TBI Throttle Body Injection discussion and questions. L03/CFI tech and other performance enhancements.

No fuel!

Old 03-09-2019, 02:41 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Feb 2019
Posts: 6
No fuel!

Cranks but no fuel. Replaced relay,fuel pump, oil pressure sensor still nothing. Is there any other sensor that could cut fuel in any way on a 1991 RS 305 tbi? Rear impact sensor?
Jesse Mortensen is offline  
Old 03-09-2019, 03:18 PM
  #2  
Sponsor
iTrader: (81)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 11,747
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: No fuel!

Vats, no injector pulse ?
Tuned Performance is offline  
Old 03-09-2019, 08:12 PM
  #3  
Senior Member
iTrader: (8)
 
Join Date: Aug 2011
Location: Texas
Posts: 658
Car: 91 Firebird/88 Firebird/91 Formula
Engine: V6 3.1/V8 5.0/V8 5.0
Transmission: 4L60/700R4/4L60
Axle/Gears: 3.23/2.73/2.73
Re: No fuel!

Original TBI injectors?
antares57 is offline  
Old 03-10-2019, 06:21 PM
  #4  
Supreme Member
 
Join Date: Feb 2011
Posts: 1,064
Re: No fuel!

Originally Posted by Jesse Mortensen View Post
Cranks but no fuel. Replaced relay,fuel pump, oil pressure sensor still nothing. Is there any other sensor that could cut fuel in any way on a 1991 RS 305 tbi?
1. Does the fuel pump run for two seconds when the key is turned from "off" to "run"? If the fuel pump primes, it's not the fuel pump relay. If the pump runs when the engine is being cranked (has oil pressure) it's not the oil pressure switch.

2. Do you have spark? No fuel, no spark = distributor or wire harness problem. ECM requires distributor pulses to turn on the fuel injectors. No pulses, no fuel spray.

Schurkey is offline  
Old 03-10-2019, 09:35 PM
  #5  
Junior Member
Thread Starter
 
Join Date: Feb 2019
Posts: 6
Re: No fuel!

Can't hear the fuel pump run or prime. I've got spark. What is the sensor on The back of the rear end pumpkin? This problem happened driving on a hot day on the freeway. Just lost all fuel all of a sudden. Replaced the fuel pump then ran good for 1 1/2 hour drive then lost all fuel again.
Jesse Mortensen is offline  
Old 03-11-2019, 11:46 AM
  #6  
Supreme Member
 
Join Date: Feb 2011
Posts: 1,064
Re: No fuel!

Originally Posted by Jesse Mortensen View Post
Can't hear the fuel pump run or prime.
What is the voltage on the fuel pump + wire near the fuel tank when the engine is cranking? Should be within a couple of volts of battery voltage
What is the voltage on the fuel pump - wire near the fuel tank? Should be less than 2 volts, less is better.

Originally Posted by Jesse Mortensen View Post
I've got spark.
Have someone crank the engine while you listen to the injectors. You should hear them clicking. (They won't spray fuel if there's no fuel pressure.)

Originally Posted by Jesse Mortensen View Post
What is the sensor on The back of the rear end pumpkin?
No idea. Sure you're not seeing the brake plumbing, or the axle vent?

Originally Posted by Jesse Mortensen View Post
This problem happened driving on a hot day on the freeway. Just lost all fuel all of a sudden. Replaced the fuel pump then ran good for 1 1/2 hour drive then lost all fuel again.
Did you replace the short wire harness from the fuel pump to the fuel pump hanger connector? They're known for corrosion.

I figure it's most likely you have a bad wire--corroded connection, broken, pinched, something like that--between the engine compartment and the fuel pump--or between the fuel pump and ground. 'Course, it could just be a plain ol' defective pump. If it was a plugged filter or filter sock, you'd hear the pump run during "prime".

Last edited by Schurkey; 03-11-2019 at 11:53 AM.
Schurkey is offline  
Old 03-15-2019, 07:41 PM
  #7  
Junior Member
Thread Starter
 
Join Date: Feb 2019
Posts: 6
Re: No fuel!

There is a plug riveted behind the backseats under the carpet and it plugs in underneath the car above the rear end. Plug-in runs up to the fuel tank is this a sensor or just a connection point?
Jesse Mortensen is offline  
Old 03-15-2019, 08:07 PM
  #8  
Sponsor
iTrader: (81)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 11,747
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: No fuel!

The riveted connector is just a body pass through connector. No spliced in this connector. The pump power/ground and gauge sender connector is located by the tank.
Are you not getting power through C100 to the pump ?
Tuned Performance is offline  
Old 03-15-2019, 09:15 PM
  #9  
Junior Member
Thread Starter
 
Join Date: Feb 2019
Posts: 6
Re: No fuel!

Can I access any fuel tank/gauge wire’s from underneath?
Jesse Mortensen is offline  
Old 03-15-2019, 09:18 PM
  #10  
Sponsor
iTrader: (81)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 11,747
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: No fuel!

Yes, It’s next to the tank. A 3 wire connector.
Tuned Performance is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kowboy59
Engine/Drivetrain/Suspension Parts for Sale
6
11-07-2011 09:36 PM
Hokies83
Engine/Drivetrain/Suspension Parts for Sale
11
08-21-2010 12:48 PM
babybear82lilj
TBI
2
02-05-2008 05:12 PM
michael
Tech / General Engine
3
06-24-2001 08:16 AM


Thread Tools
Search this Thread
Quick Reply: No fuel!


Advertising
Featured Sponsors
Vendor Directory

Contact Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: