Re-tuning for warmer weather?
- Thread starter "Turbo-T"
- Start date
When you max out 60# injectors and have more than 2 alky nozzles, then you might want to look at options for more fuel delivery. Double pumper is one option, KB Boost a Pump and external pump are other choices to support bigger injectors.
FWIW, double pumper costs nearly 4 times what a Walbro 340 high PSI pump costs. There are other places to spend the $375 -$400 difference.
Thanks....quick question on that link to the chart....the HP numbers listed, anyone know if that's flywheel hp or rear wheel hp?
P.S. new Walbro 340 on order
The alky kit just payed for itself as your not doing HG's and a fuel pump 
Keep the tank full when racing, it adds weight over the rear tires, keeps the pump cooler, and eliminates any starvation issues.
Once thing is what the fuel pump can do when no load is on it, another is when it has to flow. If in doubt.. replace it. That is the best scenario. Doing tests with engine not running or idling proves nothing. Your fuel pressure gauge is the one telling the truth under boost/load.
+1 on adding gasoline.. and keeping the tank topped off.
Keep the tank full when racing, it adds weight over the rear tires, keeps the pump cooler, and eliminates any starvation issues.
Once thing is what the fuel pump can do when no load is on it, another is when it has to flow. If in doubt.. replace it. That is the best scenario. Doing tests with engine not running or idling proves nothing. Your fuel pressure gauge is the one telling the truth under boost/load.
+1 on adding gasoline.. and keeping the tank topped off.
- Joined
- Feb 18, 2006
I could not disagree more.
Regardless if the motor is running or not, when the pumps start to lay down they loose their ability to make pressure. .
Test the system for pressure is step 1.
Step 2 set fp to wot target and discharging fuel into a container to be weighed.
No guessing.
If the sock on the fuel pump is clogged it will make 100 PSI pressure no problems but wont flow. Pressure does not equal flow. That is why doing tests when the motor is not under load leads to junk results.
In this case pump is fine, clogged sock is causing the issue. Open flow at no pressure proves nothing. Except it moves fuel.
If a 100 dollar pump is suspected bad, its cheaper in the grand scheme of time, troubleshooting, mental aggravation, etc to replace it. Especially on a car that its easy to do so. Once replaced you know its not the problem. Fat chance two are bad. And dont forget the filter.
Most shops charge 50-75 minimum labor to work on cars. Sir we have spent three hours diagnosing your car, and yes the pump is bad. 600.00
Fuel pumps going bad on Buicks is extremely common. That is why everyone always jumps to point that finger. Like bad stock/reman MAF's. This is a high failure item for these cars.
2 year old walbro pump suspected of problems.. end the drama and change it out
In this case pump is fine, clogged sock is causing the issue. Open flow at no pressure proves nothing. Except it moves fuel.
If a 100 dollar pump is suspected bad, its cheaper in the grand scheme of time, troubleshooting, mental aggravation, etc to replace it. Especially on a car that its easy to do so. Once replaced you know its not the problem. Fat chance two are bad. And dont forget the filter.
Most shops charge 50-75 minimum labor to work on cars. Sir we have spent three hours diagnosing your car, and yes the pump is bad. 600.00
Fuel pumps going bad on Buicks is extremely common. That is why everyone always jumps to point that finger. Like bad stock/reman MAF's. This is a high failure item for these cars.
2 year old walbro pump suspected of problems.. end the drama and change it out
- Joined
- Feb 18, 2006
Sorry Razor but again, I do not agree.
You forget the fuel system loops back to the tank and is still pumping volume even though the injectors are not opening.
It pumps more volume at lower fuel pressures. It all returns to the tank.
As the pressure is raised, volume goes down. So based on that, the most lph is achieved at lower pressures.
A clogged sock would show a gradual pressure drop after a quick spike when the pump is first turned on.
A volume issue under higher pressures is most definitely a bad pump.
You forget the fuel system loops back to the tank and is still pumping volume even though the injectors are not opening.
It pumps more volume at lower fuel pressures. It all returns to the tank.
As the pressure is raised, volume goes down. So based on that, the most lph is achieved at lower pressures.
A clogged sock would show a gradual pressure drop after a quick spike when the pump is first turned on.
A volume issue under higher pressures is most definitely a bad pump.
Similar threads
