|
Fuel gauge problems?
Is anybody else having a fuel gauge problem? My '08 LaCrosse gauge goes nuts when I get drive about 200 miles starting with a full tank. It can do anything from telling me I'm completely empty to simply being grossly inaccurate. A friend's wife has an '04 Buick (forget the model) which has a broken fuel gauge. There's a guy in town currently trying to sell an '08 Lucerne in " Really good condition inside and out except gas gauge doesn't work." I Google for "Buick fuel gauge problems and found out that GM cars in general have a problem because the MoCo got a bad supplier of "stepper motors", whatever they are. If you've been having a problem with your fuel gauge, what was the cause and how did you fix it? TIA.
|
Good question, good start. Can't vouch for '08's but fuel gauges used to be a rheostat or potentiometer. This was grounded in the fuel tank and as the resistance varied would change reading of the gauge. May of coarse be going from analog to digital with newer cars but the principal would be similiar. Sounds like the ground may be intermittent at the tank sender unit, may have access to it through trunk bottom (or not). Don't know what stepper motor is either, hopefully more answers to follow. https://en.m.wikipedia.org/wiki/Stepper_motor Here it is, I'd call it a servo motor though. Never had need to know about or ever troubleshoot.... Until now maybe lol. https://en.m.wikipedia.org/wiki/Servomotor So if no one knows, make up your own answer I guess. |
https://www.ebay.com/sch/i.html?_nkw...+stepper+motor Learning curve here, suppose these correspond with digital display, more accurate. Don't really notice any gauge flutter these days lol. |
Originally Posted by Rich B.
(Post 16521)
https://www.ebay.com/sch/i.html?_nkw...+stepper+motor Learning curve here, suppose these correspond with digital display, more accurate. Don't really notice any gauge flutter these days lol. |
Originally Posted by Rich B.
(Post 16519)
Good question, good start. Can't vouch for '08's but fuel gauges used to be a rheostat or potentiometer. This was grounded in the fuel tank and as the resistance varied would change reading of the gauge. May of coarse be going from analog to digital with newer cars but the principal would be similiar. Sounds like the ground may be intermittent at the tank sender unit, may have access to it through trunk bottom (or not). Don't know what stepper motor is either, hopefully more answers to follow. https://en.m.wikipedia.org/wiki/Stepper_motor Here it is, I'd call it a servo motor though. Never had need to know about or ever troubleshoot.... Until now maybe lol. https://en.m.wikipedia.org/wiki/Servomotor So if no one knows, make up your own answer I guess. |
I could be way off base here, but a motor is just that , a motor. Before going off the deep end it might be a good idea to confirm the sending unit in the tank is operating correctly.. Once you know what you are dealing with , you can go from there.
Stepper motors are used to control HVAC and idle speed/ air control functions. They are controlled some electrically and others electronically. I would still start with the sending unit and all the connections to and from it. Even the latest "Fuel Modules" still use a float to provide the signal regarding how high or low the level is in the tank. I would not be concerned with the PCM shutting down your engine due to the lack of fuel. If it quits it's because you are out of fuel or the fuel pump circuit has died and there is no fuel pressure. |
Originally Posted by hanky
(Post 16531)
I could be way off base here, but a motor is just that , a motor. Before going off the deep end it might be a good idea to confirm the sending unit in the tank is operating correctly.. Once you know what you are dealing with , you can go from there.
Stepper motors are used to control HVAC and idle speed/ air control functions. They are controlled some electrically and others electronically. I would still start with the sending unit and all the connections to and from it. Even the latest "Fuel Modules" still use a float to provide the signal regarding how high or low the level is in the tank. I would not be concerned with the PCM shutting down your engine due to the lack of fuel. If it quits it's because you are out of fuel or the fuel pump circuit has died and there is no fuel pressure. Thanks for the info about the PCM and when it would shut down the engine. I guess if it would shut down the engine based on the fuel gauge reading, that would have resulted in a massive recall. Thanks for replying! |
I don't blame you for trying to determine the easiest to correct possible cause, let's face it , the less we need to do the better.
Unfortunately , not all similar problems have the same solution. What I have suggested is based on years of experience learned, some from GM Factory Service Training and some from the school of hard knocks. The better way to tackle a problem like this is to start at the source and work your way to the gauge itself. Even if it means to get access to the sending unit and verify it is working correctly , it doesn't make much sense to start in the middle and hope you went in the right direction. |
Originally Posted by hanky
(Post 16535)
I don't blame you for trying to determine the easiest to correct possible cause, let's face it , the less we need to do the better.
