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The car is about 75% completed now and work continues at home. I have been so focused on the interior work that I have put off dealing with the mechanical issues created by the body shop. One of them is a newfound stumble and miss, accompanied by a pop in the exhaust. Since the car sat in the shop for 11 months, my money is on bad gas that has f-ed the injectors. However, given how ugly things got with the shop at the end there (police were involved and the car was forcibly removed from the shop), I would not be surprised if someone sugared my tank (or worse). The car has only been driven about 2 miles since I got it back, so if there was anything in the tank -the damage is minimal, but it's done. I checked spark, and it's 100% at all 8.

As a result, I am going to drop the tank and inspect, as well as replace the fuel filter and fuel injectors. I have purchased some brand-damn-new Bosch 30# type 3 injectors and a new filter, but I am wondering what else I should be checking into and what the best way to clean out the hard lines may be. While the tank and sender are out, I am also going to try and address the issue of the gauge never showing "full". It only goes to about 3/4. Anyone have any ideas on how to fix that outside of a new sender?
 

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Dan

Sorry to hear about the body shop problems.

I would, but don't know how, confirm if your fuel was contaminated intentionally or if the fuel is just bad from age (don't think 11 month old gas would be though)

Don't know if Blackstone Labs does gas analysis but I would cut open fuel filter to see if there is anything suspect in it first before dropping tank and replacing injectors. Maybe drain some fuel in a clean clear container to see if it looks "right"

You could get your current injectors cleaned & serviced as a alternate to buying new ones. I use www.cruzinperformance.com


On the fuel gauge thing I bought the "gas gauge fix" kit which has you wire in a adjustable pot you dial in the gauge to read at full mark when you fill it up. Has worked fine for several years on my car. Check out this link.


I remember seeing one video of a guy using a pencil eraser to clean the windings of the fuel pump sender to fix the gauge also but don't know if that was the entire process as a alternative.
 

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On the fuel gauge thing I bought the "gas gauge fix" kit which has you wire in a adjustable pot you dial in the gauge to read at full mark when you fill it up. Has worked fine for several years on my car.
BALLSS


Any "pot" or resistor can only make your gauge read lower. It can not make power to make a gauge read higher.


I would suggest testing the circuit from the body connector to prove most of your wiring and gauge work. If you read through the thread there is a easy test described. If the tank is not getting a good ground the gauge will never read high.



https://www.impalassforum.com/vBulletin/26-electrical/1300658-fuel-gauge-calibration-cluster-circuit-board.html
 

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Thanks for the suggestions, y'all. The tank ground is a great idea.

BTW - E10 has a shelf life of about 90 days. Beyond that, it starts to absorb moisture and degrade. I'll post back with some info once I get it sorted out.
 

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Is that shelf life really true ? 90 days.....

I'm in CT and had issue with my 69 vette and it sat almost a year with half tank of super in it. After i got battery, starter rebuilt and replaced engine harness, it cranked right up... that is after cranking filled the fuel bowl in the Q-jet. :)

-ALF out...
 

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Is that shelf life really true ? 90 days.....
Yes, and it is shorter in high humidity environments. My car was in a lightly air-conditioned shop through the winter, spring, and most of the summer. With the same 4-5 gallons of gas in there.

From this page:
"A gasoline/ethanol blend absorbs water until it triggers phase separation. An E10 gasoline blend has a 90-day shelf life in a closed tank, but only lasts 30 to 45 days in the vented gas tanks we have in classic cars. With a 10 percent ethanol blend you should replace the fuel in a vented tank about once a month. A lot of people recommend draining the fuel tank and fuel system. I think driving the car more often is a better solution."

There are loads of other places that all say the same thing. 60-90 days before it starts to sour. 6 months max, without a conditioner.
 

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BTW - E10 has a shelf life of about 90 days. Beyond that, it starts to absorb moisture and degrade. I'll post back with some info once I get it sorted out.
Dan, didn't know the shelf life of E10 and if your 4-5 gallons is essentially about a year old than it likely is contaminated if that is the case about E10.....unless there was also "man made" something introduced into your fuel system...which I hope is not the case

I believe we have 10% ethanol gas here in CA. I keep 5 gallon cans full I swap out every year or so for emergency generator. Never had a problem using that year old gas in any of my DD cars. It looks and smells normal when I pour it in the tank.

IDK if the gas you have in Atlanta is the same as we have here other than you likely get 93 octane and we only get 91


BALLSS


Any "pot" or resistor can only make your gauge read lower. It can not make power to make a gauge read higher.


I would suggest testing the circuit from the body connector to prove most of your wiring and gauge work. If you read through the thread there is a easy test described. If the tank is not getting a good ground the gauge will never read high.



https://www.impalassforum.com/vBulletin/26-electrical/1300658-fuel-gauge-calibration-cluster-circuit-board.html
Just read Dans 1st post again and his problem with gauge is it never reads full. IDK if the "pot" thing I got would resolve his issue

Maybe his float arm has been "bent" on previous pump service/replacement

I was just responding to Dan on what I did with my gauge several years ago. It would, as was reported to be a common problem with these gauges, stay on full for awhile and slowly go down to about 1/2 tank reading then drop quicker compared to the movement of full to 1/2 tank. Then on fill up the gauge would go past full.

This item I used once installed did resolve that issue and now the gauge reads uniformly per use of gas

I had replaced the fuel pump itself around 16 years ago with a Walbro 255 as the stock pump was fading FP. This was documented on a dyno pull so I swapped the fuel pump to the Walbro then. Just the pump and not the whole sending unit. Wiring condition, at that time, was fine and to this day fuel pressure and gauge work "normal"
 

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Just snipping to stuff I can comment on...



