legacycentral bbs

Well.....I replaced the fuel sender with a new one. Tested it before I put it in the car, and it tested fine.

I put in the new one....it seemed to work fine.....however today when I went to pick my brother up, the damn gauge was bouncing around, just like it was before. There were a few times when it dropped all the way to E. Also, either I didn't fill the tank up all the way, or something's not right with the reading the gauge has. I put like 67 miles on or something, and it's under half a tank.

I'm freakin pissed!!! I'm tired of taking that damn pump in and out!! Not to mention spending money on a new sender.

I'm going to have to drive the car around with leads plugged into my multi-meter to see if I can tell if the wiring is tweaking, or if it's the senders.

here's some pics

http://www.main.experiencetherave.com:8 ... uelsender/

You're not the only one, don't feel bad.

The woman getting ready to buy the white wagon was asking me about that same problem

I have a hunch the issue is in the fuel pump connector setup. If so, I'll try and use the old 90 pump setup with the walbro.

Swapped in the 90 pump setup with the walbro. I remember why I didn't do it in the first place. The rubber keeper for the pump is different. So I had to trim it down to fit in the 1990 legacy fuel pump assembly.

Anyway....that didn't fix it. The problem is either the connector at the pump/sender, or the wiring.

I really don't want to have to drop the tank to replace that wiring......grrrr

Ignore the gauge like the rest of us do? I laughed one day down in Cape May as it bounced up and down going down a flat NJ road...

You should know me better then that by now

I can't leave it alone...

This has to be one of the most frustrating problems with these cars. Many, many posts attest to this. However, not much has been found as far as a solution, other than dropping a lit match down the hole (cue Waterworld theme). I really hope you find out what the freak is wrong because I have a guage that drops fairly quickly from full and lingers at 1/4 way too long.

Well.....I thought it was the fuel tank harness......but it's not. I had similar issues with my temp made harness.

I tested everything again when I was having the problem, and it appears to be the sub sender.

So I'm going to try that, and keep my fingers crossed.

Doesn't those years have two level sender ? Maybe it's not the one with the pump... What about the cluster, isn't there a resistance in it to makes an average of both signals to readout on the gauge ?

Don't crucify me, I'm at work far from my wiring harness books to check what I'm saying.

All the AWD cars have two senders.

I've been dealing with this problem since I put in the turbo motor....so a little over a year now. I have replaced the sender on the fuel pump side, as that seemed to be causing issues before. However when I tested things the sub unit showed to have a very high resistance.

The way the senders work, is that the two senders are wired in series, which combines the restance. The combination meter reads the voltage drop coming back from the senders and calculates the fuel level.

Here's the wiring diagram for the senders
http://www.main.experiencetherave.com:8 ... iagram.jpg

on my silver wagon I am able to pound my fist on the dashboard and the fuel gauge will come back up. I was thinking that maybe the fuel gauge itself has an issue or that perhaps the connector on the back of the cluster is not in tight. just a thought.

Yeah that could be, but I've tested the resistance of the senders when the problem is occuring and the one is way out spec. Plus I grounded the lead going to the fuel senders, and the gauge shoots up to full. So from all the testing I've done, it appears that the wiring & gauge are working correctly.

I have a hunch that these issues are caused by the addition of 10% ethonal to the gas in Houston. It's just a hunch....

Hark - how dare you say such a thing about wonderfuel! You should be ashamed.


<----- not a fan of ethanol

yeah....screw wonderfuel!

Just looking at that diagram, why not "find" the delay module as they call it -- and unplug the second sender (if you've replaced the first).

Worst case is you need to put a single sender in from a FWD car if the resistance is wrong.

I guess perhaps the best way to test to see if its the gauge or the senders is to unplug one of the senders and see if the results are just as sporadic.

Any other ideas? I've got this problem also and was going to start with those ideas up there...

--LL
Merry Xmas

To my knowledge, the 1990-1991's do not have the delay apm.

The senders combined resisistance is what makes the gauge correct. If I bypass one of the senders, the gauge will only read from half to empty.

It's a pain to pull the senders out....and I have measured the resistance on the sub-sender to be out of spec. I am going to replace that sender.

As I mentioned, I really feel the ethenol gas has caused these issues. I'll keep everyone posted once I get the sub-sender installed.

Well.....I think it's finally over.

I replaced the sub-sender the other weekend. From testing it out of the car, there is a spot 3/4 of the way to full on the sender that has infinite resistance.

I put in the new sub-sender, which I might add really wasn't that difficult to replace, and everything has seemed to be alright.

So if you have fuel gauge issues, more then likely it's the senders, and with the age of the cars, and what not....it probably wouldn't be a bad idea to replace both senders.

Here's pics
http://www.main.experiencetherave.com:8 ... elsender2/

For the record, where is the sub sender?

should be right next to the other sender. I know there's two doors on my wagon.

Are the fuel pumps on these cars intank??? is is seperate from the one sender or was it just not shown in pic? on my GM sender and pump are together.

My fuel gauge indicates at close to E there's still 6 gallons left. Thing drops really funny through the guage.

The sub-sender is directly on the other side of the tank.

Fuel pump is in tank. The main sender & pump are all one assembly. Here's some pics of the walbro install (they're mixed in with a few other pictures)

http://www.main.experiencetherave.com/s ... s/ej22t/28

thanks for the pics Josh. I was contemplating pulling my fuel pump to see how good the strainer is. With the car dying on WOT when I first got it due to a really bad clogged fuel filter, I was curious how bad the intank strainer was.

While we're on the subject, for N/A motors, do you know what the Fuel Pressure specs are supposed to be? Primed? While Running, Vacuum off regulator, etc?

Same as turbo cars, except while on boost. Here's some numbers in these two threads

http://bbs.legacycentral.org/viewtopic. ... l+pressure

http://bbs.legacycentral.org/viewtopic. ... 947#161947

the fuel senders are $65 bucks on subarugenuineparts.com?

Is that right?

I don't recall what they costs off the top of my head.

The FSM for the '91 is showing that it has the delay APM. Also what I found out with my sending unit on the pump side is that the arm for the float has a lot of play. Making it loose contact with the circuit bord that causes the resistance. I just popped the arm out of the clip so it will push the tab on the board to not loose contact. It fixed my problem for a while, but it is acting up again.