JasonS

iTrader: (62)

I just purchased this 79 model yesterday and it's ben sitting for 8 years. I was able to get it running, but it won't hold an idle. I can hold it at aout 1500-2000 rpm and it runs relatively smooth, but if I let off the throttle, it will surge, miss then die. I wanted to drain the fuel tank, but there's no drain. I put 9 gallons of fresh fuel in it, (to dilute what was already there.) How difficult is it to remove the fuel tank? I also changed the fuel filter. My plan is to drain the tank and get fresh fuel in there, then see how it does. From there I'll do a complete tune-up. Initially I wasn't going to spend money on anything until I knew the motor was good. Let me know if you have any ideas.
Thank you,
~Jason

Rogue_Wulff

One way to drain the fuel tank is to remove the line going into the filter, and placing a container under it. Then just turn the key to the "on" position, and let the pump run until the container is full. After swapping containers a few times, it should remove almost all the fuel from the tank.
As for the idle problem, it could be from trash in the carb not allowing fuel to flow thru the idle curcuit, or trash in the needle and seat, causing it to flood.
After draining the tank, run the engine to drain the fuel in the carb, and try spraying some carb cleaner into the fuel inlet. Allow it to sit for a bit, and start it up. It will not run very well, or very long, on the carb cleaner, but it should at least run. cycle the carb cleaner a few times, then try adding some fresh fuel and hooking up the fuel lines. Just add a little fuel at first, along with some "pour thru" type carb cleaner. Allow the engine to run for a bit, then shut it down, allowing the fuel/cleaner to soak in the carb.
This is one of the most effective ways to revive a carb after sitting a while. If this does not work, a carb overhaul will likely be needed. I have had about 75% success with this method, and it is much cheaper than a rebuild, when it works.

1985_RX-7

They r cold natured... just let it run awhile and try it, or do a tune up, plugs wires and stuff, i did it to mine and it held an idle after a while of time at a rev

Hades12

Your points could be a little correded after sitting that long. Check for good spark on all 4 plug wires.

RotaryRocket85

thats what was wrong with mine^

JasonS

iTrader: (62)

Thanks Rogue Wulff. I'll try that.

two79rx7's

I had a 79 sitting for about 10 maybe 13 years.
I did not fool around. I pulled out the fuel tank and cleaned it all out. alot of rust and tar or goo. got it bone spottless and is ready for an interior coating.

the carb could be cloged.

after the car sat for 3 years I rebuild the carb by tearing it all the way down and soaking everything in an aggressive parts cleaner. everything was spotless. I put it all back together per the manual. then the car sat for about 10 more years after I used it for a few months.

the point is that after it sat for about ten years I assumed the carb was clean and found you must use all new gas and a spray of ether in the air cleaner to start up the car as well as adding some clean engine oil into the combustion area so the rotors will form compression. if you have good ignition it should start up soon enough. if you try it any other way you will probably burn up a starter trying.

but untill the car has been driven a bit. maybe carbon blown out of the combustion area or passages that are blocked will open up you may not find that there is enough inertia to the engine for it to run a slower idle speeds. maybe there are air leaks in the intake or other poblems to be sorted out. though my carb sat for 10 years unused it did have new gaskets put in at the rebuild and the carb was hardly used, so i did not focus there. but it took a few weeks for drivability to be predictable so I carried around a can of ether which allowed me to start the car right up. with out it I could have drained out a battery trying.

in the end if the engine is good it may take a little time but things will get better.
I hope the engien was weatherized to protect it from the cold.
hope this helps

MosesX605

Very good advice. That'd be the first thing I'd check before the carb rebuild.

Chris Boots

Possibly low compression if not carb. Try the ATF treatment. I bet that has never been done. Even if it is the carb and gets fixed do the treatment anyway. It is a good idea to doa that evry year or two so it's time for one ATF treatment.

MosesX605

Do NOT listen to this guy. Reserve the ATF treatment for stuck or non running motors. Check your points before you do anything else.