First of all I have been out for a while and just getting back to my z car. Quick summary I had some electrical issues that were causing the car to run at 18V. This has been fixed primarily with a newer internally regulated alternator and a little rewiring. Thanks to all.

Next issue appeared to be gas delivery. The car, after some checks, appears to be running lean. Previously I have replaced the fuel pump and fuel filter (not really related at least when replaced to the lean comment). I noticed when I removed the old filter that there was a lot of small brown particles on one side of the filter, clean on other. Both the pump and filter have less than 1000 miles on them. After breaking down for about the 20th time the car has sat for 3 months or so. I was moving from one house to another and car appeared to be starving for gas and eventually broke down (some white and black smoke from exhaust, mostly white). About 2 hours later the car did restart and with same symptoms limped another 2 miles. Then all of a sudden the smoke stopped and car ran fine. I was only about 1 mile from house at this point but never the less. Bottom line is I am almost convinced that I have some rust in the tank causing the issue. I have suspected this for sometime but just not willing to take the leap and drop the tank. I removed the somewhat new filter and again some small brown particles.

Comments? Suggestions? Sorry for the long winded post. Details on dropping and cleaning tank if I am at that point?

Thanks in advance.

Here is a write up I did years ago.

http://www.classiczcars.com/forums/thread21619.html

Bonzi Lon

I think I am ready to start the process. A lot of good information and direction.

I am going to initially spray the tank with water, maybe at car wash. I will let dry for a day or two and then seal openings and apply the Muratic Acid/Water mix. I will leave this in the sealed tank for about 24 hours. Drain out the acid. Then follow up shortly after with the baking soda. Drain out baking soda. I will let the tank dry for a day or so, reseal, and then apply one coat of Red Kote. I will then blow air into each of the opening (prmarily the pick up line). I will wait a week or so before putting in fuel.

Please review and make suggestions. Not sure how long to wait before blowing with air to prevent the pick up line from clogging.

Again thanks for all the help. Hopefully I have read the info correctly.

Don't leave acid in too long.

Following Muriatic Acid with rinse then Phosphoric Acid soak is great to kill future rust

Edited October 30, 201212 yr by Blue

Blue, are you talkling about 30 minutes or so for acid? Also, first I heard of Phosphoric Acid for this. Should I do this after the baking soda?

All, I am a little cocerned about my sending unit. My gauge has not worked since I have owned the car, 1 year. It is on about 1/2 tank. The sending unit was rusty and I have cleaned up a little. What would happen if I reconnected the unti outside the tank and moved the float up an down? The windings look pretty good. All connections also look good. Float may have been stuck.

Thanks.

Yes ~ 30min to 1 hour for the Muriatic (agitate it often). Then rinse well with lots of water then hit it with the phosphoric for 30min to 1 hour followed by a rinse then dry. No need to neutralize the phosphoric as it does not flash rust like the muriatic does.

Only use the baking soda to neutralize if you skip the phosphoric.

I think the mixture would determine the time left in the tank, acid to water I mean. I think I did 50/50 for less than an hour but mine wasn't too bad and that's pretty strong. Did you ever get a good picture?

I will try and take some better photos but here is what I currently have.

I just had phone camera with me at the time.

I have since removed the sending unit. Still looking for suggestions in regards to functioning and testing outside of tank. If I could find one for $40 like one of the posts mentioned I might consider but only thing I have found is $250-400.

On my sending unit I checked the continuity between the two posts with an old analog multimeter on the resistance range with a needle instead of a digital display. That way as I slowly swung the tank sender through its range I could more easily see if the resistance smoothly varied between extremes of resistance (I measured 11 (full) to 80 (empty) ohms, others have measured closer to 8 on full). If the meter needle went to infinity frequently indicating an open circuit then I knew the connection between either the coil and the wiper arm or between the wiper arm and the post it connects to was not as good as it should be. I did the resistance checks using alligator clips to keep everything connected. My unit needed help, so after I sanded the coil of the sending unit (and soldered a wire from the wiper arm to the post it connects to) I tested it in the car by connecting it with alligator clips to the wires it normally connects to and then swung the float slowly through extremes of motion remembering my pertronix (back then) so as not to leave the key on too long for testing. Here is another post on adding a wire:

http://www.classiczcars.com/forums/showthread.php?t=35258&p=318623&viewfull=1#post318623

bhermes,

In looking at the pictures of your tank, your float appears to be turned 90 degrees to the way mine was laying on the bottom of my tank assuming your two pictures showing the float are upside down as I am perceiving them to be. Your tank looks different than mine so maybe your sending unit is supposed to look that way.

Anyone know if some Z car tank floats rest an end on the bottom of the tank as bhermes' gas tank pictures in post #44 seems to be showing?

I used red kote because of the price difference, $20 qt. at O'Reilly's or off ebay, I've put about 1,000 miles on mine since doing all the work and the glass filter I have right before the fuel rail has never had the slightest bit of color as in pink or reddish looking fuel in it and I check it every time I drive the car. I'm happy with what I did and I'd never done anything like that before.

I also would suggest the red kote product. I've used it on two separate tanks with great results.

Chase

Don't forget to treat the inside of the gas lines on the tank with the acid and then again with what ever sealant you choose. Make sure to have compressed air to clear the lines after you have put sealant through, this will make sure the stuff doesn't clog the lines.

I am going to be using the Red Kote within the next day or so on my tank. All other prep work is complete just waiting for tank to dry. The only real concern I have is cloggging the pick up line. The instructions on the Red Kote says not to blow air into the tank for at least 60 minutes. I am concerned that this stuff will have already set up and clogged the line. I am considering blowing air into the pick up line prior to the 60 minutes.

Comments?

Side topic: I have being trying to measure ressitance on my fuel snding unit. Not sure if this is not been working or my gauge is bad but gauge stuck at about 1/2 full. Althouhg I am having trouble getting consistant readings, in air, I am getting ranges from about 20 ohms to 90 ohms as I move the float through its cycle.

Comments?