Red86Z51

No continuity = an open. The only way to check for an open in the windings is to open up the sending unit itself and check from the connector to various points on the winding. You may also have an open at the point where the purple wire attaches (rivets) to the sender itself and your not even getting to the windings. It's just a process of elimination---start where you have known good continuity and keep working down the line until you lose it...that will be your point of failure.

lovmy90vette

My 1990 fuel gauge show full right up to the point where it is almost empty. I read the article on replacing the sending unit and was all ready to replace the parts myself. I stopped by a mechanic's shop that I trust and we took the fuel filler door off and there was no gas cap and rubber boot. Got any suggestions for me other than dropping the tank?

70ZZ3 96LT4

Frizlefak you have wrong information in your post concerning using foot pounds to tighten the cover bolts. Inch pounds, not foot pounds are used to tighten the bolts. I don't have my service manual handy to look up the inch pounds for the bolts, but it is less than 20 inch pounds. The fuel tank cover gasket GM #10140598 cost me $7.19 at the Chevrolet parts counter on 7/14/2006. Bought another one 10/14/2014 and the cost was $24.57 a big increase for just a gasket.

bowtieman55

Do you guys think the windings and contact look okay?


Also, this seems a little sketchy...

BlackPearl1

Just wanted to log on here and pass along a big thank you for this tech article. I did this yesterday on my 90 and every step followed along perfectly. My issue was that the fuel gauge would read accurately (or so it seemed) until it got down to about a half tank or slightly below and then the gauge wouldn't drop any further. I found out the hard way on two occasions that I had an issue because I ran out of gas. It has a full tank now and the gauge is reading full, so I won't really know until I drive it a while and observe the gauge dropping below a quarter tank and lower to see if the issue is really fixed, but I'm hopeful.

I'm still amazed that exposed wires submerged in a tank of gasoline doesn't ignite, but I guess that's an aspect of chemistry that I don't understand that well. I had to Google it a few times before I felt comfortable submersing the assembly again and connecting power. I half expected the car to explode when I turned on the ignition, but I'm here writing so ....

Anyway, I was planning to buy a new fuel sending unit and lay out nearly $150-$200 so for the cost of a $13 gasket I'm back in business and saved a lot of money.

Only question I have now is that in reading the article, I did torque the bolts to about 20 ft-lbs and then afterward read on here that that's too much torque. Should I loosen them and tighten again to a lesser torque?

AUTO90VETTE

So I decided to tackle my fuel gauge sending unit always showing empty. I followed a great write up on it by Frizelfrack. I wanted to add something to his write up. After cleaning to potentiometer winding and contact I put it back together and hooked it up to the connector at the tank to check its function on the dash. (Fuel pump fuse is out by the way). It worked better but was only showing every quarter tank difference. Nothing in between. I wish I would have taken pics but the contact arm is connected underneath the pivot point where it makes two contact points to send the signal to the wire for the dash gauge. My sending unit was put together with plastic type rivets and I was not brave enough to try pry it apart. I instead cleaned with carb cleaner in that area where is pivots underneath and rotated generously. Hooked it up again and it works like brand new. You can test it’s function but using your ohm meter between the black and purple wires. I believe 90ohms was full and zero was empty. Couldn’t be happier. An easy fix if you just take your time and do it right. I was also able to reuse the old tank gasket, just have to be careful with it. If your gauge is broke fix it. You can do it! Just use the awesome tech write up and clean,clean, clean!

dauntless10

the link in this article is no longer active,,,is there any way to get the entire article with photos??? thanks...live a great day...

Dave1959

Scroll up there is a PDF. Like this post if this helped, and like the PDF post, too!

Rich B.

Excellent article and great .PDF! (Original post pics have disappeared so .PDF was most appreciated!).

Thanks all!

I'll be doing the pump replacement this weekend. The gauge hasn't worked in 15+ years, so I'll give it a try too! Right now, I measure fuel with a three foot dowel...

Wandern

Is there a way you can send this to me with the pictures included? I do not know if its on my end but all of the pictures are no longer there. If not no worries just want to make sure I do everything correctly. Thanks