Bypassing fuel tank - temp start

jclars

Registered User
I am about to start a '89 SC that has been down for about 10 years. I have replaced the head gaskets and other upper engine gaskets, and would simply like to see if it is in fact going to run before moving it to a hot rod project. (1956 F100). I would like just enough fuel to run it for a minute or so. But I dont want to risk putting stuff into the system from the cars gas tank. Not to mention the tank at this point is very difficult to get to. I have a few electric gas pumps around, but dont know if that is all it is going to take.

Any past experiences or insight would be appreciated.

Thanks,
John L.
 
I would pull the fuel supply line off at the fuel rail, jump the fuel pump relay and just pump as much of the old gas out of there as possible. As soon as it starts to sputter, shut it off. Then get 5 gallons of fresh gas to put in it. Start it up. You could pull the line off at the fuel filter and do the same thing, I always pull it at the rail though.

Chris

You could always suck that 5 gallons back out the same way to recover your gas when done, but you want to get around that amount of gas in their to mix with the couple gallons of old gas that is still gonna be in the tank that you can't get out.
 
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You could disable the fuel pump by disconnecting the connector at the Inertia switch in the trunk ..

Then see if the engine runs if you spray Starter fluid inside the intake .. usually this is done to test a bad fuel pump. This wont run for a minute though, maybe 10 seconds at the most but it should run if all is well with the engine itself.


- Dan
 
You could disable the fuel pump by disconnecting the connector at the Inertia switch in the trunk ..

Then see if the engine runs if you spray Starter fluid inside the intake .. usually this is done to test a bad fuel pump. This wont run for a minute though, maybe 10 seconds at the most but it should run if all is well with the engine itself.


- Dan

Starter fluid on an engine that has been sitting for a long time is a bad idea. The rings and cylinders are dry and that can kill compression quick. I have always tested my fuel pumps with a fuel pressure gauge. You are going to have to drain the fuel anyway even if you dispose of the car. Why not drain the tank and fill with fresh fuel and fire it up? Then as on other poster indicated. Pull the return line off and let the pump pump out the tank into a container until empty?
 
Id be more worried about the bearings not having proper lubrication .. better to prime the engine before starting after its been sititng for 10 years than the cylinder walls, they get washed down with fuel every time you start it up cold anyways. Its just fuel vapors in the air, thats how Carburated engines work anyways .. its not like dumping raw gas down the intake but I have seen that done also. And besides, most Starter fluids sold over the counter contain "Lubricants" for the cylinder walls as well.


- Dan
 
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I would advise against even bothering to start it. You said you replaced head gaskets, so i have to assume that they were leaking or at least that the engine has a lot of miles on it. Most likely there are nasty deposits settled in the bottom of the oil pan. Since you are going to install it in another vehicle anyway, you should remove the motor and drop the pan, clean all that out, turn the motor upside down and check the rod bearings (probably shot) and replace those. Then while it is upside down, spray some WD40 up onto the cylinder walls and turn the motor over by hand to work the Wd40 into the rings.

After that, put it in the new vehicle. It will run. If you try to start it now, it may not run well at all. The rings could be stuck, injectors could be plugged, etc., and you would be forcing the engine to pull whatever nastiness is in the bottom of the pan through the bearings, etc. It's just not worth it IMO.

If you do start it, you really need to use the stock fuel pump so that it gets the proper fuel ratio. You can pump the existing gas out via the fuel line at the rail if you really want to pursue starting it.
 
Thanks all - I was beginning to wonder why the lack of response, but started down the road of draining the tank. Everyone mentions pumping it out, rather than draining. Is there no drain plug?

While I had it apart, I oiled the cylinder walls and turned it over quite freely. I lubed the lift rod ends. The insides were quite clean, without grit/gunk inside. The reason I want to start it is to see if I have it put back together correctly. I had to reassemble someone elses work, so want to confirm all connections, etc. Even if for only 10 secs, it would be enough to say I have it close enough for a "go". However, I will probably get the gas via the tank and stock pump, just to confirm the fuel delivery system works as well.

I am liking the simplicity of this engine, and will really like having more room to work on it in the large engine bay of the truck. Even with the car torn down per the pic, there were some scratched knuckles.

Thanks All!
John L.
 

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Pumped out the old gas, per your input, then put in 6 gal of fresh premium. Cranked for quite a while, as I wasnt getting any spark. That should have helped get oil partway through the system and perhaps splashed some on the conn rod bearings.

I then realized that when I took the front end off the car, I had pulled the front harness around the left fender. Doing research on the forum today about potential problems, the IRCM under the air intake was mentioned. Hmmm...

Plugged it in and it started right up. Little rough at first, but smoothed out. Not bad for lack of gaskets in the intercooler tube joints. Showed good oil pressure. So with that, it has started to get torn down again to pull this weekend and head for a home in the F100.

Thanks for the feedback and the great resource you have made this forum!

John L.
 
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