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73-87 Chevy _ GMC Trucks => Fuel Systems and Drivability => Topic started by: Topgear on May 13, 2012, 07:59:40 pm

Title: Dual tank troubleshooting
Post by: Topgear on May 13, 2012, 07:59:40 pm
Just bought my '87 350TBI and I've never dealt with dual tanks before.  The PO said that the switch didn't always work, so he just stuck to the right tank and taped off the filler to the left tank so he wouldn't forget.  When I flip the switch and crank the starter, the fuel gauge does move down but the truck does not start.  I didn't try it long enough to see if the gauge would show completely empty.  If I start the truck on the right side tank, then switch to the left, it dies instantly.  There is no delay.  Is there a process for troubleshooting one of these systems?  I'm just not sure where to begin, and I don't want to dump a bunch of gas into that left tank if I need to drain it.  Thanks for any advice!

Kent
Title: Re: Dual tank troubleshooting
Post by: jaredts on May 13, 2012, 08:08:47 pm
Sounds like the fuel pump in that tank is bad.
Title: Re: Dual tank troubleshooting
Post by: VileZambonie on May 13, 2012, 08:55:31 pm
Chris,

Please modify this:
http://forum.73-87chevytrucks.com/smforum/index.php/topic,9072.0.html

With this info attached below please:

Title: Re: Dual tank troubleshooting
Post by: VileZambonie on May 13, 2012, 08:56:07 pm
And then...
Title: Re: Dual tank troubleshooting
Post by: Topgear on May 13, 2012, 09:06:06 pm
Thank you very much for posting these!  I guess there's still a good change that it's the switch (which would be nice and cheap).  Is there an easy way to get that switch out? 

Kent
Title: Re: Dual tank troubleshooting
Post by: VileZambonie on May 13, 2012, 09:17:28 pm
The switch or selector valve?
Title: Re: Dual tank troubleshooting
Post by: Topgear on May 14, 2012, 05:04:46 am
The dash switch.

Kent