Fuel gauge is reading incorrectly after fuel pump change.

[Stockton]

I put a new fuel pump in.

When I first turned the car on it seemed fine. Then it went down to E from 3/4 in like 120 miles.

I went and filed up the car. It took 9.8 gallons which isn't enough to put it all the way as low as it was reading and after I filled it all up it only went back to 3/4 full and saying 290 miles to go on the tank.

It should be full and reading around 450 to the tank.

Any suggestions or ideas?

Should I unplug the battery and try to reset things?

The battery was unplugged for about a week while the car was down for the fuel pump and I was waiting for parts.

[Papachristou]

does the pump float up and down? i didnt have any trouble with my reading after installing my replacement

[Stockton]

What do you mean float? It was turned and locked into place.

I really don't feel like opening the damn thing back up.

[mike-2ptzero]

You must have hit the float(level) arm that measures how much fuel is in the tank.

[TurboQuattroPwr]

You must have hit the float(level) arm that measures how much fuel is in the tank.

Isn't that called the sending unit or is that something different?

[Stockton]

You must have hit the float(level) arm that measures how much fuel is in the tank.

Where is that?

Is that part of the whole sending unit piece that I changed?

I don't see anything about it in the Bentley Manual.

[mike-2ptzero]

Where is that?

Is that part of the whole sending unit piece that I changed?

I don't see anything about it in the Bentley Manual.

Did you change out the pump or the sending unit?

[Stockton]

Did you change out the pump or the sending unit?

What is the difference?

[Stockton]

I removed this, which is the pump built inside of this plastic housing.



That was attached to this top part which came all as one piece so it's all new.


I did this:

[mike-2ptzero]

You just replaced the pump that sits inside of its own housing. The fuel level unit is also in the tank and my guess is that the #2 electrical plug in the 2nd picture of the instructions goes to the level unit.

[Affinitive]

The tanks used in the quattro's ahve two level sending units. One mounted onto the pump basket with the electrical connector plugging into the pump flange cover (the tank cap thing that the fuel lines and electrical connectors plug into). The other level sender is on the driver side of the tank.
Sounds like you probably forgot to plug in the passenger side level sender. When you removed the tank cover to access the pump mounting basket, you probably pulled the extra connector off since the two small wires are kinda short. So without realising it, you probably reassembled everything without realising the level sender was not plugged back into the tank cover/flange.

C

[Stockton]

So you mean this wire that came out of the gas tank is connected to the level unit?


I assumed this too and wasn't sure which way it went back on. It connect either way and I couldn't remember how it came off.

Could it just be on backwards? At first it seemed fine saying I had about 3/4 tank after I replaced the pump which was right but after a few days I noticed the reading being off.

If the leveling unit isn't correct how do I fix that?

[mike-2ptzero]

Not sure. Its either the sending unit or the equalizing pump. Only way to know is to look it up.

[Stockton]

Look it up how? That's why I'm here asking.

I have a few days to use some gas up since I just filled it before I open it back up.

Now that I've done it, it's a 10 minute job to get back to but I just don't know what I'll be looking for yet.

[Affinitive]

So you mean this wire that came out of the gas tank is connected to the level unit?


I assumed this too and wasn't sure which way it went back on. It connect either way and I couldn't remember how it came off.

Could it just be on backwards? At first it seemed fine saying I had about 3/4 tank after I replaced the pump which was right but after a few days I noticed the reading being off.

If the leveling unit isn't correct how do I fix that?

Yup, that's the plug for the level sender. It doesn't matter how it's hooked up since it doesn't relley matter which direction the current flows through the level sender.

I guess I misread or misunderstood your original post. So I kinda jumped to conclusions I guess.
The level sender clips onto the side of the pump basket. Side as in the side towards the front of the car. If you use one of those small mirrors, you'll be able to see the retaining clip which keeps it in place in case you need to remove it.
Anywho, I don't know the specs off hand, I'll see if I can find or if they're avaialble on sunday (later today actually), but what you want to do to test the level sender is to hook up a OHM Meter to the two terminals of that connector you have pictured and pull it all the way up and slowly push it all the way down and you should get a nice steady change on the resistance values on the OHM Meter. Like I said, I'll find the minimum and maximum specs for you. Do this when you get some of that gas used up and open the tank again. Obviously you also wana inspect the level sender visually as well for any damage, in case it got damaged somehow while getting in there. You'll know what you're looking at when you see the metal rod with the floating thing hanging on the end of it pointing towards the driver side of the car.

