fuel pump losing the plot ??

[ed]

aeromotive reg - stable as a rock at all other times... suddenly dropping from 46psi to 20 in about 0.5secs?

[thechuckster]

is intake MAP doing anything like that before the regulator suddenly drops pressure?

[MWP]

Could it be a fuel pump power supply issue?
Maybe watch the fuel pumps voltage and current draw?
Might give some indications as to whats happening.

[ed]

not a MAP signal issues (zero map at that rpm/throttle)

could be a power supply issue. am getting a new pump anyway, and will look at the power supply wiring whilst there i think

[brett_celicacoupe]

restriction somewhere? fuel filter?

[Ben Wilson]

restriction somewhere? fuel filter?

I'd assume it's all new, but I have had weird experiences with partially blocked fuel filters in the past.

It might have picked up some crud from the new fuel lines??

[ed]

suppose thats possible... will see what the new pump does first though

[Ben Wilson]

We wound up replacing the injectors and the fuel pump before we worked it out...

[Mos]

There are plenty of factory cars running around with Walbros in the tank on the factory wiring without any problems. Given that a number of current sinks were removed off that circuit there were no grounds for rerunning the factory wiring in your car Ed.

I would tend to think it's more likely that the pump is mechanically binding up, due to thermal expansion of bearings/bushes/rotors etc. Depending on the quality of a product some don't like being used for extended periods at their rated limit - I have no idea what the walbro is like, but a rating isn't a rating. It does seem strange though, as a pump operates pretty much at full flow all the time - it has no idea how much fuel is coming back through the reg - the only increase on demand being pressure based...
It's also possible that as the pump labours its rpm will decrease, increasing the demand for current, which may go beyond the rating of the factory cabling.

As I said in the call, it's no issue to run a cable off your battery or circuit breaker through the existing relay but keep in mind the isolator switch will not turn off the power feed. If the relay fails closed you won't be able to turn off the pump.

It's times like these I'm glad I'm not in Sydney
Good luck!

Mos.

[ed]

ill source the power on the car side of the main breaker, thats all

[Draven]

ed: you called those guys justin posted re: cost?

[oldcorollas]

I would tend to think it's more likely that the pump is mechanically binding up, due to thermal expansion of bearings/bushes/rotors etc. Depending on the quality of a product some don't like being used for extended periods at their rated limit - I have no idea what the walbro is like, but a rating isn't a rating. It does seem strange though, as a pump operates pretty much at full flow all the time - it has no idea how much fuel is coming back through the reg - the only increase on demand being pressure based...
It's also possible that as the pump labours its rpm will decrease, increasing the demand for current, which may go beyond the rating of the factory cabling.

thats the thing... pumps run full tilt all the time.. the only diffeence here being that at idle it is not reducing the pressure required (from say, 40psi to 30 or 32psi) as would happen in normal cars so if it is getting hot with time.. doesn7t matter if you are doing a pull or not, it should still take same number of minutes of running between power drops...

if it is running out of puff from just running, then if you leave pump on for same amount of time pre the runs where it died, then it will do the same thing... i've heard of Falcon pumps runnign too hot and melthing their brackets in tank, but no idea with walbros..

surely it is a good idea to check wiring with the old pump in, and see what is happening.. before installing new pump? at least you can rule out wiring as an issue then.. (perhaps)

[clubagreenie]

Greg, going to try to get down there tomorrow and get price/avail and if there are options for location of in and outlets. Also how many we need to get at once for better price. Let me know when you want it and I'll go get it and courier it from work.

[Draven]

sms me the price they want, and what's included with that. I'm assuming it's not an off-the-shelf item, but just something they have a template lying around for... so I'd assume we can specify fitting sizes etc.

I just want to see what price is like vs what linden can make

[clubagreenie]

Good news, made to order so in/outlet locations and sizes to order. Bad news accompanying price, around $500

Linden...