Hello everyone ! First I would like to appologize for my ruff english due to living in the land were the polarbears wander the streets and where everyone talk like the chef in the Muppetshow.........

My son had troubble with an idiot whom I later turned in to the lawinforcement here in Sweden.
After a short week the idiot thought he was intitled to revenge on me and filled water and coolercement in my lovely C3 (Collector Edition) gastank ! Luckily he was dumb enough to leave traces, the empty cementbottle, so I could start draining the system emmediately and I also changed to a new fuelfilter.

After this I have been driving around houndreds of kilometers without any engineproblem (except one problem with ignition and idling which I will return to later).

Now the gasmetergauge is in top position, not top as in "full tank" but top as in "no more space to move, will soon break"-top. Its stuck up there all the time, except the last few litres when it start to wobble wildly up and down all over the place.
I supose that the floater or something else among the sensingparts, inside the tank, has been injured by the cement.

Can anyone recommend me to take away the six (?) big bolts around the top of the gasfillinghole and pull out the kit of floater and overflowtube and try to clean it all myself ? Any special procautions I should take not to trigger an accident while pulling it out ? I promise not to light a match .............
Any suggestion to what to use to solve the cement once the interior is out ?

Much later on, and probably not related to the problem above, my "enginewarning" lamp has started to go on when the engine is warm. As long as the warninglamp doesn´t light there is no problem with the idle. But when it is lit the engine dies when I stop giving pedal. The engine starts nicely again but the same thing repeats soon after, but strangely not every time it reves down to idle. Perhaps once out of four. The speedometer died the same time this problem started so I checked and found that the speedometerwire from the automatic transmission (700) has a heavy twist to it.

Can anyone tell me if the problem with the idling can relate to the nonworking speedometer ? Is the computerchip so depending on the speedsignal that it starts giving wrong signals to the fuelinjectors ? or should I start searching after faults in sparks, which BTW are new and so are all other servicerelated oils and filter stuff. I like to have happy engine.............

Off couse, I will very soon change to a new speedwire but would very much like to read some comments on the problem before I go to action.
Any difficulties her ? It seemes strait foreward to change the wire.

I am very thankfull to anyone who would take time to answer to my questions.

Regards Hebbe

P.S. The idiot is now behind bars a long time, not only for what he did to my son and myself. D.S

 

Perhaps, you should just buy a new gas tank!

 

Bend a paperclip into the shape of a horse shoe. Then find the ALDL connector under the dash, about where your knee would be on the drivers side. Jump the A and B terminals (key off), then turn the key to "on" and watch the engine light flash. First it will blink once (short pause) then two (longer pause)= code 12. Does this 3x, then the next code is displayed 3x. Write down these codes, any after code 12, then turn key off and remove jumper.
If a code has been stored, work with the first code first, because next code could just be a cause of the first. Get it?

Check and report. The speed sensor is very important along with coolant sensor =etc. Check for codes first.

Not sure if you can remove the float assembly with tank still in, removed mine during frame off resto some time ago. The float hangs on a metal rod so maybe you could repair and replace. Here in the states there are plenty of Radiator shops that also dunk fuel tanks for cleaning (acid dip) and then use a sealer to help prevent rust. But most of the time it's just easier to replace it, both for looks and price. If your tank's in good condition maybe you should have it cleaned (?).

Anyway post your results, be interested how it went.

Have fun.

 

I don't know if 78's had idle speed motors or temperature sensors/electric fans but if they did, I would check those

Like the others stated, it may be easier to just pull the gas tank if you want to disassemble the sending unit and throughly clean the inside of your tank.

 

I don't know if 78's had idle speed motors or temperature sensors/electric fans but if they did, I would check those

Like the others stated, it may be easier to just pull the gas tank if you want to disassemble the sending unit and throughly clean the inside of your tank.

 

The sending unit can't be removed through the filler neck. You'll have to drain the tank and remove the sending unit to check it out. The arm that the float is on is connected to a sensor that relays fuel level to the gauge. It sounds like the arm may be locked up or binding due to the "cement". If your hand/arm is small enough you may be able to reach into the tank to check it too...at least you can on a '72. Your filler neck may have a smaller hole. Good luck!

 

look at [url]www.corvettefaq.com
----then----FUEL----then---Fuel Sending Unit Replacement Instructions

 

Yup - going to have to drop the tank to pull the sending unit out the top.
Be careful with the steel tubes, etc. A new sending unit is quite expensive.
Once out, the arm with float will go to the pivot area.
In here, there is an electrical potentiometer. There is a metal
contact that sweeps along as the arm is moved.
Likely, some cement has dried on the contacts - except near the
low end (when the guage starts to move).
If you can clean the contacts, it should be OK.
Don't forget to get a new filter sock for inside the tank.

Good Luck