C

[FourRings80]

This might help you out. A4,S4 "erratic fuel gauge repair" DIY:

http://www.audiworld.com/tech/elec.html
Good luck!

[mike-2ptzero]

This might help you out. A4,S4 "erratic fuel gauge repair" DIY:

http://www.audiworld.com/tech/elec.html
Good luck!

Here is the link to the actual article

[Affinitive]

Good Article there. Though the level senders for B6's are a little different and don't have that little cheese whiz wire. The article will still be a good reference. I was looking through some info and have not been able to find any specific specs for the level sender. VW Audi kinda sucks that way when it comes to testing and inspection specs as they often will only provide testing specs under fault code diagnosis. And I'm not nearly ambitious enough to sift through fault code charts to at the moment. Though, I do have a level sender I took off a non quattro B6 a while back and it's range is about 55 to 305 OHM's. And not long ago I had to check a P-Car boxster and it also had a range of 40 - 280 as mentioned in the article. Basicly these things are a fairly standardised (is that even a real word,....lol) thing, so you should be right within those numbers, give or take.
There is no transfer pump in this tank, only siphoning tubes and so forth. And I also found a Technical service bulletin (TSB) about the driver side level sender causing the an inaccurate fuel gauge display. The TSB makes mention of the certain production dates of the driver side level sender printed on a small tag which should be visible when removing the drivers access cover (the one with the three screws). If it's made on or before the 311th day of 2003 (311/03), then replace it regardless. If it's made on or after the 312th day of 2003, then it should be fine, though it should be checked regardless. This would also make more sense when compared to the issue of the older B5 units with the broken wire as the gauge would typically bounce around and drop dead like around tight turns as oppossed to just being inaccurate. The car being an 04 would most likely mean it has the known faulty sender in it.

I also got to thinking. A couple of days ago I put a pump into an 03 quattro and remembered that little black tube with the two 90 degree bends in it was a little bugger to keep from getting hung up on stuff. May wana just double check to make sure it's not interfeering with anything like the level sender and that the siphoning tubes inside the tank did not get disturbed/damaged somehow. Then obvioulsly prudent to check the production date on the driver side sender. maybe just weird coincedence that it finally strted causing problems.

Hope this helps

C

[initiala4]

I remember when my dealer changed mine, they changed the fuel sender as well.

[Stockton]

Cool thanks for the helpful info everyone.

When I get the gas down I'll open it back up. We've been under a hurricane/tropical storm warning today and tomorrow and I don't drive much as it is so it's taking some time using this fuel up and I just cleaned all the spilled gas out of my garage so I don't feel like doing that again.

I have one of those little telescoping mirror things so I'll take a look in there when I can.

I just don't think I can get the fuel pump out again cause I sold the specaility tool for it. If I can't get this fuel gauge fixed I'm just gunna sell the car.

[HIERLEVELZ]

BINGO!!! Stockton I bought the tool just for that. The shop that installed my 034 pump forgot to plug that harness in and I was having the very same issue.

The tanks used in the quattro's ahve two level sending units. One mounted onto the pump basket with the electrical connector plugging into the pump flange cover (the tank cap thing that the fuel lines and electrical connectors plug into). The other level sender is on the driver side of the tank.
Sounds like you probably forgot to plug in the passenger side level sender. When you removed the tank cover to access the pump mounting basket, you probably pulled the extra connector off since the two small wires are kinda short. So without realising it, you probably reassembled everything without realising the level sender was not plugged back into the tank cover/flange.

C

[B6Lovin]

your what pump?

034 as in 034 motorsport? or was that a typo and you have that "upgraded" bosch pump which i thought didnt fit?

or is it the "040" pump which is supposedly a shorter pump with near 044 capacity, and which is available through 034. lol

that's fvcking confusing hahaha

[HIERLEVELZ]

I upgraded to the "040" pump made by 034 Motorsports.

your what pump?

