Okay, I swapped the resistor and it made no difference what so ever. So, tell me this, when you guys have the key turned all the way forward but with the car off, do you hear the pump running? I do not, and i think I remember that distinctive Walbro whine before start up.

I need to look at a wiring diagram and see what is in play when you turn the key. maybe a relay? But i don't see how since I have a solid 60psi while running. I'm just trying to rule out everything before I swap the whole assembly.

 

I can definitely hear the pump each time the ignition is in the ON position so something is wrong with your set up. Check your wires in the pump assembly as they can get caught up during installation

 

I will check the pump wiring but it's working, otherwise I would not have pressure while driving. FSM points to the regulator so I am pretty certain it is that. Which would suck since the Walbro was put in a brand new OEM assembly and the whole setup only has 16,000 miles on it.

 

Poopsticks!

I always heard my pump priming, even more so with the walbro.

 

It looks to me like a battery voltage issue; insufficient voltage until the alternator is running, it was cranking pretty slow IMO

the system is running on the low speed resistor at both start-up and idle, so that was never a consideration

I don't see it being a pressure regulator issue since the conditions at start up and idle are otherwise the same, if anything there should be less fuel through the regulator when the engine is running ... it wouldn't hold the pressure when it's running if everything else is the same

it could maybe be the pump not operating properly (linear) relative to voltage, but that would be a bit unusual


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Mine only whirs for 3-4 seconds , until pressure is up , then it stops . Is that also the case with yours ?

 

after further thought, if the pump is shutting off and the pressure is backing off through the regulator this might be the problem. Right now your gauge is only just coming online when the pump is shutting down in the Key On position so it is hard to tell.

Easy check is to force the fuel pump to run with the engine off as per the service manual jumper wire procedure. If you have the fuel pump on/engine off and the pressure is fine, but then goes down when you shut the pump off it is either backing off through a leaking regulator, fuel injector, or piping line.

when you run the car and shut it off, the battery voltage should be up from the alternator running and charging it, but then maybe bleeding off after sitting all night i.e. amp draw short or battery going bad. Seems like the more likely scenario off the top of my head.


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Okay, ran out and checked, voltage at the battery is 12.7. Voltage at idle is 14.3, with a low of 13.9. I went outside, removed the back seat bottom, silenced all my gauges, and I hear noting when I turn the key to the on position. I even did with my left hand leaning into the back seat to get closer with my hand on the fuel pump cover and I can't feel the vibration of the pump either with the key in the on position.

 

Oh and I just tested voltage after it has been sitting since 6PM. I will test again in the morning and then tomorrow try the FSM procedure as you mentioned. Thanks.

 

Also, I can smell fuel but there are no leaks anywhere I can see and it's a faint smell so I'm not sure if it's the exhaust or what. I checked all the factory lines and under the car as well.

 

I get the same noise. It does this regardless of how many times you turn on and off. Off cause you don't want to do it too often as you may end up flooding the engine

 

Can't see that happening as the fuel has to get past closed injectors .......

 

Fuel is leaking through the pump back into the tank, and it has to refill the lines every time you start it

Put a check valve in the fuel line just after the pump. It will keep the lines primes and working. If you still loose pressure then it is the regulator.

 

It shouldn't need a check valve, it has been working fine for three years.

 

New fuel pump assembly time?

 

I will try the FSM test on pump operation and then we will see.

 

yes, you need to run the test

did you check the battery voltage before cranking this morning?

The regulator essentially is a form of check valve in the sense that it holds pressure in the line below 55 psig or so. If it proves that the regulator leaking off during the pump shutdown condition is the only problem you could in theory install a check valve on the pump discharge line to accomplish the same thing. However, it does present a potential restriction that the fuel pump has to overcome and maybe another potential leak point. It would be a bandaid of sorts, but would probably work if the regulator leaking off is the issue

 

With the Fuel line is disconnected and you turn the key "on" you get a spurt of gas but it quickley stops. (with no fuel pressure sensor it is not the car seeing a lack of pressure) Then when turning over the engine the line will still produce no more fuel.

It seams like the pump kicks on for a second to charge the system. Then it does not turn on again until the car is running.

Try turning the KEY on and off 3-4 Times before starting and see if that makes it start right after cranking.

If it was the regulator leaking It probably would not hold enough pressure to run or you would be very lean/high fuel trims. I agree it could be voltage, but If it's not that I would guess that the fuel is leaking back through the pump into the tank.

 

Maybe we should just go to email ...


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Have we ruled out your regulator yet, even overnight my car never drops below 50 psi.

In the morning it is at roughly 52 psi, when i turn the car to the run position it does not move. When I start the car it settles at 58 psi.

The line should not lose as much pressure as you are seeing

 

I tested voltage this morning and the battery was 12.6V. I will try the FSM test on Saturday and see what's up. I am thinking of just picking a new replacement up from Advance since they have $50.00 off orders over $100.00 right now. If I need it then great, if not then I can just keep it and install an Aeromotive pump in it and have it ready for next time.

 

That 50 off 100 is likely gone already

 

Yeah it came out to $40.00 off, still a good deal though. Thanks for the heads up.

 

because of the way the FP gauge cycles on/off with the ignition you won't know for sure until running the key on/engine off fuel pump test.

It's a 5 minute job btw, I didn't realize you had such a busy social schedule in the evenings ...

 

Okay, So I followed the FSM and the pump fired to life with the key in the on position. Well right away my GF stated she smelled gas. So I again looked for a leak and nothing. So I pulled the back seat, removed fuel pump cover and noticed a small drip of fuel. Well I pressed on the the fuel line that goes into the top of the pump while the pump was jumped and running this happened.


So i shut it down, removed the line, inspected it (looks fine) and then reinstalled it and it was still leaking like a sieve. So, since the line connects fine I assume something on the fitting itself is just not sealing like it should. I guess it could also be the nipple on the pump itself but it looks fine.

I tried looking for the part number on this line and could not find anything. I also could not find any info on replacing it so I will take a look tonight and see how difficult it is.