Unfortunately , not all similar problems have the same solution. What I have suggested is based on years of experience learned, some from GM Factory Service Training and some from the school of hard knocks. The better way to tackle a problem like this is to start at the source and work your way to the gauge itself. Even if it means to get access to the sending unit and verify it is working correctly , it doesn't make much sense to start in the middle and hope you went in the right direction. |
Roger that JB on the Boomer SS SIlent Service, Jr. was on a few also (son). The one I recall was the Rhode Island and a few others. Doesn't talk about it much, I don't ask. He was a cook and made E8 recruiting his last few years (retired). Beat me out, I was only a E7 and retired Army(R). Also served in Navy on destroyers in the early 60's, was an ETR. I started Navy and ended Army, he started Army and ended Navy, hmm. And thank you for your service also. |
OK, now we know there is adequate talent looking at the problem
As a retired E-7 also I feel much more comfortable accepting from fellow trained personnel and will leave it there. Thank You both for your service. Will monitor and maybe can offer some helpful suggestions. With all this talent , how can we go wrong? Most folks with Buicks don't usually work on their own vehicles, but as you know there are exceptions. Happy hunting ! |
Roger on that also Hanky and thank you too on military service. I only do things these days I think I can get away with or not screw up too much. If I have enough confidence and think I can do, try it once. OK at carpentry but it takes me forever. My wood shed, only took two summers but did it. |
I always laugh when we get started on the things we screwed up. I have to rank up there with the rest. Used to visit relatives up in Scowhegan on Rt 47, always enjoyed visiting up there. As you can see , I screwed up the spelling of the town.
There is something to it because a certain amount of satisfaction is obtained in trying to help with automotive problems. I enjoy reading your posts and I'm sure you have helped a lot of people. Now I need to go and get some wood inside before we really get some snow instead of just a dusting. Thank you for all your help and advice , It is appreciated. |
Thanks on your positive reflection of my posts, know just enough to get in big trouble. Never was an auto mechanic but always on the outside looking in the window. Did all my own things though as I only had myself to cuss out that way. I can tell from your posts though you have an extensive background in the automotive field. Also always look forward to your writings. But wait, not entirely true. Did have the 63W MOS with the Army (wheeled vehicle mechanic) but was for instructional purpose. Still remember the time changing the transmission on a 2 1/2 ton down to Aberdeen Proving Grounds (school). Jacked up and mounted, told students to get away from it as we removed jack. 5 seconds later it falls out on the floor as the threads were completely stripped on retainer bolts from so much training and in and outs. Would of killed somebody for sure, that hit the pavement with one solid thump from about 3' above. Oh well, the good news was on display was that huge German cannon that ran on railroad track, think it was named Leopold? I was actually an 11B (infantry). Can't upload photos, new format here. |
Speaking of 2 1/2 ton GMC, , Was fortunate to being sent to truck driving school and when we got back the first day all we heard was , "You guys drive these things like you paid for them, drive them like they were built to run". Well the second day I learned a 2 1/2 can plow down a tree 6 in in diameter and run right over it and our instructor was pleased.
I pity the poor guys in the motor pool that had to repair them although it didn't seem to do any damage, that I know of ! I have only seen pix of Leopold and that was enough. I try not to get too personal over the net since there are people always looking for an opportunity to use the info. |
Lol too, rode a few times in a 2 1/2, never drove one. Humvee no challenge with auto tranny. So right about Internet tampering. Left FB, that's perfect environment for tampering. Understand also never give correct birth date, address or even license plate on car photo (guilty there). Think I could do just fine without any computers. This world will definitely self destruct eventually. |
From the little bit that I am aware of,
Many sites claim to have good protection of personal info, but they still get hacked into, and We never know who is minding our computer aside from us. Once you become aware of just what can be done with seemingly innocent info , I do all of my ordering over the phone hoping to at least know who I provided my card # to or phone # ,address as you mentioned.We learn to be skeptical after you see and hear what they do with your info. As we learned some wisdom with age and experience . most of us are a lot more careful than our younger generations that have yet to learn there are some not so nice people out there just waiting for you. |
| All times are GMT -5. The time now is 02:15 PM. |
© 2024 MH Sub I, LLC dba Internet Brands