Dumb(?) Figured I'd ask before I do anything...

Whats the easiest and cleanest way to siphon out gas from the gas tank?

My son and I just picked up an 88 MJ that has been sitting for 2.5 years and it has a 1/4 tank of really old gas in it. We got the MJ started yesterday however the it idles really bad, and giving it gas is just as bad.

It has a rebuilt engine in it, and new plugs & wires, however they have been sitting for the last couple of years also.... But I'd figure I'd try the gas first.

So any tips on a clean job would really be appreciated.

Scotty Suyeto

scott, drop the tank and pour the gas in a bucket or something and use it for parts cleaner. take the tank over to gardena radiator, i think they do gas tank cleaning. they are on gardena blvd, across from the cable company sorta, just west of the library.

Don't forget to check and replace soft lines as nessesary. Did you replace all the other fluids?

If you pull the solenoid SOL wire off of the starter relay (so the starter doesn't turn over) and turn the key to start, the fuel pump runs continuously. Or pull the BAL connection off and hold it on the BAT or main power lug on the relay.
If you don't have the proper hose for the fuel rail connector, (with the key off and pressure released) you can remove the valve with a tire valve tool and run any old hose to a container.
Or better yet disconnect the fuel filter and run a hose from there. You can sometimes get the tank to siphon/gravity drain just by unhooking the filter. Fuel lines near the filter get kind of crispy with age, It's best to have some fuel line handy if needed.
When starting an old motor that has been sitting for awhile I usually squirt a little oil into the spark plug holes, I don't know if it helps any, but has never seemed to hurt anything.
Getting the junk out that settles to the bottom of the tank is the hard part. There is really no easy way to do it that I know of.

GrimmJeeper said:

scott, drop the tank and pour the gas in a bucket or something and use it for parts cleaner. take the tank over to gardena radiator, i think they do gas tank cleaning. they are on gardena blvd, across from the cable company sorta, just west of the library.

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Thanks Mike.. I'll give them a call.

XJensen said:

Don't forget to check and replace soft lines as nessesary. Did you replace all the other fluids?

Click to expand...

It's ALL in the works.. :viking:

Disconnect the fuel line at the tank outlet.

Replace with a line going into an appropriate receptacle (a jerrycan works neatly.)

Apply +12VDC to the pump (I don't recall which terminals you want - but I've got most RENIX wiring diagrams up at RENIXPower - groups.yahoo.com/group/RENIXPower.) It's better to use a switch than to "make" and "break" with crocodile clips, believe me!

Drain the tank.

Time how long it takes, and check the volume. This is also a good chance to check fuel pump delivery rates, and see if you need to replace the damn thing anyhow (it's been sitting for a while, so it may be needed. Especially if it runs as badly as you say - it's probably moving varnish, not gasoline.)