SaabCentral Forums banner

1 - 1 of 1 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter · #1 ·
Hi all,

I'm talking about the fuel lift pump from the tank here, not the injector.

About 30 miles from the end of a 450 mile journey yesterday it coughed, spluttered and died. Admittedly the low fuel light was on, and I was intending to fill up, but didn't make it. The light usually comes on with about 10litres/2 gallons in the tank (ie about 80 miles) and I had driven about 40. SID told me I had 25 miles till empty. I assumed I had run out, and after walking to a filling station and buying a plastic can, I put a gallon in but it wouldn't re-start. Knowing diesels can be a pain to prime/bleed I had a quick read of the book, which said to crank it for up to a minute, which I had done. As I had stopped on a slope I assumed the gallon wasn't being picked up by the pump. By various means I got to the filling station and filled the tank. But she still wouldn't restart, and after about 5 minutes of cranking the battery started to die. Time to call the AA....

He went through all the same steps, and got as far as slackening off the injectors to look for fuel/bleed, but there was none. He started to check on the fuel lift pump, but it was now dark and raining, so he gave up and called for a trailer to take me home.

Had a good look at it this morning, and through the hole in the floor under the back seat, there is a four way plug. two wires go into the housing on top of the tank, and two go off down the side of the tank somewhere. According the Haynes book, the pump is integral with the tank and all four wires go into the tank (2 for the guage, two for the pump). However, the Haynes book only covers petrol engines, so I assume the diesel has an external pump. Two of the wires have about 3.5 volts and the resistance inside the tank is about 400 ohms, which I assume is the guage sender. The other two wires have 12 volts, and disappear somewhere down the outside of the tank. The 12 volts disappears if I pull out fuse 15 (fuel pump), but they measure open circuit, and there is no current drain at all. So, it looks as if the pump has gone open circuit, and that I wasn't out of fuel after all. I cannot hear the pump run, and there seems to be no send/return fuel flow through the hoses.

So, my questions are:-
1) Anyone else had this problem? Is it common? She's just clocked up 65,000miles which seems very low for a pump failure.

2) Does the pump have some kind of "run dry" cutout, which needs to be reset?

3) Where is the pump? I cannot get underneath the car as it is too low, and as I cannot move it, I cannot get it up on ramps. I will have to borrow a set of axle stands, and jack it up to have a good look. I did find a plastic bowl (water trap?) at the side of the tank, which has a small thumbscrew underneth - this has fuel in it. But cannot see any obvious sign of the pump or where the wires/hoses go.

4) Where is the filter?

5) Is there any special way to prime/bleed the car - I'm familiar with bleeding industrial diesel engines by slackening off the injectors - is it safe to do the same here?

Thanks in advance for any info.

Alan
 
1 - 1 of 1 Posts
Top