Fero313

iTrader: (1)

I actually really wouldn't call it a problem, because the car does start but here goes...

I am prepping the car a turbo so I installed a 3rd gen pump. The car always started up right away with the original pump (less than a second). After installing the 3rd gen pump it will crank for 2-3 seconds before firing up like nothing is wrong. I assume its a priming thing but I wanted to know if it normal for it to take so long?? is this correctable??

also, there is a new sock on the pump. the old sock was broken off so the NA pump was essentially not using a sock at all!!

SureShot

I'd start by hooking up a fuel pressure test gauge.
See if the pressure builds quickly to spec, and how slow it bleeds down after shutoff.

Also check the voltage at the pump connector.
Those old thin wires from under the air box to the back may be giving some voltage drop.
If so , search "fuel pump rewire"

Fero313

iTrader: (1)

getting ahold of a gauge wed... anybody change the system so that it primes??

pistones

iTrader: (5)

i can assume that the fd pump takes more amperage to run and is more stress on the stock wiring. the "sock" wouldn't really have anything to do with it cuz it is submerged in fuel. your problem seems weird, i have a supra pump and it doesn't take any more time to start.
have you checked the health of the motor? maybe compression is not great and the extra fuel is getting past the apexes causing hard start.
if your electrical system is good then why not just swap the pump back and see if there is a difference.

Phantomkid

when you hook up the gauge look to see if there is residual pressure, after you turn the motor off does it hold pressure. Did you buy a used pump? I would not be surprised if the motor does not hold fuel pressure. And seens the pump is the only thing you changed? i would assume the old pump may have held pressure. There is a check valve on pumps, that allow the system to hold pressure. If the system does not hold pressure it may have to build it to start. When you hook up the gauge if it does not hold pressure clamp off the return line after the pressure regulator(not with bare pliers you risk damaging the line, try and use the proper tool.) If it then holds pressure the check valve is your problem. If this is the problem its not much a big deal companies sell these check valves by themselves for fairly cheap you just install it inline with the return

GTPilot

Phantomkid. Which check valve are you referring to? Is it by the tank? I have a RP pump and having the same problem that soon as I shut off the ignition, the pressure drops right down. It's the same upgrade fuel pump for both FC and FD.

Phantomkid

i believe its built into the pump, did you clamp off the return line to see if it is holding pressure?

GTPilot

Clamp it by the engine? where the high and low pressure lines are next to each other?

RotaryResurrection

iTrader: (8)

There is a check valve in the top of the pump that maintains fuel in the supply lines rather than letting it drain back. The delay you are experiencing is probably due to the checkvalve letting fuel drain from the line, and waiting for the pump to deliver new fuel to the engine.

The difference in flow or voltage would have no effect on startup, idle, or normal (easy) driving.

Try another pump, or tee in a gauge and watch what happens when you shut the car off and leave it. Most times the pressure line holds pressure for a good hour or 2 and slowly bleeds down overnight (this doesnt mean it is devoid of fuel, however, only pressure). I bet yours bleeds pressure down pretty rapidly.