alonkut

Hi All,

I have a 2001 AR 2.7 Tip and recently the fuel pump started acting up.

At first the car would just stop running for no apparent reason. My indy mechanic thought he had it fixed with a new MAF, but when he took it for a test drive it died again. He tried smacking the rear passenger seat and tank with a mallet and sure enough it started - it happened once more and he got it started the same way, so his conclusion was the fuel pump - at $1100.

So, I'm taking it on as it's pretty straight forward and I've followed the guide from this site successfully - everything fit perfectly and all connections are solid.
However, now it won't start and I don't sense any power to the pump.

Is there something obvious that I need to reset? Bleed? I've checked the #28 fuse. I've replicated the position of the jumpers on the backside of the pump top plate, but should I try reversing them? I'm hesitant to think that it's a relay problem, since hitting the tank seemed to get the pump going previously... any thoughts, suggestions?

Thanks in advance!

PaperToast

im assuming the replacement pump is new?
if its not getting power, maybe a broken wire or something along those lines

alonkut

Yep, its a new pump.
I first tested power to the new pump, just to be sure, with a 12v battery charger and confirmed it works.
Then I put a meter on the pump plug and am only getting @9v +/-. So, I'm charging my battery (since I've been draining
it with long cranking) and I'm going to pop a new relay in. The wiring around the fuse plate looked solid.

I'm nearing 200,000 now and I suppose almost everything in this beast can and will go out at any moment.

PaperToast

its a long shot, check the main ground wire near the battery
ive read elsewhere on the forums that a broken/corroded ground can cause issues

alonkut

So, I cleaned the battery terminals and leads.
Put new relay in and now pushing @11.6v at the pump connection- which is great....but it still wont turn the pump on!

Put the 12v charger on and let it run for @20 seconds to confirm that fuel gets to engine - which it does.

What am I missing here?!!

I did notice that the connection has 4 slots - the 2 outer ones are where I checked for the 12v, but I see that the 2 inner carry @1.5v when the key gets inserted.
Is this a problem? I assume this is sending energy to the aux pump side...?
Even though I put the leads on the bottom side of the pump as they were mounted on the old pump- should I try reversing them?

PaperToast

why not?

mike sharples

Check the plug,seeing as its been disturbed.loose or corroded pins. Check power and ground at the plug when its plugged in,you may have 12v probing it off the pump,but if the wire is bad it will drop off when you plug it in.Back prob it,use small pin or similar to reach into the plug,very common to find bad power and grounds on wires,they dont show up just testing it unplugged.

amiram

Hope this can help

alonkut

I've pretty much covered the flow points - What's still driving me crazy about this is:

1) the harness to the pump acts and sends voltage as it should. It's at like .01v with key in and then jumps to @11.65v when cranking.
2) I've moved the harness while cranking and the voltage flow remains constant. (The wiring is stiff though.)
3) verified new pump works with 12v charger. (Fuel sent all the way to engine and it started briefly)
4) replaced relay. (because the old one was only pushing @ 9.5v)
5) replaced fuse. (just in case)
6) cleaned battery post and leads.
7) tried conduct grease on the harness to pump connection

I'm thinking that its got to be something with the harness connection? But even if the pins are being pushed back - there would still be contact...?
Going to try and dismantle, clean, and rebuild it.

Ugh!! Please- someone make me feel stupid with an obvious fix I'm not seeing!!Last edited by alonkut; Today at 04:36 PM.

PaperToast

looks like it time for you to head over here quattroworld.com Forums: allroad
many folks there with tons of experience with these cars, lot more than this forum