WallyP

How did you drain the tank?

Check at the tank outlet fitting - are there electrical wires to the fitting? If so, there should be a pump inside the tank as well as the external pump. Ensure that the electrical wires to the external pump are safely placed away from any metal. Press on the relay while a helper listens for the internal pump hum. Use extreme caution to ensure that any fuel that is pumped out is safely caught.

s4bill

There is an internal pump. There are 2 sets of wires. Should I tape off the wires with electrical tape and hit the relay to see what happens?

I assume that gas may still be in the line?

I drained the tank by simply disconnecting the hose from the intake of the external pump. I pushed the hose down a little to get a little extra gas from the line. It seems that fuel flows through this pump? Is this a bad thing?

s4bill

"...Be aware that there are TWO fuel pumps in most US S4 cars. One is in the tank, other on the tank. Power supply is common. Internal pumps fail from age and intermediate hose failure inside the tank, and from trying to eat disintegrated suction strainer screens plus dirt. Given the long lay-up, it would be prudent to finish draining the tank, then pull both pumps. Plan on replacing the tank strainer and the connecting hose at minimum. Pumps would be replacement candidates too if it were my car or my customer's car. Then new fuel lines stem to stern are also in order as you set one foot over the edge of the slippery slope. "

Is there a tank strainer when there is an internal pump?

Rob Edwards

No tank strainer if there's an internal pump.

s4bill

I pulled the fuse (I believe it was number 42) cleaned it, checked it with tester on the relay. It is fine. I put it back in the fuse socket.

I put a multimeter to the terminals that are hanging form disconecting the external pump. I would get .1 mv while the car was sitting. I had someone turn the key and the voltage went to .5 mv. This seems like such a small number. I assume this is insignificant? I had someone briefly depress the relay while i had the meter connected and the meter reading went a little goofy. it went all zeros and the negative sign briefly appeared. It appears that I had the positive and negative switched. I do believe that if they hold the relay closed it will go to zero. It certainly does not read 12 vots or anything remotely close. I turned the key to off and it went back to 0 v and when depressed the relay same behavior. I did here some type ofclicking or crackling sound when the relay was depressed. It wasnt loud. It was a hair over barely audible. Not sure if it was the internal pump recognizing some voltage. I wonder if this is a short or bad ground making that noise?


When the relay is depressed, there is a tiny blue spark present when the contact is made. I assume that means the relay circuit is making contact (the inner terminals according to the schematic). The power circuit (the outer terminals) appear to be the issue.

As suggested, I am going to the store today to buy the items for a jumper.
I am going to pick up a pair of paint opener tools to remove the relay. I was going to pull the relay and put a multimeter to the outside terminals to see if there is voltage at this panel but wasnt sure if there is safe way to remove the fuse outisde a fuse puller or this paint tool.

Since, I have the pump off the car, can I connect it directly to a car battery to test it?

WallyP

Connection between the fuse and its connector is a common problem.

Yes, you can check the pump with a battery. Remember that you might still have some very flammable fuel inside the pump...

s4bill

I will pull the fuse and carefully bend the tabs on the fuse so that it makes the fit a bit tighter.

Is the fuse after the relay in the circuit?

If I pull the relay and hit one side of the multimeter with terminal power (15) and hit the other side to the ground, should I get voltage regardless of the fuse status?

I will be making my jumper tomorrow.

s4bill

I pulled the relay.

I checked at the power terminal and there was power so I put a mulitmeter to the relay and when you close the relay by hand it closes and makes contact over the power terminals. So I thought well maybe it is the fuse or fuse connection but oddly enough I had someone turn the switch on while I had a multimeter to the wires hanging from the external pump and there was 10 or 11 volts at the wires. I am not sure why it works now. Maybe there was a connection problem at the relay. I willl worry about that once I get the pumps working and fuel is pumping to the front.

So I got the voltage but no gas pumping at first. I could hear a couple clicks and then all of a sudden the internal pump start pumping gas. I hit the switch to off and didnt let it finish pumping.

I hooked the external pump which is off of the car to a battery with a switch. I connected it both ways (switching postivie and negative) and it didnt seem to do anything. So I held it in my hand and I could feel it kick.

Should it make a humming or some type of constant sound or vibration?
Should I see something move?
Is it possible that I burnt the pump from originally hooking it to a battery charger/starter?
Will it do nothing if there is no liquid?

The connector for the spark plug wire (the original problem) is arriving on Monday. This is my only transportation at the moment so I am trying to get the pump working now if I can.

I believe I am going ot order a new one anyway if the consesus is that is the prudent thing to do.

Thanks again for all of the help. I am a step closer now.

s4bill

I found a Bosch 69475 fuel pump for $100.91 w free shipping on Amazon. Is this the correct pump?

From what I read it is a turbine pump. Is this good, bad or indifferent?

If I get my original pump working would it still be prudent to replace it with this turbine pump?

Bill Ball

That's a crazy price. At least Amazon is very good for returns. It appears to be a suitable pump based on the PN. It's a bit odd for Amazon to be underselling its own partner, certainly by this much.