Question about fuel injection from a newbie

[Dan Fahey]

Originally Posted by magnumv8

Actually the reason they went to 60 lbs.of fuel pressure was that the bean counters got involved in the cost reduction of the package...the horsepower was pretty much already there and it was a lot cheaper to raise the fuel pressure than it was to purchase Millions of bigger injectors to give you the same fuel volume....while a finer fuel mist IS easier to ignite the volume of fuel you are trying to burn is the same because you haven't changed the amount of air ingested and you are working with a specific A/F ratio...any horsepower increase is minimal but when working on 1 engine instead of Millions the cost is easily justified when any increase in power is good.....

D L Rambo....Stk 1300

The LS1 Injector is a big improvement over the LT1 Injector.
I like the ability to change Fuel Pressure and Tune for Power.
Could not do that as well with the LT1 Injector.
Plus the LS1 is less prone to clogging and has a finer mist!
Believe the Ford 24# Injector works well too.

D

[Ed Wright]

No reason at all you could not alter tuning by altering the fuel pressure with the factory LT1 injectors. I know NHRA Stock Eliminator racers that do it all the time. Turn the fuel pressure up on an LT1 injector, they have a finer mist as well. That is the point. Higher fuel pressure atomizes the fuel better. That is the reason for higher fuel pressures being used. Better emissions is the main reason. Very small power increase are simply a bonus.

I use injectors from FAST in mine.

[Buick6]

Check the installation instructions for the A1000 to see if they can help.

https://www.aeromotiveinc.com/tech-h...-instructions/

[Sean Marconette]

Maybe I missed it somewhere here. What size wires to the fuel pump? Have you tried a new wire from the battery to the pump and checked voltage? You could take the battery and make up leads that would go directly to the pump and check it, that eliminates all other wiring. Then start eliminating wires from there.

Sean

[Darrel Goheen]

Originally Posted by Ed Wright

No reason at all you could not alter tuning by altering the fuel pressure with the factory LT1 injectors. I know NHRA Stock Eliminator racers that do it all the time. Turn the fuel pressure up on an LT1 injector, they have a finer mist as well. That is the point. Higher fuel pressure atomizes the fuel better. That is the reason for higher fuel pressures being used. Better emissions is the main reason. Very small power increase are simply a bonus.

I use injectors from FAST in mine.

I am irritated! I believe what your are saying. It makes sense. But Holley and Fast and some others say it's best to run fuel pressure at what the injector is rated at. On most injectors they are rated at 44.5 so I've got mine right at 45. I will raise the pressure next weekend.

[Ed Wright]

Injectors are flow rated at 43.5 psi, I believe.
Not sure why they would tell you that. I'm not the only one that found power there.
Listen to who you want to.
Or, test things for yourself.

[Darrel Goheen]

Originally Posted by Ed Wright

Injectors are flow rated at 43.5 psi, I believe.
Not sure why they would tell you that. I'm not the only one that found power there.
Listen to who you want to.
Or, test things for yourself.

Yip your right. 43.5 not 44.5. Like I said I believe you and it makes sense. I'll be raising my pressure to 60 this coming weekend. Will you be at Topeka Nationals? Thanks.

[cmracing]

Originally Posted by Darrel Goheen

Yip your right. 43.5 not 44.5. Like I said I believe you and it makes sense. I'll be raising my pressure to 60 this coming weekend. Will you be at Topeka Nationals? Thanks.

You are wasting your time and money unless you fix your power issues to your fuel pump. Raising the pressure will make things worse!

You should have a 10 gauge wire feeding the fuel pump. All the EFI cars I wire have a relay in the back, close to the battery, 20 amp fuse between the battery and relay. All wiring from battery to relay to fuel pump is 10 gauge. I also use a 4 pole battery disconnect switch. The smaller terminals on the switch are used to remove the power from the relay coil so when you hit the disconnect switch the engine stops immediately even if you have a working alternator (which I highly recommend you do).

I had a friend with a BS/A swap between 42lb/hr injectors and 60lb/hr injectors within 10 minutes for back to back passes. With keeping the A/F the same, the car ran identical. Don't listen to people telling you that large injectors are a problem.

Been doing this since 1986 and I'm not on here trying to solicit business. Several here know me. I don't have time or the inclination to take on any new projects anyway, just trying to steer you straight.

If you can't get and maintain 12.5 volts at the fuel pump park the car! Get a working alternator and that pump will be MUCH happier at 13.5 to 14.0 volts. So will the injectors.

[Ed Wright]

Originally Posted by cmracing

You are wasting your time and money unless you fix your power issues to your fuel pump. Raising the pressure will make things worse!

You should have a 10 gauge wire feeding the fuel pump. All the EFI cars I wire have a relay in the back, close to the battery, 20 amp fuse between the battery and relay. All wiring from battery to relay to fuel pump is 10 gauge. I also use a 4 pole battery disconnect switch. The smaller terminals on the switch are used to remove the power from the relay coil so when you hit the disconnect switch the engine stops immediately even if you have a working alternator (which I highly recommend you do).

I had a friend with a BS/A swap between 42lb/hr injectors and 60lb/hr injectors within 10 minutes for back to back passes. With keeping the A/F the same, the car ran identical. Don't listen to people telling you that large injectors are a problem.

Been doing this since 1986 and I'm not on here trying to solicit business. Several here know me. I don't have time or the inclination to take on any new projects anyway, just trying to steer you straight.

If you can't get and maintain 12.5 volts at the fuel pump park the car! Get a working alternator and that pump will be MUCH happier at 13.5 to 14.0 volts. So will the injectors.

Why in the world would anybody think a B/SA car needed 60 lb injectors? That is forced induction stuff.

[Dan Fahey]

Originally Posted by cmracing

You are wasting your time and money unless you fix your power issues to your fuel pump. Raising the pressure will make things worse!

You should have a 10 gauge wire feeding the fuel pump. All the EFI cars I wire have a relay in the back, close to the battery, 20 amp fuse between the battery and relay. All wiring from battery to relay to fuel pump is 10 gauge. I also use a 4 pole battery disconnect switch. The smaller terminals on the switch are used to remove the power from the relay coil so when you hit the disconnect switch the engine stops immediately even if you have a working alternator (which I highly recommend you do).

I had a friend with a BS/A swap between 42lb/hr injectors and 60lb/hr injectors within 10 minutes for back to back passes. With keeping the A/F the same, the car ran identical. Don't listen to people telling you that large injectors are a problem.

Been doing this since 1986 and I'm not on here trying to solicit business. Several here know me. I don't have time or the inclination to take on any new projects anyway, just trying to steer you straight.

If you can't get and maintain 12.5 volts at the fuel pump park the car! Get a working alternator and that pump will be MUCH happier at 13.5 to 14.0 volts. So will the injectors.

This is a smart preventative maintenance mod that is overlooked.

Our B-Body Impala/Caprice community also suffer from Fuel Pump Problems.
Key issue; GM used just enough gauge size for their Harnesses.

Over time you have dodgy fuel pumps, burned wires, corroded connectors and blown fuses.

Last week the Caprice Wagon Fuel Pump fussed at 240,000 miles.
Bought a Racetronic Harness a while back which has a larger gage wire.
Installed it with a new Delco Fuel Sending Unit and Fuel Pump.

All of a sudden the Fuel Gauge works properly again and drivability improved.

D