[datsuntzxt]

Ok I have a 81 280zxt, I brought this car to my mechanic (actually my dads ) and he dont know jack about nothin !! so I have trouble with my car runing way to rich when I start it and it seems to run once warm but some times even when its warmed up It starts sputtering, and if I rev it some times it will back fire in the intake, today I started it.... was going to let it warm up and it got so rich it died and would not start at all !! I dried the plugs and it started but it was very very rich. I looked at the afm (air flow meter) with a mirror while it was runing and the flap seemed to be sticking open a little bit, is there a sensor that could tell this to do this or is the actual afm bad ? what do you guys sudgest doing first ? thanks in advance Ben

 

[zbyter]

Re: Please help 280zxt (if you can help ill send y

Ben,
a backfire through the intake usually indicates that it is running lean (not enough gas). If it backfires through the exhaust then it is rich. A good place to start is with a fuel pressure check. If I remeber correctly (which I do not) it should be in the 40's. I recently had the same problem with a 79ZX. I suspected the same thing that you do. After checking several components and much brain strain I came to the conclusion that I had a fuel delivery problem. I dropped the gas tank and found about 5 pounds of crap that resembled road tar except it was red (oxidized gas). The gas looked like rust water. I thought the tank was rusted out. I wire brushed the inside of the tank and it had no rust just the oxidized gas that had thickend and stuck to the tank. The stuff is brittle and breaks into tiny particals that plug up the sending unit screen, fuel pump screen, and gas filter. I just took it to the car wash and wire brushed it and power washed it for an hour. Put it back in and wow! No more problems. I just noticed that we are on the same network and ISP. I am in Lakewood, where are you?
Send me a e-mail if you want.
zbyter

 

[zbyter]

Re: Please help 280zxt (if you can help ill send y

Forgot,
if thats the problem what ya sending me?

 

[80ZXgoldie]

Re: Please help 280zxt (if you can help ill send y

Check your fuel injectors, sounds like one of them might not be working properly--or clogged. Place the end of a screwdriver on each injector and put your ear to the other end and listen for the flow of gas. Same thing happened to my old turbo.

 

[Lennyzcsd]

Re: Please help 280zxt (if you can help ill send y

You might want to look at the o2 sensor this is want tell the ecu how much fuel to send to the motor. If it's old replace it it probably needs it, they're only good for about 50,000 miles under the best conditions

 

[JR]

Zbyter — how do you wire brush the inside of a gas

???????????

 

[JR]

of a gas tank?

???????????

 

[zbyter]

Re: Zbyter — how do you wire brush the inside of a

JR,
I used a small wooden handled wire brush (about 4 times the size of a tooth brush) and a battery post brush, dropped the tank, stuck my arm inside the tank (into the sending unit hole) and srubbed. It may not work for every one. I am on the small side and skinny. If you can get your arm or forearm inside the tank with the brush you can rotate the tank around and get to all of the surfaces with the brush. It worked for me.
zbyter

 

[JR]

Thanks!

My arm's too fat. I've been wondering if would be worth cutting out a largish section of the top of the tank to be able to really get in there and clean (bead blast or something), then welding it back up. Seems like it would be a lot more effective than steaming and sealing as it looks like the tank has a lot of baffling in it.

 

[zbyter]

Re: Thanks!

JR,
got any teenagers in the house, or friends? I am 120 ponds and I got up to my shoulder in mine. I even got around the baffling. You can even pull the baffling out, it is held in by metal fingers (like those that you would find on a tin toy) they are twisted to be wider then the slits they go through on the baffle. If you are in the Denver area I will do it for you in a couple of weeks, I'll be laid up awhile after tomorrow. Another option is to fill it with a solvent that will desolve the oxidization. I had thought of deisl fuel or accetone and a bunch of Heat. Heat is designed to remove water and oxidization and protect the tanks suface. When I finished I coated it with WD40 to provent further corrosion. I traced the problem with my tank to a gas cap that did not seal correctly and allowed air and moisture into the tank, after sitting 17 years with a full tank of gas the leak allowed the gas to desolve and oxidize. Good luck. I would avoid the bead blasting, I have read that this will also destroy the seal. I have also read that resealing it your self hass a 50/50 chance of success. And having someone else do it is around $150 to $200. You can get a new tank from NissanParts.cc for $300.
zbyter

 

[schmaydee]

Re: Thanks!

Hey! a woman could do it!.......that would make 2 things they'd be good for........
.....if you find one that WILL. do it.........i want to take HER for my wife.........s

 

[JR]

Re: Thanks again!

Great information — had no idea the baffles were removeable. Am not near Denver, but will try to con a local kid into it. My 15-year-old daughter is starting to attract them regularly, so I might as well put 'em to work.