034 as in 034 motorsport? or was that a typo and you have that "upgraded" bosch pump which i thought didnt fit?

or is it the "040" pump which is supposedly a shorter pump with near 044 capacity, and which is available through 034. lol

that's fvcking confusing hahaha

[Stockton]

BINGO!!! Stockton I bought the tool just for that. The shop that installed my 034 pump forgot to plug that harness in and I was having the very same issue.

So what harness did they forget? The one I have pictured above that I'm holding?

[HIERLEVELZ]

So what harness did they forget? The one I have pictured above that I'm holding?

Yes that's the one!

[B6Lovin]

so the 040 pump from 034 IS a direct fit in our cars, and has no issues as far as fitment?

[Stockton]

Ok well I finally got the gas down and opened it back up. I saw the float lever arm now. On the original install I had a full tank so there was to much gas to see around in there.

It works perfect now. All I did was pretty much jiggle everything around, haha.

I pulled the float lever arm up and pressed it down gently so it went through the full range of motion, jiggled the pump in the housing to make sure it was seated nicely and if anything was caught maybe free it up.

I did disconnect this wire and flip it around cause it'll connect either way so I tried it going the other way.


Now it's all good.

[coasterjob]

Post - reincarnation.

I am having the same issue in my 04 Quattro.
I see that this is a known issue for Audi, are they correcting it under some form of warranty, or not?
I have an 04 with only 43k miles

[Toast]

guess i just joined the club, 04 quattro with new fuel pump and erratic fuel readings
going to run down the gas and attempt a fix this weekend

thanks for posting the info

[Scrwedtxboy31]

guess i just joined the club, 04 quattro with new fuel pump and erratic fuel readings
going to run down the gas and attempt a fix this weekend

thanks for posting the info

Dito, I have the same Vehicle as the OP, and the same problem. Looking into opening her up this evening. My issue is why am I smelling fuel upon start-up/warm-up? The fuel pump is literally under 3K mi new. Anyone have the same issue (smelling fuel)? or does anyone know if that issue is correlated?

[secnd2no1]

i didnt have a problem with my change.....but on full mine says 300 miles.....

[doublezero30]

any pics of the "float level arm"? im having this same issue. i was at "1/4 tank" and just filled up with only 6.9 gallons. usually its 13.

[symonsy69]

Hi, I am new to this forum and not sure how to work them, i am looking for some help/ advise on a problem i have on my a4 b6 1.8t quattro. I have just bought the car and the fuel gauge seems to show empty on the fuel gauge (when full) and full when empty!!!??? i have tried the method of uplugging fuses 15 and 28 as i have seen in another post but this didnt work (not sure if it was the same problem)

Any help is greatly received as i am a full on NOOB! :)

Thanks!!

[old guy]

I realize that this is a three year old thread but since it has been reactivated here is a possible solution to the inaccurate reading after changing out the fuel pump: Clicky click

Symonsy69: I answered your follow up thread with my best guess.

Good luck!

[iksnoved25]

Dito, I have the same Vehicle as the OP, and the same problem. Looking into opening her up this evening. My issue is why am I smelling fuel upon start-up/warm-up? The fuel pump is literally under 3K mi new. Anyone have the same issue (smelling fuel)? or does anyone know if that issue is correlated?

Reviving old post.

Fuel pump died. Had fuel pump replaced in March. Started smelling fuel. I figured they just spilled it and it would go away. Noticed whenever I would top off, smell would get worse. A week or two later, fuel level wasn't reading properly.

I'm thinking either as described above, things just need to be jiggled around or they didn't reconnect that small clip (sensor) and a gasket is either broken or not seated properly (smell).

I'd love some input on this. I haven't driven the car in 3 weeks due to the smell. It gets worse with the heat.

Thanks!

[EuroxS4]

I would say it's leaking.Pump is probably not seated all the way or the o ring rolled.

[xetura]

I realize that this is a three year old thread but since it has been reactivated here is a possible solution to the inaccurate reading after changing out the fuel pump: Clicky click

Symonsy69: I answered your follow up thread with my best guess.

Good luck!

When I replaced my fuel pump, my gauge didn't read right either. Then I found this post by Old Guy and bam, it was exactly what caused the problem. The little vent tube wasn't placed in the outer funnel shaped hole, resulting in it not reading correctly. I fixed it and its been 100% ever since.