www.thirdgen.org/forums/dfi-...blem-fuel.html

Also, verify that you do not have VATS.

Good Luck

//RF
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Old Apr 1, 2009 | 09:25 PM
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Re: New guy here- '89 RS 305 TBI fuel problems

Thanks for the info. Anything in particular I should look for in relation to the VATS system malfunctioning? Such as lights etc.?

I will check on the green/ white wire tomorrow. I went to the junkyard (the wires going into the relay were very dirty and exposed) and got another relay off an 305 RS and replaced the relay/ wires.
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Old Apr 2, 2009 | 01:32 PM
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From: OC CA
Car: 75 Beast
Engine: 383 +EBL Flash
Transmission: 700R4
Axle/Gears: 4.11 with 33"
Re: New guy here- '89 RS 305 TBI fuel problems

Check this FAQ on VATS and Passkey system. Take a looks at your instrument cluster see if you have SECURITY light.

https://www.thirdgen.org/vats_passkey_system

//RF
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Old Apr 2, 2009 | 07:17 PM
  #5  
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Re: New guy here- '89 RS 305 TBI fuel problems

Well, I do have VATS, but when the key is turned in the ON position the light goes off after a few seconds. It doesn't flash when cranking either, indicating (hopefully) the system hasn't crapped out.

This is my first Camaro, so bare with me lol... Appreciate the information
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Old Apr 3, 2009 | 02:19 AM
  #6  
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From: OC CA
Car: 75 Beast
Engine: 383 +EBL Flash
Transmission: 700R4
Axle/Gears: 4.11 with 33"
Re: New guy here- '89 RS 305 TBI fuel problems

If SECURITY light is ok then double check if ECM is not setting VATS code 53 by shorting pins A & B of ALDL connector. Since your engine WILL CRANK and if a code 53 is displayed, that indicates that the VATS decoder module has detected a correct key resistance, and has grounded the relay coil negative wire for the start enable relay, but that the ECM is not receiving the VATS signal from the module. That can be caused by either a failure of the VATS module output which generates the signal, or Circuit 229 between the VATS module and ECM is open or shorted to ground.
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