... I have put off dealing with the mechanical issues created by the body shop. One of them is a newfound stumble and miss, accompanied by a pop in the exhaust. Since the car sat in the shop for 11 months, my money is on bad gas that has f-ed the injectors. .....
You've not had the car for almost a year. Even discounting sabotage if 'twer me I'd have that thing on stands and close eyebalkling everything just on general principle - from front to back and then back to front. You'll catch broke (or snipped) O2 leads, or broke (or snipped) "anything else" that can be causing your symptoms. Same thing under the hood, concentrating on any number of numerous issues in the "off-idle stumble" stickie (and there are a lot). You'd hate finding out that a year in the elements without running dried up the china wall sealant and you just got a stupt intake leak.



Of course you'd also want to think like a mean-spirited little dickens and hunt for hidden broken or unconnected components - again, ones that cause your symptoms. One cute example would be a slit in the underside of the TB boot? Golf tee in any one of MANY vac hoses?


As a result, I am going to drop the tank and inspect, as well as replace the fuel filter and fuel injectors.

Good idea at any rate. It's yet an extra good reason to dump the fuel, and sounds like you're in for either a sender fix or replacement anyway.



I have purchased some brand-damn-new Bosch 30# type 3 injectors and a new filter, but I am wondering what else I should be checking into and what the best way to clean out the hard lines may be. ....
I think you're saying it's hitting on all 8 now, so if you keep your options open and do a benchcheck of your whole car as above, then you may discover something completely different is wrong and you can return those injectors.
 

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Dan asked: I have purchased some brand-damn-new Bosch 30# type 3 injectors and a new filter, but I am wondering what else I should be checking into and what the best way to clean out the hard lines may be. ....

If it twer me I would just blow some air through it with a rubber tipped air gun. The line from the tank to the filter( remove it) and then disconnect it from the front and blow hard. 125 PSI clears my sinuses.

Mark: Snowman-33
 

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Well shoot, that's my thread about the sending unit. Anybody know how to "unblur" the images?

Dan, sorry to hear about your troubles. First thing I'd check is unplug the sending unit at the bumper and see if the gauge goes past full with the ignition on so you know at least the gauge and circuit works right. Then, 90 ohms (minimum) should be full and zero ohms is empty. Look where the wiper is touching on the resistor wire and you'll figure out if maybe it's not moving enough. You can always ohm it out on the bench to see what full and empty are showing.
 

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Well shoot, that's my thread about the sending unit.
Shooting back. I had intended to give author credits but forgot. It's a great write up with lots of info. Thanks for your time and effort.

Mark: Snowman-33
 

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Yes, and it is shorter in high humidity environments. My car was in a lightly air-conditioned shop through the winter, spring, and most of the summer. With the same 4-5 gallons of gas in there.

From this page:


There are loads of other places that all say the same thing. 60-90 days before it starts to sour. 6 months max, without a conditioner.
Thanks for the link, i think i am experiencing what they say here ... "Your car will start fine, but it might lack the performance you’re expecting. When phase separation occurs the octane rating of the remaining fuel can drop by as much as three points."


Dan, didn't know the shelf life of E10 and if your 4-5 gallons is essentially about a year old than it likely is contaminated if that is the case about E10.....unless there was also "man made" something introduced into your fuel system...which I hope is not the case

I believe we have 10% ethanol gas here in CA. I keep 5 gallon cans full I swap out every year or so for emergency generator. Never had a problem using that year old gas in any of my DD cars. It looks and smells normal when I pour it in the tank.

IDK if the gas you have in Atlanta is the same as we have here other than you likely get 93 octane and we only get 91



Just read Dans 1st post again and his problem with gauge is it never reads full. IDK if the "pot" thing I got would resolve his issue

Maybe his float arm has been "bent" on previous pump service/replacement

I was just responding to Dan on what I did with my gauge several years ago. It would, as was reported to be a common problem with these gauges, stay on full for awhile and slowly go down to about 1/2 tank reading then drop quicker compared to the movement of full to 1/2 tank. Then on fill up the gauge would go past full.

This item I used once installed did resolve that issue and now the gauge reads uniformly per use of gas

I had replaced the fuel pump itself around 16 years ago with a Walbro 255 as the stock pump was fading FP. This was documented on a dyno pull so I swapped the fuel pump to the Walbro then. Just the pump and not the whole sending unit. Wiring condition, at that time, was fine and to this day fuel pressure and gauge work "normal"

Hi, in reference to stuff in RED:
I have just learned how the needle reads and stay aware of it. It is logarithmic and not linear as we all expect.
So that means you fill up and go drive and go thru 1/2 tank and needle reads 3/4 full. You go through 2/3 tank and needle reads 1/2 full.
You go through 3/4 tank and needle reads 1/4 full. That brings me to about 20 gallons, the last 1/4 on the needle is the last 3 gallons the tank can hold on my car. Low fuel light goes on when needle is in middle of the "E".
 

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I had my 454 in the shop for 15 months with a full tank of 93 octane 10% gas. When I picked it up, I started it, warmed it for about 15 minutes, and laid about 50 feet of rubber. The engine did not miss a beat.

I read an article about mixing various junk with gas to see if it causes any issues. They tried sugar in one of the experiments, and did not find any issues after running a tank of the mix through the engine.
 
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