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Fuel Problem

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Old Apr 24, 2012 | 10:21 PM
  #1  
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From: San Diego CA
Car: 88 RS Camaro,70 chevelle,92 Geo
Engine: 305 TBI
Transmission: 5 Speed Manual
Fuel Problem

Hi there friends... i have an issue with my 88 camaro rs 5.0 LO3 Bone stock 5 speed manual tranny


it seems that every time i change my battery i have this issue... this is only the second time so it might be a coincidence


My car doesn't start and it chokes on fuel.... i disconnect the injectors cables and car starts and runs perfectly until the fuel runs out..... then i connect one injector and it starts but it runs like crap.... im guessing its the computer on board the car... every time i reset it it just sheats..... also i was changing my fuel pump relay when this happened... tried starting with both the old one and the new one.... still the same issue so im ruling it out

please help... also... the PO cut the injector cables at around 6 inches from the injectors... i reconnected them with some scotch tape... could it be that they are making contact and trowing too much fuel? ill rewire them and see
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Old Apr 25, 2012 | 12:08 AM
  #2  
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Fuel Problem

Scotch tape is bad.

First, you need to repair the wiring connections as well as possible. I would solder and heat shrink them.

Next, your fuel pump relay is probably working fine. If it runs and then dies like it runs out of fuel, it probably IS running out of fuel.

The number one culprit, in my experience, has been the oil pressure sending unit down on the block next to the oil filter. It serves two functions; one side runs your oil pressure gauge, the other side is a mechanical switch that powers the fuel pump. The relay only runs when the ECM tells it to, such as during a prime up before starting. The switch closes when it sees oil pressure and has the fuel pump running when the engine is running. If you lose oil pressure (or the engine shuts off, causing the oil pressure to stop) then the switch turns off the pump.

There are two fuses usually in little black plastic holders that are in the battery box area. One of them is the fuel pump fuse for the power that runs to that switch. This fuse could also be blown.

Good luck!
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Old Apr 25, 2012 | 01:08 AM
  #3  
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From: San Diego CA
Car: 88 RS Camaro,70 chevelle,92 Geo
Engine: 305 TBI
Transmission: 5 Speed Manual
Re: Fuel Problem

Oh theres fuel... Too mutch fuel i would say... When i disconect one injector it does turn on but verry bad... It might be a tps or a fuel pressure regulator? Also the fuel pump would run for about 2-3 mins after i turned off the car and would turn off if i opened the fuel cap
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Old Apr 25, 2012 | 01:46 AM
  #4  
KrisW's Avatar
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Fuel Problem

I've had the car run on as well. It was that oil pressure sending unit that I was telling you about. It was burned closed and just kept running until the pump burned out.

It is normal to have the pump run for up to a minute or so after you shut it off. The ECM will turn on the fuel pump relay and circulate fuel through the system to cool everything off.

You need to check fuel pressure. Go on eBay and get one of these:

http://www.ebay.com/itm/TBI-Throttle...sories&vxp=mtr

Now you can plug in a normal fuel injection fuel pressure gauge and check. If you're over 20 then you are really in trouble. I typically like mine in the 13-20 range. If you determine that your fuel pressure really is too high, then you need this:

http://www.ebay.com/itm/NEW-GM-V6-V8...item5638f0dab8

You install the adjustable regulator, then set your stocker at 13psi and call it good. Once you can get a fuel pressure reading, let us know!
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Old Apr 25, 2012 | 03:03 AM
  #5  
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From: San Diego CA
Car: 88 RS Camaro,70 chevelle,92 Geo
Engine: 305 TBI
Transmission: 5 Speed Manual
Re: Fuel Problem

Also could it be vacum related?
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Old Apr 25, 2012 | 03:12 AM
  #6  
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Fuel Problem

Anything's possible. I don't think there is an external vacuum port on your fuel pressure regulator. More likely the little rubber diaphragm is torn inside it.

When my TBI car has a vacuum leak, it surges at idle when its running or idles high. You seem to have a totally different problem if you can only make it run by cutting fuel off via the injectors.

You should do a fuel pressure reading first, before you go anywhere else. And that's after you properly fix those cut wires. No scotch tape.
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Old Apr 26, 2012 | 01:19 AM
  #7  
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From: San Diego CA
Car: 88 RS Camaro,70 chevelle,92 Geo
Engine: 305 TBI
Transmission: 5 Speed Manual
Re: Fuel Problem

So this mornig i disconected the tps and cleaned it.. Still same problem.. But i started it with 1 injector.. Let it run for about 1 min then conected the second one... Started running well .. Turned it off.. Turned on like always... Weird
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Old Apr 26, 2012 | 01:54 PM
  #8  
KrisW's Avatar
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20 Year Member
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Joined: Sep 2004
Posts: 2,777
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From: Casselberry, FLA
Car: 88 V6 'bird/89TBI bird/85 T/A
Engine: 2.8/TBI/TPI
Transmission: V8 T-5/700R4 x2
Axle/Gears: 3.42 open/2.73 open/ 3.27 9 bolt
Re: Fuel Problem

Please.... fix the wiring and then test the fuel pressure hahahahh.
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