Fuel Delivery Issues
#1
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Car: 1986 Custom Convertible Trans Am
Engine: 305 Carb
Transmission: 700r4
Axle/Gears: 3.73
Fuel Delivery Issues
Hi Guys,
After sitting for a couple of days, my carbd 86 305 with Edelbrock takes about 20 seconds of cranking to get fuel to turn over. Drives great after that with no problems all day long. I do understand this is a common problem with todays fuels and evaporation.
Questions:
1. Does my car solely rely on a mechanical pump at the block or is there another pump in addition in the tank. I hear no humming when key is turned.
2. would adding an inline flow through style pump near the tank to push some fuel up be helpful at all?
Thanks very much,
John
After sitting for a couple of days, my carbd 86 305 with Edelbrock takes about 20 seconds of cranking to get fuel to turn over. Drives great after that with no problems all day long. I do understand this is a common problem with todays fuels and evaporation.
Questions:
1. Does my car solely rely on a mechanical pump at the block or is there another pump in addition in the tank. I hear no humming when key is turned.
2. would adding an inline flow through style pump near the tank to push some fuel up be helpful at all?
Thanks very much,
John
#2
Re: Fuel Delivery Issues
Hi Guys,
After sitting for a couple of days, my carbd 86 305 with Edelbrock takes about 20 seconds of cranking to get fuel to turn over. Drives great after that with no problems all day long. I do understand this is a common problem with todays fuels and evaporation.
Questions:
1. Does my car solely rely on a mechanical pump at the block or is there another pump in addition in the tank. I hear no humming when key is turned.
2. would adding an inline flow through style pump near the tank to push some fuel up be helpful at all?
Thanks very much,
John
After sitting for a couple of days, my carbd 86 305 with Edelbrock takes about 20 seconds of cranking to get fuel to turn over. Drives great after that with no problems all day long. I do understand this is a common problem with todays fuels and evaporation.
Questions:
1. Does my car solely rely on a mechanical pump at the block or is there another pump in addition in the tank. I hear no humming when key is turned.
2. would adding an inline flow through style pump near the tank to push some fuel up be helpful at all?
Thanks very much,
John
Hi John , Here is your wiring diagram . In the upper right area you will see your fuel pump wiring , there are two fuses , a relay , the oil pressure switch and the pump itself involved in the circuit . check the fuses first and then take voltage checks at the relay while turning the key to the crank position .
PS , at the "crank" fuse disregard where it says "Hot at all times" , it's actually only got power when the key is in the crank position , hence the name "crank fuse" . Damn typos ....
#3
Supreme Member
Re: Fuel Delivery Issues
mechanical pump at the block and adding an electric won't make a difference. On mine I just crank it 10 seconds, pump the accelerator pedal three times, and hit the key again fires right up.
#4
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Car: 1986 Custom Convertible Trans Am
Engine: 305 Carb
Transmission: 700r4
Axle/Gears: 3.73
Re: Fuel Delivery Issues
So does this mean I have both a mechanical pump at the block and an electric pump in the tank? Is this a typical symptoms of the tank pump not working, but the mechanical still working?
Thanks
John
Thanks
John
#5
Supreme Member
Re: Fuel Delivery Issues
If you car sits for a while the fuel bowls in the carb can go dry and the line can drain back to the tank. Because a mechanical pump is engine driven you will have to crank it over a bit to refill everything that is normal
#6
Supreme Member
Re: Fuel Delivery Issues
An 86 with a carb should not have an electric fuel pump. Unless it started out with fuel injection., I assumed it did not since it has a carb on it now and you did not hear a fuel pump come on. So no you do have both.
Last edited by mmadden55; 08-29-2018 at 04:29 PM.
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#9
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Car: 1986 Custom Convertible Trans Am
Engine: 305 Carb
Transmission: 700r4
Axle/Gears: 3.73
Re: Fuel Delivery Issues
Thanks for all the great reply's. OrangeBird is correct and the wiring diagram confirms it. I am in the process of sorting through the wires and fuses and relay's. I can't seem to get the case off the fuse to check it. Any thoughts?
Thanks,
John
#10
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Fuel Delivery Issues
That's not a fuse; just a splice. Doesn't come apart. One side of it is probably a fusible link. Probably the right side in the photo. (looks like the "rust" colored rating) Which might conceivably be bad.
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